Physics and Astronomy › Nuclear and High Energy Physics

Particle physics theoretical and experimental studies

Works Count: 232572

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Description

This cluster of papers covers a wide range of topics in particle physics, including high-energy collider experiments, Higgs boson observation, neutrino mass, supersymmetry, quantum chromodynamics, standard model, muon anomalous magnetic moment, electroweak symmetry breaking, and dark matter.

Keywords

Particle Physics; High-Energy Collider; Higgs Boson; Neutrino Mass; Supersymmetry; Quantum Chromodynamics; Standard Model; Muon Anomalous Magnetic Moment; Electroweak Symmetry Breaking; Dark Matter

μ→eγ at a rate of one out of 109 muon decays?

1977-04-01

Peter Minkowski

A PCAC puzzle: π0→γγ in the σ-model

1969-03-01

J. S. Bell , R. Jackiw

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Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC

2012-08-14

G. Aad , T. Abajyan , B. Abbott +7 more

A search for the Standard Model Higgs boson in proton-proton collisions with the ATLAS detector at the LHC is presented. The datasets used correspond to integrated luminosities of approximately 4.8 … A search for the Standard Model Higgs boson in proton-proton collisions with the ATLAS detector at the LHC is presented. The datasets used correspond to integrated luminosities of approximately 4.8 fb^-1 collected at sqrt(s) = 7 TeV in 2011 and 5.8 fb^-1 at sqrt(s) = 8 TeV in 2012. Individual searches in the channels H->ZZ^(*)->llll, H->gamma gamma and H->WW->e nu mu nu in the 8 TeV data are combined with previously published results of searches for H->ZZ^(*), WW^(*), bbbar and tau^+tau^- in the 7 TeV data and results from improved analyses of the H->ZZ^(*)->llll and H->gamma gamma channels in the 7 TeV data. Clear evidence for the production of a neutral boson with a measured mass of 126.0 +/- 0.4(stat) +/- 0.4(sys) GeV is presented. This observation, which has a significance of 5.9 standard deviations, corresponding to a background fluctuation probability of 1.7x10^-9, is compatible with the production and decay of the Standard Model Higgs boson.

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Baryons in the expansion

1979-11-01

Edward Witten

Dynamical breaking of supersymmetry

1981-10-01

Edward Witten

DELPHES 3: a modular framework for fast simulation of a generic collider experiment

2014-02-01

J. de Favereau , C. Delaere , P. Demin +4 more

The version 3.0 of the Delphes fast-simulation is presented. The goal of Delphes is to allow the simulation of a multipurpose detector for phenomenological studies. The simulation includes a track … The version 3.0 of the Delphes fast-simulation is presented. The goal of Delphes is to allow the simulation of a multipurpose detector for phenomenological studies. The simulation includes a track propagation system embedded in a magnetic field, electromagnetic and hadron calorimeters, and a muon identification system. Physics objects that can be used for data analysis are then reconstructed from the simulated detector response. These include tracks and calorimeter deposits and high level objects such as isolated electrons, jets, taus, and missing energy. The new modular approach allows for greater flexibility in the design of the simulation and reconstruction sequence. New features such as the particle-flow reconstruction approach, crucial in the first years of the LHC, and pile-up simulation and mitigation, which is needed for the simulation of the LHC detectors in the near future, have also been implemented. The Delphes framework is not meant to be used for advanced detector studies, for which more accurate tools are needed. Although some aspects of Delphes are hadron collider specific, it is flexible enough to be adapted to the needs of electron-positron collider experiments.

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Asymptotic freedom in parton language

1977-08-01

Guido Altarelli , G. Parisi

A New Method for Combining NLO QCD with Shower Monte Carlo Algorithms

2004-11-15

Paolo Nason

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Broken Symmetries and the Masses of Gauge Bosons

1964-10-19

Peter W. Higgs

This article appears in the following collection:Letters from the Past - A PRL Retrospective2008 marked PRL's 50th anniversary. As part of the celebrations a collection of milestone Letters was started. … This article appears in the following collection:Letters from the Past - A PRL Retrospective2008 marked PRL's 50th anniversary. As part of the celebrations a collection of milestone Letters was started. The collection contains Letters that have made long-lived contributions to physics, either by announcing significant discoveries, or by initiating new areas of research.

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Global Conservation Laws and Massless Particles

1964-11-16

G. S. Guralnik , C. R. Hägen , T. W. B. Kibble

Received 12 October 1964DOI:https://doi.org/10.1103/PhysRevLett.13.585©1964 American Physical Society Received 12 October 1964DOI:https://doi.org/10.1103/PhysRevLett.13.585©1964 American Physical Society

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A general framework for implementing NLO calculations in shower Monte Carlo programs: the POWHEG BOX

2010-06-01

Simone Alioli , Paolo Nason , C. Oleari +1 more

In this work we illustrate the POWHEG BOX, a general computer code framework for implementing NLO calculations in shower Monte Carlo programs according to the POWHEG method. Aim of this … In this work we illustrate the POWHEG BOX, a general computer code framework for implementing NLO calculations in shower Monte Carlo programs according to the POWHEG method. Aim of this work is to provide an illustration of the needed theoretical ingredients, a view of how the code is organized and a description of what a user should provide in order to use it.

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Weak decays beyond leading logarithms

1996-10-01

Gerhard Buchalla , Andrzej J. Buras , Markus E. Lautenbacher

We review the present status of QCD corrections to weak decays beyond the leading-logarithmic approximation, including particle-antiparticle mixing and rare and $\mathrm{CP}$-violating decays. After presenting the basic formalism for these … We review the present status of QCD corrections to weak decays beyond the leading-logarithmic approximation, including particle-antiparticle mixing and rare and $\mathrm{CP}$-violating decays. After presenting the basic formalism for these calculations we discuss in detail the effective Hamiltonians of all decays for which the next-to-leading-order corrections are known. Subsequently, we present the phenomenological implications of these calculations. The values of various parameters are updated, in particular the mass of the newly discovered top quark. One of the central issues in this review are the theoretical uncertainties related to renormalization-scale ambiguities, which are substantially reduced by including next-to-leading-order corrections. The impact of this theoretical improvement on the determination of the Cabibbo-Kobayashi-Maskawa matrix is then illustrated. [S0034-6861(96)00304-2]

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Magnetic monopoles in unified gauge theories

1974-09-01

Gerard ’t Hooft

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Problem of Strong<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>P</mml:mi></mml:math>and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>T</mml:mi></mml:math>Invariance in the Presence of Instantons

1978-01-30

Frank Wilczek

The requirement that $P$ and $T$ be approximately conserved in the color gauge theory of strong interactions without arbitrary adjustment of parameters is analyzed. Several possibilities are identified, including one … The requirement that $P$ and $T$ be approximately conserved in the color gauge theory of strong interactions without arbitrary adjustment of parameters is analyzed. Several possibilities are identified, including one which would give a remarkable new kind of very light, long-lived pseudoscalar boson.

Parton fragmentation and string dynamics

1983-07-01

B. G. Andersson , Gösta Gustafson , G. Ingelman +1 more

Presentation of search results: theCLstechnique

2002-09-27

A. L. Read

I describe a framework for the presentation of search results which is motivated by frequentist statistics. The most well-known use of this framework is for the combined search for the … I describe a framework for the presentation of search results which is motivated by frequentist statistics. The most well-known use of this framework is for the combined search for the Higgs boson at LEP. A toy neutrino oscillations experiment is used to illustrate the rich information available in the framework for exclusion and discovery. I argue that the so-called CLs technique for setting limits is appropriate for determining exclusion intervals while the determination of confidence intervals advocated by Feldman and Cousins' method is more appropriate for treating established signals, i.e. going beyond discovery to measurement.

Supersymmetry, supergravity and particle physics

1984-08-01

Hans Peter Nilles

Remarks on the Unified Model of Elementary Particles

1962-11-01

Ziro Maki , M. Nakagawa , Shoichi Sakata

A particle mixture theory of neutrino is proposed assuming the existence of two kinds of neutrinos. Based on the neutrino-mixture theory, a possible unified model of elementary particles is constructed … A particle mixture theory of neutrino is proposed assuming the existence of two kinds of neutrinos. Based on the neutrino-mixture theory, a possible unified model of elementary particles is constructed by generalizing the Sakata-Nagoya model. Our scheme gives a natural explanation of smallness of leptonic decay rate of hyperons as well as the subtle difference of Gν's between µ-e and β-decay.

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Exclusive processes in perturbative quantum chromodynamics

1980-11-01

G. Peter Lepage , Stanley J. Brodsky

We present a systematic analysis in perturbative quantum chromodynamics (QCD) of large-momentum-transfer exclusive processes. Predictions are given for the scaling behavior, angular dependence, helicity structure, and normalization of elastic and … We present a systematic analysis in perturbative quantum chromodynamics (QCD) of large-momentum-transfer exclusive processes. Predictions are given for the scaling behavior, angular dependence, helicity structure, and normalization of elastic and inelastic form factors and large-angle exclusive scattering amplitudes for hadrons and photons. We prove that these reactions are dominated by quark and gluon subprocesses at short distances, and thus that the dimensional-counting rules for the power-law falloff of these amplitudes with momentum transfer are rigorous predictions of QCD, modulo calculable logarithmic corrections from the behavior of the hadronic wave functions at short distances. These anomalous-dimension corrections are determined by evolution equations for process-independent meson and baryon "distribution amplitudes" $\ensuremath{\varphi}({x}_{i}, Q)$ which control the valence-quark distributions in high-momentum-transfer exclusive reactions. The analysis can be carried out systematically in powers of ${\ensuremath{\alpha}}_{s}({Q}^{2})$, the QCD running coupling constant. Although the calculations are most conveniently carried out using light-cone perturbation theory and the light-cone gauge, we also present a gauge-independent analysis and relate the distribution amplitude to a gauge-invariant Bethe-Salpeter amplitude.

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A Model of Leptons

1967-11-20

Steven Weinberg

Received 17 October 1967DOI:https://doi.org/10.1103/PhysRevLett.19.1264©1967 American Physical Society Received 17 October 1967DOI:https://doi.org/10.1103/PhysRevLett.19.1264©1967 American Physical Society

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The EvtGen particle decay simulation package

2001-04-01

David Lange

Chiral perturbation theory: Expansions in the mass of the strange quark

1985-01-01

J. Gasser , H. Leutwyler

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The search for supersymmetry: Probing physics beyond the standard model

1985-01-01

Howard E. Haber , Gordon Kane

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Unity of All Elementary-Particle Forces

1974-02-25

Howard Georgi , Sheldon L. Glashow

Strong, electromagnetic, and weak forces are conjectured to arise from a single fundamental interaction based on the gauge group SU(5).Received 10 January 1974DOI:https://doi.org/10.1103/PhysRevLett.32.438©1974 American Physical Society Strong, electromagnetic, and weak forces are conjectured to arise from a single fundamental interaction based on the gauge group SU(5).Received 10 January 1974DOI:https://doi.org/10.1103/PhysRevLett.32.438©1974 American Physical Society

The hierarchy problem and new dimensions at a millimeter

1998-06-01

Nima Arkani–Hamed , Savas Dimopoulos , G. Dvali

We propose a new framework for solving the hierarchy problem which does not rely on either supersymmetry or technicolor. In this framework, the gravitational and gauge interactions become united at … We propose a new framework for solving the hierarchy problem which does not rely on either supersymmetry or technicolor. In this framework, the gravitational and gauge interactions become united at the weak scale, which we take as the only fundamental short distance scale in nature. The observed weakness of gravity on distances ≳ 1 mm is due to the existence of n≥2 new compact spatial dimensions large compared to the weak scale. The Planck scale MPl∼GN−1/2 is not a fundamental scale; its enormity is simply a consequence of the large size of the new dimensions. While gravitons can freely propagate in the new dimensions, at sub-weak energies the Standard Model (SM) fields must be localized to a 4-dimensional manifold of weak scale "thickness" in the extra dimensions. This picture leads to a number of striking signals for accelerator and laboratory experiments. For the case of n=2 new dimensions, planned sub-millimeter measurements of gravity may observe the transition from 1/r2→1/r4 Newtonian gravitation. For any number of new dimensions, the LHC and NLC could observe strong quantum gravitational interactions. Furthermore, SM particles can be kicked off our 4 dimensional manifold into the new dimensions, carrying away energy, and leading to an abrupt decrease in events with high transverse momentum pT≳ TeV. For certain compact manifolds, such particles will keep circling in the extra dimensions, periodically returning, colliding with and depositing energy to our four dimensional vacuum with frequencies of ∼1012 Hz or larger. As a concrete illustration, we construct a model with SM fields localized on the 4-dimensional throat of a vortex in 6 dimensions, with a Pati-Salam gauge symmetry SU(4)×SU(2)×SU(2) in the bulk.

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New extended model of hadrons

1974-06-15

Alan Chodos , R. L. Jaffe , K. Johnson +2 more

We propose that a strongly interacting particle is a finite region of space to which fields are confined. The confinement is accomplished in a Lorentz-invariant way by endowing the finite … We propose that a strongly interacting particle is a finite region of space to which fields are confined. The confinement is accomplished in a Lorentz-invariant way by endowing the finite region with a constant energy per unit volume, $B$. We call this finite region a "bag." The contained fields may be either fermions or bosons and may have any spin; they may or may not be coupled to one another. Equations of motion and boundary conditions are obtained from a variational principle. The confining region has no dynamical freedom but constrains the fields inside: There are no excitations of the coordinates determining the confining region. The model possesses many desirable features of hadron dynamics: (i) a parton interpretation and presumably Bjorken scaling; the confined fields are free or weakly interacting except close to the boundary; (ii) infinitely rising Regge trajectories as a consequence of the bag's finite extent; (iii) the Hagedorn degeneracy or limiting temperature; (iv) all physical hadrons are singlets under hadronic gauge symmetries. For example, in a theory of fractionally charged, "colored" quarks interacting with colored, massless gauge vector gluons, if both quark and gluon fields are confined to the bag, only color-singlet solutions exist. In addition to establishing these general properties, we present complete classical and quantum solutions for free scalars and also for free fermions inside a bag of one space and one time dimension. Both systems have linear mass-squared spectra. We demonstrate Poincar\'e invariance at the classical level in any dimension and at the quantum level for the above-mentioned explicit solutions in two dimensions. We discuss the behavior of specific solutions in one and three space dimensions. We also discuss in detail the problem of fermion boundary conditions, which follow only indirectly from the variational principle.

High-energy-physics event generation with PYTHIA 5.7 and JETSET 7.4

1994-08-01

Torbjörn Sjöstrand

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The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations

2014-07-01

Johan Alwall , Rikkert Frederix , Stefano Frixione +7 more

We discuss the theoretical bases that underpin the automation of the computations of tree-level and next-to-leading order cross sections, of their matching to parton shower simulations, and of the merging … We discuss the theoretical bases that underpin the automation of the computations of tree-level and next-to-leading order cross sections, of their matching to parton shower simulations, and of the merging of matched samples that differ by light-parton multiplicities. We present a computer program, MadGraph5_aMC@NLO, capable of handling all these computations -- parton-level fixed order, shower-matched, merged -- in a unified framework whose defining features are flexibility, high level of parallelisation, and human intervention limited to input physics quantities. We demonstrate the potential of the program by presenting selected phenomenological applications relevant to the LHC and to a 1-TeV $e^+e^-$ collider. While next-to-leading order results are restricted to QCD corrections to SM processes in the first public version, we show that from the user viewpoint no changes have to be expected in the case of corrections due to any given renormalisable Lagrangian, and that the implementation of these are well under way.

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Final report of the E821 muon anomalous magnetic moment measurement at BNL

2006-04-07

G. W. Bennett , B. Bousquet , H. Brown +7 more

We present the final report from a series of precision measurements of the muon anomalous magnetic moment, ${a}_{\ensuremath{\mu}}=(g\ensuremath{-}2)/2$. The details of the experimental method, apparatus, data taking, and analysis are … We present the final report from a series of precision measurements of the muon anomalous magnetic moment, ${a}_{\ensuremath{\mu}}=(g\ensuremath{-}2)/2$. The details of the experimental method, apparatus, data taking, and analysis are summarized. Data obtained at Brookhaven National Laboratory, using nearly equal samples of positive and negative muons, were used to deduce ${a}_{\ensuremath{\mu}}(\mathrm{\text{Expt}})=11659208.0(5.4)(3.3)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}10}$, where the statistical and systematic uncertainties are given, respectively. The combined uncertainty of 0.54 ppm represents a 14-fold improvement compared to previous measurements at CERN. The standard model value for ${a}_{\ensuremath{\mu}}$ includes contributions from virtual QED, weak, and hadronic processes. While the QED processes account for most of the anomaly, the largest theoretical uncertainty, $\ensuremath{\approx}0.55\text{ }\text{ }\mathrm{ppm}$, is associated with first-order hadronic vacuum polarization. Present standard model evaluations, based on ${e}^{+}{e}^{\ensuremath{-}}$ hadronic cross sections, lie 2.2--2.7 standard deviations below the experimental result.

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Neutrino masses in SU(2) ⊗ U(1) theories

1980-11-01

J. Schechter , J. W. F. Valle

We analyze SU(2)\ifmmode\times\else\texttimes\fi{}U(1) theories, denoted by ($n, m$), in which there are $n$ neutrinos belonging to isodoublets and $m$ neutrino isosinglets. The charged-current weak interactions are described by a rectangular … We analyze SU(2)\ifmmode\times\else\texttimes\fi{}U(1) theories, denoted by ($n, m$), in which there are $n$ neutrinos belonging to isodoublets and $m$ neutrino isosinglets. The charged-current weak interactions are described by a rectangular matrix $K$ which we explicitly parametrize. The neutral-current neutrino interactions are described by a square matrix $P={K}^{+}K$. This has the consequences that neutrinos may decay into three lighter ones and that neutrino oscillations involving neutral-current interactions should exist. The general formalism for the latter situation is given. Associated material on parametrization of unitary matrices and the quantum theory of Majorana particles is also briefly discussed.

An introduction to PYTHIA 8.2

2015-02-11

Torbjörn Sjöstrand , Stefan Ask , J. Christiansen +7 more

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Regularization and renormalization of gauge fields

1972-07-01

Gerard ’t Hooft , M. Veltman

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Lepton number as the fourth "color"

1974-07-01

Jogesh C. Pati , Abdus Salam

Universal strong, weak, and electromagnetic interactions of leptons and hadrons are generated by gauging a non-Abelian renormalizable anomaly-free subgroup of the fundamental symmetry structure $\mathrm{SU}{(4)}_{L}\ifmmode\times\else\texttimes\fi{}\mathrm{SU}{(4)}_{R}\ifmmode\times\else\texttimes\fi{}\mathrm{SU}({4}^{\ensuremath{'}})$, which unites three quartets of … Universal strong, weak, and electromagnetic interactions of leptons and hadrons are generated by gauging a non-Abelian renormalizable anomaly-free subgroup of the fundamental symmetry structure $\mathrm{SU}{(4)}_{L}\ifmmode\times\else\texttimes\fi{}\mathrm{SU}{(4)}_{R}\ifmmode\times\else\texttimes\fi{}\mathrm{SU}({4}^{\ensuremath{'}})$, which unites three quartets of "colored" baryonic quarks and the quartet of known leptons into 16-folds of chiral fermionic multiplets, with lepton number treated as the fourth "color" quantum number. Experimental consequences of this scheme are discussed. These include (1) the emergence and effects of exotic gauge mesons carrying both baryonic as well as leptonic quantum numbers, particularly in semileptonic processes, (2) the manifestation of anomalous strong interactions among leptonic and semileptonic processes at high energies, (3) the independent possibility of baryon-lepton number violation in quark and proton decays, and (4) the occurrence of ($V+A$) weak-current effects.

Parton distributions for the LHC

2009-07-03

A. D. Martin , W. J. Stirling , R. S. Thorne +1 more

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The CMS experiment at the CERN LHC

2008-08-14

the CMS Collaboration , S. Chatrchyan , G. Hmayakyan +7 more

The Compact Muon Solenoid (CMS) detector is described. The detector operates at the Large Hadron Collider (LHC) at CERN. It was conceived to study proton-proton (and lead-lead) collisions at a … The Compact Muon Solenoid (CMS) detector is described. The detector operates at the Large Hadron Collider (LHC) at CERN. It was conceived to study proton-proton (and lead-lead) collisions at a centre-of-mass energy of 14 TeV (5.5 TeV nucleon-nucleon) and at luminosities up to 1034 cm−2 s−1 (1027 cm−2 s−1). At the core of the CMS detector sits a high-magnetic-field and large-bore superconducting solenoid surrounding an all-silicon pixel and strip tracker, a lead-tungstate scintillating-crystals electromagnetic calorimeter, and a brass-scintillator sampling hadron calorimeter. The iron yoke of the flux-return is instrumented with four stations of muon detectors covering most of the 4π solid angle. Forward sampling calorimeters extend the pseudorapidity coverage to high values (|η| ⩽ 5) assuring very good hermeticity. The overall dimensions of the CMS detector are a length of 21.6 m, a diameter of 14.6 m and a total weight of 12500 t.

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FeynRules 2.0 — A complete toolbox for tree-level phenomenology

2014-05-04

Adam Alloul , Neil D. Christensen , Céline Degrande +2 more

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Radiative Corrections as the Origin of Spontaneous Symmetry Breaking

1973-03-15

Sidney Coleman , Erick J. Weinberg

We investigate the possibility that radiative corrections may produce spontaneous symmetry breakdown in theories for which the semiclassical (tree) approximation does not indicate such breakdown. The simplest model in which … We investigate the possibility that radiative corrections may produce spontaneous symmetry breakdown in theories for which the semiclassical (tree) approximation does not indicate such breakdown. The simplest model in which this phenomenon occurs is the electrodynamics of massless scalar mesons. We find (for small coupling constants) that this theory more closely resembles the theory with an imaginary mass (the Abelian Higgs model) than one with a positive mass; spontaneous symmetry breaking occurs, and the theory becomes a theory of a massive vector meson and a massive scalar meson. The scalar-to-vector mass ratio is computable as a power series in $e$, the electromagnetic coupling constant. We find, to lowest order, $\frac{{m}^{2}(S)}{{m}^{2}(V)}=(\frac{3}{2\ensuremath{\pi}})(\frac{{e}^{2}}{4\ensuremath{\pi}})$. We extend our analysis to non-Abelian gauge theories, and find qualitatively similar results. Our methods are also applicable to theories in which the tree approximation indicates the occurrence of spontaneous symmetry breakdown, but does not give complete information about its character. (This typically occurs when the scalar-meson part of the Lagrangian admits a greater symmetry group than the total Lagrangian.) We indicate how to use our methods in these cases.

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A brief introduction to PYTHIA 8.1

2008-02-02

Torbjörn Sjöstrand , S. Mrenna , Peter Skands

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Review of Particle Physics

2010-07-01

K. Nakamura

This biennial Review summarizes much of particle physics. Using data from previous editions, plus 2158 new measurements from 551 papers, we list, evaluate, and average measured properties of gauge bosons, … This biennial Review summarizes much of particle physics. Using data from previous editions, plus 2158 new measurements from 551 papers, we list, evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We also summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as the Standard Model, particle detectors, probability, and statistics. Among the 108 reviews are many that are new or heavily revised including those on neutrino mass, mixing, and oscillations, QCD, top quark, CKM quark-mixing matrix, V ud & V us , V cb & V ub , fragmentation functions, particle detectors for accelerator and non-accelerator physics, magnetic monopoles, cosmological parameters, and big bang cosmology. A booklet is available containing the Summary Tables and abbreviated versions of some of the other sections of this full Review . All tables, listings, and reviews (and errata) are also available on the Particle Data Group website: pdg.lbl.gov .

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Neutrino Mass and Spontaneous Parity Nonconservation

1980-04-07

Rabindra N. Mohapatra , Goran Senjanović

In weak-interaction models with spontaneous parity nonconservation, based on the gauge group $\mathrm{SU}{(2)}_{L}\ensuremath{\bigotimes}\mathrm{SU}{(2)}_{R}\ensuremath{\bigotimes}\mathrm{U}(1)$, we obtain the following formula for the neutrino mass: ${m}_{{\ensuremath{\nu}}_{e}}\ensuremath{\simeq}\frac{{{m}_{e}}^{2}}{g{m}_{{W}_{R}}}$, where ${W}_{R}$ is the gauge boson which … In weak-interaction models with spontaneous parity nonconservation, based on the gauge group $\mathrm{SU}{(2)}_{L}\ensuremath{\bigotimes}\mathrm{SU}{(2)}_{R}\ensuremath{\bigotimes}\mathrm{U}(1)$, we obtain the following formula for the neutrino mass: ${m}_{{\ensuremath{\nu}}_{e}}\ensuremath{\simeq}\frac{{{m}_{e}}^{2}}{g{m}_{{W}_{R}}}$, where ${W}_{R}$ is the gauge boson which mediates right-handed weak interactions. This formula, valid for each lepton generation, relates the maximality of observed parity nonconservation at low energies to the smallness of neutrino masses.

Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC

2012-08-18

S. Chatrchyan , V. Khachatryan , A. M. Sirunyan +7 more

Results are presented from searches for the standard model Higgs boson in proton-proton collisions at sqrt(s) = 7 and 8 TeV in the Compact Muon Solenoid experiment at the LHC, … Results are presented from searches for the standard model Higgs boson in proton-proton collisions at sqrt(s) = 7 and 8 TeV in the Compact Muon Solenoid experiment at the LHC, using data samples corresponding to integrated luminosities of up to 5.1 inverse femtobarns at 7 TeV and 5.3 inverse femtobarns at 8 TeV. The search is performed in five decay modes: gamma gamma, ZZ, WW, tau tau, and b b-bar. An excess of events is observed above the expected background, with a local significance of 5.0 standard deviations, at a mass near 125 GeV, signalling the production of a new particle. The expected significance for a standard model Higgs boson of that mass is 5.8 standard deviations. The excess is most significant in the two decay modes with the best mass resolution, gamma gamma and ZZ; a fit to these signals gives a mass of 125.3 +/- 0.4 (stat.) +/- 0.5 (syst.) GeV. The decay to two photons indicates that the new particle is a boson with spin different from one.

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PYTHIA 6.4 physics and manual

2006-05-09

Torbjörn Sjöstrand , S. Mrenna , Peter Skands

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A schematic model of baryons and mesons

1964-02-01

Murray Gell‐Mann

Big-Bang Nucleosynthesis

2014-12-03

Brian D. Fields , P. Molaro , S. Sarkar

A critical review is given of the current status of cosmological nucleosynthesis. In the framework of the Standard Model with 3 types of relativistic neutrinos, the baryon-to-photon ratio, $\eta$, corresponding … A critical review is given of the current status of cosmological nucleosynthesis. In the framework of the Standard Model with 3 types of relativistic neutrinos, the baryon-to-photon ratio, $\eta$, corresponding to the inferred primordial abundances of deuterium and helium-4 is consistent with the independent determination of $\eta$ from observations of anisotropies in the cosmic microwave background. However the primordial abundance of lithium-7 inferred from observations is significantly below its expected value. Taking systematic uncertainties in the abundance estimates into account, there is overall concordance in the range $\eta = (5.7-6.7)\times 10^{-10}$ at 95% CL (corresponding to a cosmological baryon density $\Omega_B h^2 = 0.021 - 0.025$). The D and He-4 abundances, when combined with the CMB determination of $\eta$, provide the bound $N_\nu=3.28 \pm 0.28$ on the effective number of neutrino species. Other constraints on new physics are discussed briefly.

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New dimensions at a millimeter to a fermi and superstrings at a TeV

1998-09-01

Ignatios Antoniadis , Nima Arkani–Hamed , Savas Dimopoulos +1 more

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New Generation of Parton Distributions with Uncertainties from Global QCD Analysis

2002-07-04

J. Pumplin , D. Stump , J. Huston +3 more

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The anti-ktjet clustering algorithm

2008-04-16

Matteo Cacciari , Gavin P. Salam , Grégory Soyez

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FastJet user manual

2012-03-01

Matteo Cacciari , Gavin P. Salam , Grégory Soyez

FastJet is a C++ package that provides a broad range of jet finding and analysis tools. It includes efficient native implementations of all widely used 2-to-1 sequential recombination jet algorithms … FastJet is a C++ package that provides a broad range of jet finding and analysis tools. It includes efficient native implementations of all widely used 2-to-1 sequential recombination jet algorithms for pp and e+e- collisions, as well as access to 3rd party jet algorithms through a plugin mechanism, including all currently used cone algorithms. FastJet also provides means to facilitate the manipulation of jet substructure, including some common boosted heavy-object taggers, as well as tools for estimation of pileup and underlying-event noise levels, determination of jet areas and subtraction or suppression of noise in jets.

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Sensitivity of double deeply virtual Compton-scattering observables to generalized parton distributions

2025-06-24

J. S. Alvarado , M. Hoballah , E. Voutier | Physical review. C

Double deeply virtual Compton scattering (DDVCS) is a promising channel for generalized parton distribution (GPD) studies as it is a generalization of the deeply virtual Compton-scattering (DVCS) and timelike Compton-scattering … Double deeply virtual Compton scattering (DDVCS) is a promising channel for generalized parton distribution (GPD) studies as it is a generalization of the deeply virtual Compton-scattering (DVCS) and timelike Compton-scattering (TCS) processes. In contrast to DVCS and TCS, the GPD phase space accessed through DDVCS is not constrained by on-shell conditions on the incoming and outgoing photons, thus allowing unrestricted GPD extraction from experimental observables. Considering polarized electron and positron beams directed to a polarized proton target, we study the sensitivity of the DDVCS cross-section asymmetries to the chiral-even proton GPDs from different model predictions. The feasibility of such measurements is further investigated in the context of the CLAS and SoLID spectrometers at the Thomas Jefferson National Accelerator Facility and the future Electron-Ion Collider at the Brookhaven National Laboratory. Published by the American Physical Society 2025

Higgs trilinear coupling in the standard model effective field theory at the high luminosity LHC and the FCC-ee

2025-06-24

NULL AUTHOR_ID | Physical review. D/Physical review. D.

Vacuum polarization corrections to the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mi>μ</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>μ</mml:mi><mml:mo>−</mml:mo></mml:msup></mml:mrow></mml:math> spectrum

2025-06-23

NULL AUTHOR_ID | Physical review. D/Physical review. D.

The role and contribution of resonance effect for the decay process of $\bar B^{0}_s \rightarrow \pi^{+}\pi^{-}P$

2025-06-23

Xiliang 中国 Yuan , Chao Wang , Dorothy Li Bai +1 more | Chinese Physics C

Abstract The size of the direct CP asymmetry generated during the weak decay of hadrons is attributed to the weak phase and some strong phases. The weak phase comes from … Abstract The size of the direct CP asymmetry generated during the weak decay of hadrons is attributed to the weak phase and some strong phases. The weak phase comes from the CKM matrix and a strong phase may&#xD;result from the resonance effect which is produced by the mixing of vector meson $V\left\{\rho^{0}(770),\omega(782),\phi(1020)\right\}$ to $\pi^+ \pi^-$ meson pairs.&#xD;$\rho^{0}(770)$ can decay directly into $\pi^+ \pi^-$ meson pairs,&#xD;both $\omega(782)$ and $\phi(1020)$ can also decay into $\pi^+ \pi^-$ meson pairs with small contribution from isospin symmetry breaking. The main contribution for the middle state vector meson $\rho^{0}(770)-\omega(782)-\phi(1020)$ interference is the mix of $\rho^{0}(770)$, $\omega(782)-\rho^{0}(770)$ and $\phi(1020)-\rho^{0}(770)$.&#xD;We calculate the CP asymmetry and decay branching ratio for $\bar{B}^0_{s} \rightarrow \pi^+ \pi^- \pi^0 (\bar K ^{0})$ in the framework of QCD factorization and compare them with previous work. We also add the analysis of $\bar{B}^0_{s} \rightarrow \pi^+ \pi^- \eta(\eta^{(')})$ decay process.&#xD;The results show that the CP asymmetry of these four decay processes are significantly enhanced especially for the $\bar{B}^0_{s} \rightarrow \pi^+ \pi^- \bar K ^{0}$ decay process and the decay branching ratio also changes under resonance effect.&#xD;These work might provide support for the experimental analysis of the $\bar B^{0}_s$ meson. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Article funded by SCOAP3 and published under licence by Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Science and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.

Invisible decays of vector Charmonia and Bottomonia to determine the weak mixing angle at quarkonia scale

2025-06-23

G. Hernández-Tomé , C. S. Kim , G. López Castro | The European Physical Journal C

Abstract We compute the branching fractions of vector quarkonia ( $$V_Q=J/\psi , \psi ', \Upsilon (nS)$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>V</mml:mi> <mml:mi>Q</mml:mi> </mml:msub> <mml:mo>=</mml:mo> <mml:mi>J</mml:mi> <mml:mo>/</mml:mo> <mml:mi>ψ</mml:mi> <mml:mo>,</mml:mo> <mml:msup> <mml:mi>ψ</mml:mi> … Abstract We compute the branching fractions of vector quarkonia ( $$V_Q=J/\psi , \psi ', \Upsilon (nS)$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>V</mml:mi> <mml:mi>Q</mml:mi> </mml:msub> <mml:mo>=</mml:mo> <mml:mi>J</mml:mi> <mml:mo>/</mml:mo> <mml:mi>ψ</mml:mi> <mml:mo>,</mml:mo> <mml:msup> <mml:mi>ψ</mml:mi> <mml:mo>′</mml:mo> </mml:msup> <mml:mo>,</mml:mo> <mml:mi>Υ</mml:mi> <mml:mrow> <mml:mo>(</mml:mo> <mml:mi>n</mml:mi> <mml:mi>S</mml:mi> <mml:mo>)</mml:mo> </mml:mrow> </mml:mrow> </mml:math> ) decays into neutrino pairs, considering both Dirac and Majorana types, within the Standard Model (SM) and beyond. The vector nature of quarkonium states yields a decay width in the SM that depends upon the weak vector coupling of the heavy quark, offering the possibility to measure the weak mixing angle at the quarkonia mass scales. If neutrinos have non-standard neutral weak couplings, this could help to distinguish the nature of neutrinos in principle.

Search for new physics in final states with semivisible jets or anomalous signatures using the ATLAS detector

2025-06-23

NULL AUTHOR_ID | Physical review. D/Physical review. D.

Benchmarking nuclear matrix elements of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mn>0</mml:mn><mml:mi>ν</mml:mi><mml:mi>β</mml:mi><mml:mi>β</mml:mi></mml:mrow></mml:math> decay with high-energy nuclear collisions

2025-06-23

NULL AUTHOR_ID | Physical Review Letters

Production and characterisation of molybdenum/HOPG thin targets for the NUMEN experiment

2025-06-20

M. Fisichella , A. Massara , M. Giovannini +7 more | The European Physical Journal A

Bell inequality violation of light quarks in dihadron pair production at lepton colliders

2025-06-20

NULL AUTHOR_ID | Physical Review Letters

‘Fat-brane’ universal extra dimension model confronted with the ATLAS multi-jet and photonic searches at 13 TeV LHC

2025-06-20

Esra Akyumuk , Durmuş Karabacak | The European Physical Journal C

Abstract The current status of ‘fat-brane’ minimal Universal Extra Dimension (fat-mUED) is studied in light of recent results reported by the ATLAS experiment. At the Large Hadron Collider (LHC), color … Abstract The current status of ‘fat-brane’ minimal Universal Extra Dimension (fat-mUED) is studied in light of recent results reported by the ATLAS experiment. At the Large Hadron Collider (LHC), color charged first-level Kaluza–Klein (KK) particles (first-level excited quarks and gluons) can be abundantly pair-produced due to conserved quantity, viz., KK-parity, and the strong interaction. The cascade decay of these particles to one or more Standard Model (SM) particle(s) and lighter first-level KK particle(s) stops after producing the lightest excited massive state, named as the lightest KK particle (LKP). In the presence of gravity induced decays, the stability of the LKP is lost, allowing it to decay to photon or Z-boson by radiating KK-excited gravitons, leading to final states with photon(s) at the LHC. A variant signal topology emerges when pair-produced first-level colored KK particles undergo direct decay to their associated SM partners together with KK-excitations of gravitons resulting in a signature characterized by two hard jets and substantial missing energy. The ATLAS experiment lately reported two relevant searches at the 13 TeV LHC with 139 inverse-femtobarn of data: (i) multi-jet, and (ii) photon and jets accompanied by missing energy. Neither search observed substantial deviations from SM background expectations. Provided the absence of any number of excess events in both searches, we constrained parameters of the fat-mUED model, viz., the higher-dimensional Planck mass and the compactification scale.

Weak mixing angle under U(1, 3) colored gravity

2025-06-20

Robert Monjo | Journal of High Energy Physics

A bstract Colored gravity, based on U(1, 3) symmetry, emerges naturally in the complexification of Lorentzian manifolds and integrates U(1) electromagnetism as a subcase. This work explores the viability of … A bstract Colored gravity, based on U(1, 3) symmetry, emerges naturally in the complexification of Lorentzian manifolds and integrates U(1) electromagnetism as a subcase. This work explores the viability of also including strong and electroweak interactions under the U(1, 3) gauge group of colored gravity. We identify specific generators linked to leptonic and quark interactions and embed the standard Higgs mechanism. Crucially, the weak mixing angle (sin 2 θ W ) is predicted to exhibit about ~ 0 . 231 for lepton-lepton interactions (close to observations) and ~ 0 . 222 for hadron-lepton interactions, which is in 3 σ tension with some observations. These findings open pathways for reconciling experimental data with colored gravity and suggest avenues for quantum correction studies.

Sensitivity to triple Higgs couplings via di-Higgs production in the RxSM at the (HL-)LHC and future e+e− colliders

2025-06-20

F. Arco , S. Heinemeyer , Margarete Muehlleitner +3 more | Journal of High Energy Physics

A bstract The real Higgs singlet extension of the Standard Model (SM) without Z 2 symmetry, the RxSM, is the simplest extension of the SM that features a First Order … A bstract The real Higgs singlet extension of the Standard Model (SM) without Z 2 symmetry, the RxSM, is the simplest extension of the SM that features a First Order Electroweak Phase Transition (FOEWPT) in the early universe. The FOEWPT is one of the requirements needed for electroweak baryogenesis to explain the baryon asymmetry of the universe (BAU). Thus, the RxSM is a perfect example to study features related to the FOEWPT at current and future collider experiments. The RxSM has two $$ \mathcal{CP} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>CP</mml:mi> </mml:math> -even Higgs bosons, h and H , with masses m h < m H , where we assume that h corresponds to the Higgs boson discovered at the LHC. Our analysis is based on a benchmark plane that ensures the occurence of a strong FOEWPT, where m H > 2 m h is found. In a first step we analyze the di-Higgs production at the (HL-)LHC, gg → hh , with a focus on the impact of the trilinear Higgs couplings (THCs), λ hhh and λ hhH . The interferences of the resonant H -exchange diagram involving λ hhH and the non-resonant diagrams result in a characteristic peak-dip (or dip-peak) structure in the m hh distribution. We analyze how λ hhH can be accessed, taking into account the experimental smearing and binning. We also demonstrate that the approximation used by ATLAS and CMS for the resonant di-Higgs searches may fail to capture the relevant effects and lead to erroneous results. In a second step we analyze the benchmark plane at a future high-energy e + e − collider with $$ \sqrt{s} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> </mml:math> = 1000 GeV (ILC1000). We analyze the potential sensitivity to λ hhH via an experimental determination at the ILC1000 and demonstrate that it is nearly independent of the heavy Higgs-boson mass, as long as it is kinematically accessible.

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Fits of αs from event-shapes in the three-jet region: extension to all energies

2025-06-20

Paolo Nason , Giulia Zanderighi | Journal of High Energy Physics

A bstract This work is an extension of a previous publication [1] where we fitted the strong coupling α s together with the non-perturbative parameter α 0 from event-shape and … A bstract This work is an extension of a previous publication [1] where we fitted the strong coupling α s together with the non-perturbative parameter α 0 from event-shape and jet-shape distributions using power corrections computed in the three-jet region. In ref. [1] only ALEPH data at the Z -pole were used in the fit. Here, instead, we include a large data sample from various e + e − experiments at energies ranging from 22 to 207 GeV and revisited the treatment of theoretical uncertainties. We find that the inclusion of different energies, while not changing the central fit result considerably, helps to disentangle the dependence of perturbative and non-perturbative corrections. Our best fit result is α s ( M Z ) = $$ {0.1181}_{-0.0005-0.0021}^{+0.0002+0.0018} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mn>0.1181</mml:mn> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>0.0005</mml:mn> <mml:mo>−</mml:mo> <mml:mn>0.0021</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>0.0002</mml:mn> <mml:mo>+</mml:mo> <mml:mn>0.0018</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> , where the first error includes experimental uncertainties and the second one includes uncertainties associated with scale variation, mass effects, fit limits, non-perturbative schemes and non- perturbative uncertainties.

Leading qT/Q correction for Drell-Yan process in TMD factorization

2025-06-20

Arturo Arroyo-Castro , Ignazio Scimemi , Alexey Vladimirov | Journal of High Energy Physics

A bstract The transverse momentum dependent (TMD) factorization theorem accommodates various types of power corrections. Among them, the least studied are q T /Q corrections, which become significant at large … A bstract The transverse momentum dependent (TMD) factorization theorem accommodates various types of power corrections. Among them, the least studied are q T /Q corrections, which become significant at large values of transverse momentum. These corrections partially originate from higher-twist TMD distributions, which exhibit singularity at small transverse distances. We propose a decomposition that reveals this singularity explicitly, and makes the q T /Q correction manifest. As a concrete application, we consider the next-to-leading power correction for the angular distributions in Drell-Yan, and determine the leading q T /Q corrections. These corrections are significant for the angular distributions A 1 and A 3 , in complete agreement with the data.

Prospect for measurement of CP-violating observables in $$ {B}_s^0\to {D}_s^{\mp }{K}^{\pm } $$ decays at a future Z factory

2025-06-20

J. Peng , M. Zhao , X. Wang +3 more | Journal of High Energy Physics

A bstract A precise determination of the CKM angle γ from $$ {B}_s^0 $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>B</mml:mi> <mml:mi>s</mml:mi> <mml:mn>0</mml:mn> </mml:msubsup> </mml:math> oscillations in $$ {B}_s^0\to {D}_s^{\mp }{K}^{\pm } $$ … A bstract A precise determination of the CKM angle γ from $$ {B}_s^0 $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>B</mml:mi> <mml:mi>s</mml:mi> <mml:mn>0</mml:mn> </mml:msubsup> </mml:math> oscillations in $$ {B}_s^0\to {D}_s^{\mp }{K}^{\pm } $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>B</mml:mi> <mml:mi>s</mml:mi> <mml:mn>0</mml:mn> </mml:msubsup> <mml:mo>→</mml:mo> <mml:msubsup> <mml:mi>D</mml:mi> <mml:mi>s</mml:mi> <mml:mo>∓</mml:mo> </mml:msubsup> <mml:msup> <mml:mi>K</mml:mi> <mml:mo>±</mml:mo> </mml:msup> </mml:math> decays offers a critical test of the Standard Model and probes for new physics. We present a comprehensive study on the prospects of measuring γ at a future Tera- Z factory, utilizing the baseline detector concept of the Circular Electron Positron Collider (CEPC). A two-dimensional simultaneous fit framework, incorporating flavor tagging, decay time resolution modeling, and acceptance corrections, is developed using full Monte Carlo simulations of $$ {B}_s^0\to {D}_s^{\mp}\left(\to {K}^{\mp }{K}^{\pm }{\pi}^{\mp}\right){K}^{\pm } $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>B</mml:mi> <mml:mi>s</mml:mi> <mml:mn>0</mml:mn> </mml:msubsup> <mml:mo>→</mml:mo> <mml:msubsup> <mml:mi>D</mml:mi> <mml:mi>s</mml:mi> <mml:mo>∓</mml:mo> </mml:msubsup> <mml:mfenced> <mml:mrow> <mml:mo>→</mml:mo> <mml:msup> <mml:mi>K</mml:mi> <mml:mo>∓</mml:mo> </mml:msup> <mml:msup> <mml:mi>K</mml:mi> <mml:mo>±</mml:mo> </mml:msup> <mml:msup> <mml:mi>π</mml:mi> <mml:mo>∓</mml:mo> </mml:msup> </mml:mrow> </mml:mfenced> <mml:msup> <mml:mi>K</mml:mi> <mml:mo>±</mml:mo> </mml:msup> </mml:math> decays and inclusive background processes. The effective flavor tagging power reaches 23.6%, while the decay time resolution is determined to be 26 fs. Projecting to full statistics of signal events across three dominant $$ {D}_s^{-} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>D</mml:mi> <mml:mi>s</mml:mi> <mml:mo>−</mml:mo> </mml:msubsup> </mml:math> decay channels, we estimate a statistical precision of σ ( γ ) = 0 . 69 ° , which corresponds to 4.1 Tera- Z boson equivalent data. This study has established the feasibility of sub-degree level γ measurements at a Z factory, highlighting its unique advantages in time-dependent CP violation studies through ultra-precise vertexing and background suppression capabilities.

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Extending evolution mapping to massive neutrinos with COMET

2025-06-20

NULL AUTHOR_ID | Physical review. D/Physical review. D.

Evidence of doubly OZI-suppressed decay <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mi>η</mml:mi><mml:mi>c</mml:mi></mml:msub><mml:mo>→</mml:mo><mml:mi>ω</mml:mi><mml:mi>ϕ</mml:mi></mml:mrow></mml:math> in the radiative decay <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>J</mml:mi><mml:mi>/</mml:mi><mml:mi>ψ</mml:mi><mml:mo>→</mml:mo><mml:mi>γ</mml:mi><mml:msub><mml:mi>η</mml:mi><mml:mi>c</mml:…

2025-06-20

NULL AUTHOR_ID | Physical review. D/Physical review. D.

Dark showers from sneaky dark matter

2025-06-19

Adrián Carmona , Fatemeh Elahi , Christiane Scherb +1 more | Journal of High Energy Physics

A bstract We present a minimal composite dark matter model, based on a SU( N d ) dark sector with n f dark quarks and a heavy t-channel mediator. For … A bstract We present a minimal composite dark matter model, based on a SU( N d ) dark sector with n f dark quarks and a heavy t-channel mediator. For n f ≥ 4, the dark flavor symmetry guarantees the stability of a subset of the dark pions, which serve as our dark matter candidates. Their relic abundance is determined by dark sector annihilation with the remaining dark pions, which are unstable and decay. Due to their degenerate masses, the annihilation cross section is suppressed at low temperatures, thereby avoiding stringent constraints from indirect detection and opening up the GeV mass window. The decaying dark pions are naturally long lived. We obtain limits on the model from semi-visible or emerging jet searches and estimate the reach of future probes.

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Double parton distributions of the proton from basis light-front quantization

2025-06-19

NULL AUTHOR_ID | Physical review. D/Physical review. D.

Measurements of branching fractions of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mi>D</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>K</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:mn>3</mml:mn><mml:msup><mml:mi>π</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:mn>2</mml:mn><mml:msup><mml:mi>π</mml:mi><mml:mo>−</mml:mo></mml:msup></mml:mrow></mml:math> , <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="…

2025-06-19

NULL AUTHOR_ID | Physical review. D/Physical review. D.

Response simulation and primary vertex reconstruction in the SPD NICA straw tracker

2025-06-19

S. D. Morozova , A. V. Shipilova | Vestnik of Samara University Natural Science Series

In this work we investigate the temporal structure of the events in the spin physics detector (SPD) straw tracker at the JINR NICA. Using the Geant4 toolkit we simulate the … In this work we investigate the temporal structure of the events in the spin physics detector (SPD) straw tracker at the JINR NICA. Using the Geant4 toolkit we simulate the response of the straw layers sensitive elements in the triggerfree regime of SPD. Using the simulation results we present a simple algorithm for the fast primary-vertex finding and estimate the efficiency and purity of the reconstruction.

Off-shell vertices in heavy particle effective theories and B → Dπℓν

2025-06-19

Michele Papucci , Ryan Plestid | Journal of High Energy Physics

A bstract We study the modifications to decay amplitudes in heavy to heavy semileptonic decays with multiple hadrons in the final state due to intermediate heavy hadrons being off-shell or … A bstract We study the modifications to decay amplitudes in heavy to heavy semileptonic decays with multiple hadrons in the final state due to intermediate heavy hadrons being off-shell or having a finite width. Combining Heavy Hadron Chiral Perturbation Theory (HH χ PT) with a BCFW on-shell factorization formula, we show that these effects induce $$ \mathcal{O} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>O</mml:mi> </mml:math> (1/ M ) corrections to the standard results computed in the narrow-width approximation and therefore are important in extracting form factors from data. A combination of perturbative unitarity, analyticity, and reparameterization invariance fully determine these corrections in terms of known Isgur-Wise functions without the need to introduce new form factors. In doing so, we develop a novel technique to compute the boundary term at complex infinity in the BCFW formula for theories with derivatively coupled scalars. While we have used the $$ \overline{B} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mover> <mml:mi>B</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> → Dπℓν decay as an example, these techniques can generally be applied to effective field theories with (multiple) distinct reference vectors.

Displaced searches for Axion-Like Particles and Heavy Neutral Leptons at Mu3e

2025-06-19

Simon Knapen , Toby Opferkuch , Diego Redigolo +1 more | Journal of High Energy Physics

A bstract We present strategies for the Mu3e experiment to search for light, weakly coupled particles produced in rare muon decays, focusing on displaced e + e − decays within … A bstract We present strategies for the Mu3e experiment to search for light, weakly coupled particles produced in rare muon decays, focusing on displaced e + e − decays within the hollow target. In most scenarios the backgrounds can be fully suppressed with a suitable set of cuts. We furthermore quantify the interplay between displaced and prompt searches at Mu3e and existing constraints, showing how Mu3e has a unique opportunity to probe unexplored parameter space.

A simplified model of Heavy Vector Singlets for the LHC and future colliders

2025-06-19

Michael J. Baker , Timothy Martonhelyi , Andrea Thamm +1 more | Journal of High Energy Physics

A bstract We study a simplified model of two colourless heavy vector resonances in the singlet representation of SU(2) L , with zero and unit hypercharge. We discuss mixing with … A bstract We study a simplified model of two colourless heavy vector resonances in the singlet representation of SU(2) L , with zero and unit hypercharge. We discuss mixing with the Standard Model gauge bosons due to electroweak symmetry breaking, semi-analytic formulae for production at proton colliders, requirements to obey the narrow width approximation and selected low energy constraints. We show current LHC constraints and sensitivity projections for the HL-LHC, HE-LHC, SPPC and FCC-hh on the charged and neutral heavy vectors. The utility of the simplified model Lagrangian is demonstrated by matching these results onto three explicit models: a weakly coupled abelian extension of the Standard Model gauge group, a weakly coupled non-abelian extension and a strongly coupled minimal composite Higgs model. All our results are presented in terms of physical resonance masses, using expressions which are accurate even at vector masses near the electroweak scale due to a parameter inversion we derive. We discuss the importance of this inversion and point out that its effect, and the effects of electroweak symmetry breaking, can remain important up to resonance masses of several TeV. Finally, we clarify the relation between this simplified model and the Heavy Vector Triplet (HVT) model, a simplified model for heavy SU(2) L triplets with zero hypercharge, and provide exact and approximate matching relations.

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Improved measurement of absolute branching fraction of the inclusive decay $$ {\Lambda}_c^{+}\to {K}_S^0X $$

2025-06-19

M. Ablikim , M. N. Achasov , P. Adlarson +7 more | Journal of High Energy Physics

A bstract By analyzing 4.5 fb − 1 of e + e − collision data accumulated with the BESIII detector at center-of-mass energies ranging from 4599.53 MeV to 4698.82 MeV, … A bstract By analyzing 4.5 fb − 1 of e + e − collision data accumulated with the BESIII detector at center-of-mass energies ranging from 4599.53 MeV to 4698.82 MeV, we report the measurement of the absolute branching fraction (BF) of the inclusive decay $$ {\Lambda}_c^{+}\to {K}_S^0X $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>Λ</mml:mi> <mml:mi>c</mml:mi> <mml:mo>+</mml:mo> </mml:msubsup> <mml:mo>→</mml:mo> <mml:msubsup> <mml:mi>K</mml:mi> <mml:mi>S</mml:mi> <mml:mn>0</mml:mn> </mml:msubsup> <mml:mi>X</mml:mi> </mml:math> using the double-tag technique. The result is $$ \mathcal{B}\left({\Lambda}_c^{+}\to {K}_S^0X\right) $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>B</mml:mi> <mml:mfenced> <mml:mrow> <mml:msubsup> <mml:mi>Λ</mml:mi> <mml:mi>c</mml:mi> <mml:mo>+</mml:mo> </mml:msubsup> <mml:mo>→</mml:mo> <mml:msubsup> <mml:mi>K</mml:mi> <mml:mi>S</mml:mi> <mml:mn>0</mml:mn> </mml:msubsup> <mml:mi>X</mml:mi> </mml:mrow> </mml:mfenced> </mml:math> = (10.9 ± 0.2 ± 0.1)%, where the first uncertainty is statistical and the second is systematic. This result indicates that there are still undiscovered decay channels containing $$ {K}_S^0 $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>K</mml:mi> <mml:mi>S</mml:mi> <mml:mn>0</mml:mn> </mml:msubsup> </mml:math> in the final state with a combined BF of (3.0 ± 0.4)%. The BF of the inclusive decay $$ {\Lambda}_c^{+}\to {\overline{K}}^0/{K}^0X $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>Λ</mml:mi> <mml:mi>c</mml:mi> <mml:mo>+</mml:mo> </mml:msubsup> <mml:mo>→</mml:mo> <mml:msup> <mml:mover> <mml:mi>K</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> <mml:mn>0</mml:mn> </mml:msup> <mml:mo>/</mml:mo> <mml:msup> <mml:mi>K</mml:mi> <mml:mn>0</mml:mn> </mml:msup> <mml:mi>X</mml:mi> </mml:math> is calculated to be $$ \mathcal{B}\left({\Lambda}_c^{+}\to {\overline{K}}^0/{K}^0X\right) $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>B</mml:mi> <mml:mfenced> <mml:mrow> <mml:msubsup> <mml:mi>Λ</mml:mi> <mml:mi>c</mml:mi> <mml:mo>+</mml:mo> </mml:msubsup> <mml:mo>→</mml:mo> <mml:msup> <mml:mover> <mml:mi>K</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> <mml:mn>0</mml:mn> </mml:msup> <mml:mo>/</mml:mo> <mml:msup> <mml:mi>K</mml:mi> <mml:mn>0</mml:mn> </mml:msup> <mml:mi>X</mml:mi> </mml:mrow> </mml:mfenced> </mml:math> = (21.8 ± 0.4 ± 0.2)%, The result is in agreement with the prediction of the statistical isospin model.

Collinear and TMD distributions with dynamical soft-gluon resolution scale

2025-06-19

F. Hautmann , Lissa Keersmaekers , A. Lelek +2 more | Journal of High Energy Physics

A bstract Soft-gluon resolution scales characterize parton branching Monte Carlo implementations of the evolution equations for parton distribution functions in Quantum Chromodynamics (QCD). We examine scenarios with dynamical, i.e., branching-scale … A bstract Soft-gluon resolution scales characterize parton branching Monte Carlo implementations of the evolution equations for parton distribution functions in Quantum Chromodynamics (QCD). We examine scenarios with dynamical, i.e., branching-scale dependent, resolution scale, and discuss physical implications for both collinear and transverse-momentum dependent (TMD) distributions. We perform the first determination of parton distributions with dynamical resolution scale, at next-to-leading order (NLO) in perturbation theory, from fits to precision deep-inelastic scattering measurements from HERA. We present an application of TMD distributions with dynamical resolution scale to Drell-Yan lepton-pair transverse momentum spectra at the LHC and lower-energy experiments, and comment on the extraction of non-perturbative intrinsic- k T parameters from Drell-Yan data at small transverse momenta.

Threshold resummation for semi-inclusive single-hadron production with effective field theory

2025-06-18

Zhen Xu , Hua Xing Zhu | Journal of High Energy Physics

A bstract Large double-logarithmic corrections are induced by soft gluon emissions near threshold in the semi-inclusive e + e − annihilation (SIA) distributions, and must be resummed to all-orders in … A bstract Large double-logarithmic corrections are induced by soft gluon emissions near threshold in the semi-inclusive e + e − annihilation (SIA) distributions, and must be resummed to all-orders in perturbation theory for reliable theoretical predictions. Building on strategy developed for threshold resummation for DIS structure function in momentum space using soft-collinear effective theory (SCET), we present the explicit formalism for SIA cross section. We then perform the resummation directly in momentum space for γ ∗ → $$ q\overline{q} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>q</mml:mi> <mml:mover> <mml:mi>q</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> , H → gg and $$ H\to b\overline{b} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>H</mml:mi> <mml:mo>→</mml:mo> <mml:mi>b</mml:mi> <mml:mover> <mml:mi>b</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> to N 4 LL accuracy and demonstrate good convergence. We anticipate that these results will benefit the extraction of the light-quark, the heavy-quark as well as the gluon fragmentation functions.

Quark masses and mixing in string-inspired models

2025-06-18

Andrei Constantin , Cristofero S. Fraser‐Taliente , Thomas R. Harvey +2 more | Journal of High Energy Physics

A bstract We study a class of supersymmetric Froggatt-Nielsen (FN) models with multiple U(1) symmetries and Standard Model (SM) singlets inspired by heterotic string compactifications on Calabi-Yau threefolds. The string-theoretic … A bstract We study a class of supersymmetric Froggatt-Nielsen (FN) models with multiple U(1) symmetries and Standard Model (SM) singlets inspired by heterotic string compactifications on Calabi-Yau threefolds. The string-theoretic origin imposes a particular charge pattern on the SM fields and FN singlets, dividing the latter into perturbative and non-perturbative types. Employing systematic and heuristic search strategies, such as genetic algorithms, we identify charge assignments and singlet VEVs that replicate the observed mass and mixing hierarchies in the quark sector, and subsequently refine the Yukawa matrix coefficients to accurately match the observed values for the Higgs VEV, the quark and charged lepton masses and the CKM matrix. This bottom-up approach complements top-down string constructions and our results demonstrate that string FN models possess a sufficiently rich structure to account for flavour physics. On the other hand, the limited number of distinct viable charge patterns identified here indicates that flavour physics imposes tight constraints on string theory models, adding new constraints on particle spectra that are essential for achieving a realistic phenomenology.

Top-quark spin correlations as a tool to distinguish pseudoscalar A → ZH and scalar H → ZA signatures in $$ Zt\overline{t} $$ final states at the LHC

2025-06-18

F. Arco , Thomas Biekötter , Panagiotis Stylianou +1 more | Journal of High Energy Physics

A bstract Both ATLAS and CMS have recently performed the first searches for a heavy new spin-0 resonance decaying into a lighter new spin-0 resonance and a Z boson, where … A bstract Both ATLAS and CMS have recently performed the first searches for a heavy new spin-0 resonance decaying into a lighter new spin-0 resonance and a Z boson, where the lighter spin-0 resonance subsequently decays into $$ t\overline{t} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>t</mml:mi> <mml:mover> <mml:mi>t</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> pairs. These searches are of particular interest to probe Two Higgs doublet model (2HDM) parameter space regions that predict a strong first-order electroweak phase transition. In the absence of CP violation, the investigated decay is possible if the lighter and the heavier spin-0 particles have opposite CP parities. The analysis techniques employed by ATLAS and CMS do not distinguish between the two possible signatures A → ZH and H → ZA , where A and H denote CP-odd and CP-even Higgs bosons, respectively, if both signals are predicted to have the same total cross sections. We demonstrate the capability of angular variables that are sensitive to spin correlations of the top quarks to differentiate between A → ZH and H → ZA decays, even in scenarios where both signals possess identical total cross sections. Focusing on masses of 600 GeV and 800 GeV as a representative 2HDM benchmark, we find that a distinction between the two possible channels is possible with high significance with the anticipated data from the high-luminosity LHC, if the invariant mass distribution of the $$ t\overline{t} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>t</mml:mi> <mml:mover> <mml:mi>t</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> system is further binned in angular variables defined by the direction of flight of the leptons produced in the top-quark decays. Moreover, we find a moderate gain in experimental sensitivity due to the improved background rejection for both signals.

Markov chain Monte Carlo analysis to probe trilinear <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>R</mml:mi></mml:math> -parity violating SUSY scenarios and possible LHC signatures

2025-06-18

NULL AUTHOR_ID | Physical review. D/Physical review. D.

Nuclear and particle physics with cosmology volume 2

2025-06-18

B. Ishak | Contemporary Physics

J/$$\psi $$ and $$\Upsilon $$(1 S) production in jets at LHC energies

2025-06-17

L. Valencia Palomo | The European Physical Journal Plus

Testing lepton flavor universality at the Electron-Ion Collider

2025-06-17

Yunlai Deng , Xu-Hui Jiang , Tianbo Liu +1 more | Journal of High Energy Physics

A bstract Measurements of $$ b\to {c\tau}^{-}{\overline{\nu}}_{\tau } $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>b</mml:mi> <mml:mo>→</mml:mo> <mml:msup> <mml:mi>cτ</mml:mi> <mml:mo>−</mml:mo> </mml:msup> <mml:msub> <mml:mover> <mml:mi>ν</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> <mml:mi>τ</mml:mi> </mml:msub> </mml:math> transitions at colliders are highly … A bstract Measurements of $$ b\to {c\tau}^{-}{\overline{\nu}}_{\tau } $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>b</mml:mi> <mml:mo>→</mml:mo> <mml:msup> <mml:mi>cτ</mml:mi> <mml:mo>−</mml:mo> </mml:msup> <mml:msub> <mml:mover> <mml:mi>ν</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> <mml:mi>τ</mml:mi> </mml:msub> </mml:math> transitions at colliders are highly motivated for testing lepton flavor universality (LFU), a cornerstone hypothesis of the Standard Model (SM). Potential observations of LFU violation could provide significant evidence for physics beyond the SM (BSM). The substantial production of b -hadrons at the Electron-Ion Collider (EIC) would highlight its potential to support LFU testing and complement studies conducted at other experimental facilities. In this paper, we study the production of b -hadrons in deep inelastic scattering processes at the EIC with $$ \sqrt{s} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> </mml:math> = 100 GeV. We estimate the b -hadron yields at the EIC to reach $$ \mathcal{O}\left({10}^9\right) $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>O</mml:mi> <mml:mfenced> <mml:msup> <mml:mn>10</mml:mn> <mml:mn>9</mml:mn> </mml:msup> </mml:mfenced> </mml:math> with an integrated luminosity of up to 10 3 fb −1 . Furthermore, we perform a systematic study on various b -hadron decays, exploring the sensitivities of LFU-violating observables, including R J / ψ , $$ {R}_{D_s^{\left(\ast \right)}} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>R</mml:mi> <mml:msubsup> <mml:mi>D</mml:mi> <mml:mi>s</mml:mi> <mml:mfenced> <mml:mo>∗</mml:mo> </mml:mfenced> </mml:msubsup> </mml:msub> </mml:math> and $$ {R}_{\Lambda_c} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>R</mml:mi> <mml:msub> <mml:mi>Λ</mml:mi> <mml:mi>c</mml:mi> </mml:msub> </mml:msub> </mml:math> . Detailed strategies for track-based event reconstruction are investigated for these observables. We also include a discussion of the annihilation process $$ {B}_c^{+}\to {\tau}^{+}{\nu}_{\tau } $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>B</mml:mi> <mml:mi>c</mml:mi> <mml:mo>+</mml:mo> </mml:msubsup> <mml:mo>→</mml:mo> <mml:msup> <mml:mi>τ</mml:mi> <mml:mo>+</mml:mo> </mml:msup> <mml:msub> <mml:mi>ν</mml:mi> <mml:mi>τ</mml:mi> </mml:msub> </mml:math> . Finally, we provide a theoretical interpretation of the projected sensitivities within the framework of low energy effective field theory (LEFT). Our analysis indicates that the EIC has the potential to constrain the relevant Wilson coefficients at $$ \mathcal{O}(0.1) $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>O</mml:mi> <mml:mfenced> <mml:mn>0.1</mml:mn> </mml:mfenced> </mml:math> , offering complementary insights to other measurements.

Spatial distribution of the large-scale structure: An unsupervised search for parity violation

2025-06-17

Samuel Hewson , Will Handley , C. G. Lester | Physical review. D/Physical review. D.

We use machine learning methods to search for parity violations in the large-scale structure (LSS) of the Universe, motivated by recent claims of chirality detection using the 4-point correlation function … We use machine learning methods to search for parity violations in the large-scale structure (LSS) of the Universe, motivated by recent claims of chirality detection using the 4-point correlation function (4PCF), which would suggest new physics during the epoch of inflation. This work seeks to reproduce these claims using methods originating from high energy collider analyses. Our machine learning methods optimize some underlying parity odd function of the data, and use it to evaluate the parity odd fraction. We demonstrate the effectiveness and suitability of these methods and then apply them to the Baryon Oscillation Spectroscopic Survey (BOSS) catalog. No strong evidence for parity violation is detected. Published by the American Physical Society 2025

Aspen Open Jets: Unlocking LHC Data for Foundation Models in Particle Physics

2025-06-17

O. Amram , Luca Anzalone , Joschka Birk +7 more | Machine Learning Science and Technology

Abstract Foundation models are deep learning models pre-trained on large amounts of data which are&#xD;capable of generalizing to multiple datasets and/or downstream tasks. This work demonstrates how&#xD;data collected by the … Abstract Foundation models are deep learning models pre-trained on large amounts of data which are&#xD;capable of generalizing to multiple datasets and/or downstream tasks. This work demonstrates how&#xD;data collected by the CMS experiment at the Large Hadron Collider can be useful in pre-training&#xD;foundation models for HEP. Specifically, we introduce the AspenOpenJets dataset, consisting of&#xD;approximately 180M high pT jets derived from CMS 2016 Open Data. We show how pre-training&#xD;the OmniJet-α foundation model on AspenOpenJets improves performance on generative tasks&#xD;with significant domain shift: generating boosted top and QCD jets from the simulated JetClass&#xD;dataset. In addition to demonstrating the power of pre-training of a jet-based foundation model on&#xD;actual proton-proton collision data, we provide the ML-ready derived AspenOpenJets dataset for&#xD;further public use.

Region analysis of H → γγ via a bottom quark loop

2025-06-17

Jinzhao Hou , Jian Wang , D. Zhang | Journal of High Energy Physics

A bstract The H → γγ decay is an ideal process to study the structure of next-to-leading power logarithms induced by quarks due to its simple initial and final states. … A bstract The H → γγ decay is an ideal process to study the structure of next-to-leading power logarithms induced by quarks due to its simple initial and final states. We perform a region analysis of this process up to two-loop level to inspect the origins of the logarithms. To deal with the endpoint singularities that are prevalent for the next-to-leading power logarithms, we have adopted two different kinds of regulators to exhibit the advantages and disadvantages of each regulator. In the analytic regulator we have chosen, the power of the propagator is changed by η . And the endpoint singularities are regulated in the form of 1/ η . These poles cancel between the collinear and anti-collinear sectors since there is no soft mode in such a regulator. In the ∆ regulator, the soft sector is important. The leading and next-to-leading logarithms can be inferred from only this sector. Moreover, the symmetry between the collinear and anti-collinear sectors is preserved. After imposing a cut on the bottom quark transverse momentum, the leading order result is finite in each sector. We also discuss the next-to-next-to-leading power contributions and find that the potential factorization formulae involve two-dimensional endpoint singularities. Our region analysis could help to develop sophisticated factorization and resummation schemes beyond leading power.

Electron EDM and Γ(μ → eγ) in the 2HDM

2025-06-17

Wolfgang Altmannshofer , Benoît Assi , Joachim Brod +4 more | Journal of High Energy Physics

A bstract We present the first complete two-loop calculation of the electric dipole moment of the electron, as well as the rates of the lepton-flavor violating decays μ → e … A bstract We present the first complete two-loop calculation of the electric dipole moment of the electron, as well as the rates of the lepton-flavor violating decays μ → e + γ and τ → e/μ + γ , in the unconstrained two-Higgs doublet model. We include the most general Yukawa interactions of the Higgs doublets with the Standard Model fermions up to quadratic order, and allow for generic phases in the Higgs potential. A python implementation of our results is provided via a public git repository.

Search for heavy neutral resonances decaying to tau lepton pairs in proton-proton collisions at <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msqrt><mml:mrow><mml:mi>s</mml:mi></mml:mrow></mml:msqrt><mml:mo>=</mml:mo><mml:mn>13</mml:mn><mml:mtext> </mml:mtext><mml:mtext> </mml:mtext><mml:mi>TeV</mml:mi></mml:mrow></mml:math>

2025-06-16

Aram Hayrapetyan , A. Tumasyan , W. Adam +7 more | Physical review. D/Physical review. D.

A search for heavy neutral gauge bosons (<a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:msup><a:mrow><a:mi>Z</a:mi></a:mrow><a:mrow><a:mo>′</a:mo></a:mrow></a:msup></a:mrow></a:math>) decaying into a pair of tau leptons is performed in proton-proton collisions at <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:msqrt><c:mi>s</c:mi></c:msqrt><c:mo>=</c:mo><c:mn>13</c:mn><c:mtext> </c:mtext><c:mtext> </c:mtext><c:mi>TeV</c:mi></c:math> at the … A search for heavy neutral gauge bosons (<a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:msup><a:mrow><a:mi>Z</a:mi></a:mrow><a:mrow><a:mo>′</a:mo></a:mrow></a:msup></a:mrow></a:math>) decaying into a pair of tau leptons is performed in proton-proton collisions at <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:msqrt><c:mi>s</c:mi></c:msqrt><c:mo>=</c:mo><c:mn>13</c:mn><c:mtext> </c:mtext><c:mtext> </c:mtext><c:mi>TeV</c:mi></c:math> at the CERN LHC. The data were collected with the CMS detector and correspond to an integrated luminosity of <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:mn>138</e:mn><e:mtext> </e:mtext><e:mtext> </e:mtext><e:msup><e:mi>fb</e:mi><e:mrow><e:mo>−</e:mo><e:mn>1</e:mn></e:mrow></e:msup></e:math>. The observations are found to be in agreement with the expectation from standard model processes. Limits at 95% confidence level are set on the product of the <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" display="inline"><g:mrow><g:msup><g:mrow><g:mi>Z</g:mi></g:mrow><g:mrow><g:mo>′</g:mo></g:mrow></g:msup></g:mrow></g:math> production cross section and its branching fraction to tau lepton pairs for a range of <i:math xmlns:i="http://www.w3.org/1998/Math/MathML" display="inline"><i:mrow><i:msup><i:mrow><i:mi>Z</i:mi></i:mrow><i:mrow><i:mo>′</i:mo></i:mrow></i:msup></i:mrow></i:math> boson masses. For a narrow resonance in the sequential standard model scenario, a <k:math xmlns:k="http://www.w3.org/1998/Math/MathML" display="inline"><k:mrow><k:msup><k:mrow><k:mi>Z</k:mi></k:mrow><k:mrow><k:mo>′</k:mo></k:mrow></k:msup></k:mrow></k:math> boson with a mass below 3.5 TeV is excluded. This is the most stringent limit to date from this type of search. © 2025 CERN, for the CMS Collaboration 2025 CERN

Quark matter at four loops: Hardships and how to overcome them

2025-06-16

NULL AUTHOR_ID | Physical Review Letters

First measurement of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi>D</mml:mi></mml:mrow><mml:mrow><mml:mi>s</mml:mi><mml:mn>1</mml:mn></mml:mrow></mml:msub><mml:mo stretchy="false">(</mml:mo><mml:msup><mml:mrow><mml:mn>1</mml:mn></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msup><mml:mo stretchy="false">)</mml:mo><mml:mo stretchy="false">(</mml:mo><mml:mn>2536</mml:mn><mml:msup><mml:mrow><mml:mo stretchy="false">)</mml:…

2025-06-16

S. Acharya , A. Agarwal , G. Aglieri Rinella +7 more | Physical review. D/Physical review. D.

The production yields of the orbitally excited charm-strange mesons <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:msub><a:mrow><a:mi mathvariant="normal">D</a:mi></a:mrow><a:mrow><a:mi mathvariant="normal">s</a:mi><a:mn>1</a:mn></a:mrow></a:msub><a:mo stretchy="false">(</a:mo><a:msup><a:mrow><a:mn>1</a:mn></a:mrow><a:mrow><a:mo>+</a:mo></a:mrow></a:msup><a:mo stretchy="false">)</a:mo><a:mo stretchy="false">(</a:mo><a:mn>2536</a:mn><a:msup><a:mrow><a:mo stretchy="false">)</a:mo></a:mrow><a:mrow><a:mo>+</a:mo></a:mrow></a:msup></a:mrow></a:math> and <i:math xmlns:i="http://www.w3.org/1998/Math/MathML" display="inline"><i:msubsup><i:mi mathvariant="normal">D</i:mi><i:mrow><i:mi mathvariant="normal">s</i:mi><i:mn>2</i:mn></i:mrow><i:mo>*</i:mo></i:msubsup><i:mo stretchy="false">(</i:mo><i:msup><i:mn>2</i:mn><i:mo>+</i:mo></i:msup><i:mo stretchy="false">)</i:mo><i:mo stretchy="false">(</i:mo><i:mn>2573</i:mn><i:msup><i:mo stretchy="false">)</i:mo><i:mo>+</i:mo></i:msup></i:math> were measured … The production yields of the orbitally excited charm-strange mesons <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:msub><a:mrow><a:mi mathvariant="normal">D</a:mi></a:mrow><a:mrow><a:mi mathvariant="normal">s</a:mi><a:mn>1</a:mn></a:mrow></a:msub><a:mo stretchy="false">(</a:mo><a:msup><a:mrow><a:mn>1</a:mn></a:mrow><a:mrow><a:mo>+</a:mo></a:mrow></a:msup><a:mo stretchy="false">)</a:mo><a:mo stretchy="false">(</a:mo><a:mn>2536</a:mn><a:msup><a:mrow><a:mo stretchy="false">)</a:mo></a:mrow><a:mrow><a:mo>+</a:mo></a:mrow></a:msup></a:mrow></a:math> and <i:math xmlns:i="http://www.w3.org/1998/Math/MathML" display="inline"><i:msubsup><i:mi mathvariant="normal">D</i:mi><i:mrow><i:mi mathvariant="normal">s</i:mi><i:mn>2</i:mn></i:mrow><i:mo>*</i:mo></i:msubsup><i:mo stretchy="false">(</i:mo><i:msup><i:mn>2</i:mn><i:mo>+</i:mo></i:msup><i:mo stretchy="false">)</i:mo><i:mo stretchy="false">(</i:mo><i:mn>2573</i:mn><i:msup><i:mo stretchy="false">)</i:mo><i:mo>+</i:mo></i:msup></i:math> were measured for the first time in proton-proton (pp) collisions at a center-of-mass energy of <q:math xmlns:q="http://www.w3.org/1998/Math/MathML" display="inline"><q:msqrt><q:mi>s</q:mi></q:msqrt><q:mo>=</q:mo><q:mn>13</q:mn><q:mtext> </q:mtext><q:mtext> </q:mtext><q:mi>TeV</q:mi></q:math> with the ALICE experiment at the LHC. The <s:math xmlns:s="http://www.w3.org/1998/Math/MathML" display="inline"><s:msubsup><s:mi mathvariant="normal">D</s:mi><s:mrow><s:mi mathvariant="normal">s</s:mi><s:mn>1</s:mn></s:mrow><s:mo>+</s:mo></s:msubsup></s:math> and <w:math xmlns:w="http://www.w3.org/1998/Math/MathML" display="inline"><w:msubsup><w:mi mathvariant="normal">D</w:mi><w:mrow><w:mi mathvariant="normal">s</w:mi><w:mn>2</w:mn></w:mrow><w:mrow><w:mo>*</w:mo><w:mo>+</w:mo></w:mrow></w:msubsup></w:math> mesons were measured at midrapidity (<ab:math xmlns:ab="http://www.w3.org/1998/Math/MathML" display="inline"><ab:mo stretchy="false">|</ab:mo><ab:mi>y</ab:mi><ab:mo stretchy="false">|</ab:mo><ab:mo><</ab:mo><ab:mn>0.5</ab:mn></ab:math>) in minimum-bias and high-multiplicity pp collisions in the transverse-momentum interval <eb:math xmlns:eb="http://www.w3.org/1998/Math/MathML" display="inline"><eb:mrow><eb:mn>2</eb:mn><eb:mo><</eb:mo><eb:msub><eb:mrow><eb:mi>p</eb:mi></eb:mrow><eb:mrow><eb:mi mathvariant="normal">T</eb:mi></eb:mrow></eb:msub><eb:mo><</eb:mo><eb:mn>24</eb:mn><eb:mtext> </eb:mtext><eb:mtext> </eb:mtext><eb:mrow><eb:mi>GeV</eb:mi><eb:mo>/</eb:mo><eb:mi>c</eb:mi></eb:mrow></eb:mrow></eb:math>. Their production yields relative to the <hb:math xmlns:hb="http://www.w3.org/1998/Math/MathML" display="inline"><hb:msubsup><hb:mi mathvariant="normal">D</hb:mi><hb:mi mathvariant="normal">s</hb:mi><hb:mo>+</hb:mo></hb:msubsup></hb:math> ground-state yield were found to be compatible between minimum-bias and high-multiplicity collisions, as well as with previous measurements in <lb:math xmlns:lb="http://www.w3.org/1998/Math/MathML" display="inline"><lb:msup><lb:mi mathvariant="normal">e</lb:mi><lb:mo>±</lb:mo></lb:msup><lb:mi mathvariant="normal">p</lb:mi></lb:math> and <pb:math xmlns:pb="http://www.w3.org/1998/Math/MathML" display="inline"><pb:msup><pb:mi mathvariant="normal">e</pb:mi><pb:mo>+</pb:mo></pb:msup><pb:msup><pb:mi mathvariant="normal">e</pb:mi><pb:mo>−</pb:mo></pb:msup></pb:math> collisions. The measured <tb:math xmlns:tb="http://www.w3.org/1998/Math/MathML" display="inline"><tb:msubsup><tb:mi mathvariant="normal">D</tb:mi><tb:mrow><tb:mi mathvariant="normal">s</tb:mi><tb:mn>1</tb:mn></tb:mrow><tb:mo>+</tb:mo></tb:msubsup><tb:mo>/</tb:mo><tb:msubsup><tb:mi mathvariant="normal">D</tb:mi><tb:mi mathvariant="normal">s</tb:mi><tb:mo>+</tb:mo></tb:msubsup></tb:math> and <zb:math xmlns:zb="http://www.w3.org/1998/Math/MathML" display="inline"><zb:msubsup><zb:mi mathvariant="normal">D</zb:mi><zb:mrow><zb:mi mathvariant="normal">s</zb:mi><zb:mn>2</zb:mn></zb:mrow><zb:mrow><zb:mo>*</zb:mo><zb:mo>+</zb:mo></zb:mrow></zb:msubsup><zb:mo>/</zb:mo><zb:msubsup><zb:mi mathvariant="normal">D</zb:mi><zb:mi mathvariant="normal">s</zb:mi><zb:mo>+</zb:mo></zb:msubsup></zb:math> yield ratios are described by statistical hadronization models and can be used to tune the parameters governing the production of excited charm-strange hadrons in Monte Carlo generators, such as 8. © 2025 CERN, for the ALICE Collaboration 2025 CERN

Exploring the exclusive decay <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mi>B</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:mi>ω</mml:mi><mml:msup><mml:mi>ℓ</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:mi>ν</mml:mi></mml:mrow></mml:math> with light-cone sum rules

2025-06-15

NULL AUTHOR_ID | Physical review. D/Physical review. D.

Lepton number violating and conserving heavy baryon four-body decays in the presence of two almost degenerat heavy neutrinos

2025-06-14

NULL AUTHOR_ID | Physical review. D/Physical review. D.

Yüksek Enerjili Büyük Hadron Çarpıştırıcısı Bazlı Müon-Proton Çarpıştırıcılarında Uyarılmış Müon Üretimi

2025-06-14

M. Ö. Sahin , A. Caliskan | Karadeniz Fen Bilimleri Dergisi

Bu çalışmada uyarılmış müonların Yüksek Enerjili Büyük Hadron Çarpıştırıcısı (YE-BHÇ) bazlı müon proton çarpıştırıcılarında temas etkileşim yöntemiyle üretilip ayar etkileşimleri ile foton kanalına bozunmasıyla oluşan uyarılmış müon sinyal süreci (µp … Bu çalışmada uyarılmış müonların Yüksek Enerjili Büyük Hadron Çarpıştırıcısı (YE-BHÇ) bazlı müon proton çarpıştırıcılarında temas etkileşim yöntemiyle üretilip ayar etkileşimleri ile foton kanalına bozunmasıyla oluşan uyarılmış müon sinyal süreci (µp → µ*j → µγj) incelenmiştir. Uyarılmış müonun sinyalini ardalandan ayırmak için keşif sınırlamaları uygulanarak sinyal-ardalan analizi yapılmıştır. Farklı kompozitlik skalası değerleri için yapılan hesaplamalar sonucunda uyarılmış müon kütlesine ait keşif (5σ), gözlem (3σ) ve dışarlama (2σ) limitleri belirlenmiştir. Kütle merkezi enerjileri 9 ve 12,7 TeV olan bu çarpıştırıcıların uyarılmış müon araştırmalarında iyi bir potansiyele sahip olacağı sonucuna ulaşılmıştır.

Improved sensitivity in the search for rare decays of Gd isotopes

2025-06-14

B. Lehnert , S. Nagorny , M. D. Thiesse +5 more | The European Physical Journal C

Abstract Gadolinium is widely used in multiple low-background experiments, making its isotopes accessible for rare decay searches both in-situ and through radiopurity screening data. This study presents an improved search … Abstract Gadolinium is widely used in multiple low-background experiments, making its isotopes accessible for rare decay searches both in-situ and through radiopurity screening data. This study presents an improved search for rare alpha and double-beta decay modes in $$^{152}\hbox {Gd}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mmultiscripts> <mml:mrow/> <mml:mrow/> <mml:mn>152</mml:mn> </mml:mmultiscripts> <mml:mtext>Gd</mml:mtext> </mml:mrow> </mml:math> , $$^{154}\hbox {Gd}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mmultiscripts> <mml:mrow/> <mml:mrow/> <mml:mn>154</mml:mn> </mml:mmultiscripts> <mml:mtext>Gd</mml:mtext> </mml:mrow> </mml:math> , and $$^{160}\hbox {Gd}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mmultiscripts> <mml:mrow/> <mml:mrow/> <mml:mn>160</mml:mn> </mml:mmultiscripts> <mml:mtext>Gd</mml:mtext> </mml:mrow> </mml:math> isotopes using ultra-low background HPGe detectors at the Boulby Underground Screening (BUGS) facility. A total exposure of 6.7 $$\hbox {kg}\cdot \hbox {years}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mtext>kg</mml:mtext> <mml:mo>·</mml:mo> <mml:mtext>years</mml:mtext> </mml:mrow> </mml:math> of natural gadolinium was achieved using gadolinium sulfate octahydrate $$(\text {Gd}_2(\text {SO}_4)_3 \cdot 8\text {H}_2\text {O})$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mo>(</mml:mo> <mml:msub> <mml:mtext>Gd</mml:mtext> <mml:mn>2</mml:mn> </mml:msub> <mml:msub> <mml:mrow> <mml:mo>(</mml:mo> <mml:msub> <mml:mtext>SO</mml:mtext> <mml:mn>4</mml:mn> </mml:msub> <mml:mo>)</mml:mo> </mml:mrow> <mml:mn>3</mml:mn> </mml:msub> <mml:mo>·</mml:mo> <mml:mn>8</mml:mn> <mml:msub> <mml:mtext>H</mml:mtext> <mml:mn>2</mml:mn> </mml:msub> <mml:mtext>O</mml:mtext> <mml:mo>)</mml:mo> </mml:mrow> </mml:math> samples, originally screened for radiopurity prior to their deployment in the Super-Kamiokande neutrino experiment. Due to the detection methodology, only decays into excited states accompanied by gamma-ray emission were accessible. A Bayesian analysis incorporating prior experimental results was employed, leading to new lower half-life limits in the range of $$10^{19} - 10^{21}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msup> <mml:mn>10</mml:mn> <mml:mn>19</mml:mn> </mml:msup> <mml:mo>-</mml:mo> <mml:msup> <mml:mn>10</mml:mn> <mml:mn>21</mml:mn> </mml:msup> </mml:mrow> </mml:math> years - an improvement of approximately two orders of magnitude over previous constraints. No statistically significant decay signals were observed. These results demonstrate the effectiveness of repurposing large-scale radiopurity screening campaigns for fundamental physics research.

Generative Unfolding with Distribution Mapping

2024-11-08

Anja Butter , Sascha Diefenbacher , Nathan Huetsch +4 more

Machine learning enables unbinned, highly-differential cross section measurements. A recent idea uses generative models to morph a starting simulation into the unfolded data. We show how to extend two morphing … Machine learning enables unbinned, highly-differential cross section measurements. A recent idea uses generative models to morph a starting simulation into the unfolded data. We show how to extend two morphing techniques, Schr\"odinger Bridges and Direct Diffusion, in order to ensure that the models learn the correct conditional probabilities. This brings distribution mapping to a similar level of accuracy as the state-of-the-art conditional generative unfolding methods. Numerical results are presented with a standard benchmark dataset of single jet substructure as well as for a new dataset describing a 22-dimensional phase space of Z + 2-jets.

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Exploring the Flavor Symmetry Landscape

2024-03-05

Alfredo Glioti , Riccardo Rattazzi , Lorenzo Ricci +1 more

We explore flavor dynamics in the broad scenario of a strongly interacting light Higgs (SILH). Our study focuses on the mechanism of partial fermion compositeness, but is otherwise as systematic … We explore flavor dynamics in the broad scenario of a strongly interacting light Higgs (SILH). Our study focuses on the mechanism of partial fermion compositeness, but is otherwise as systematic as possible. Concretely, we classify the options for the underlying flavor (and CP) symmetries, which are necessary in order to bring this scenario safely within the range of present and future explorations. Our main goal in this context is to provide a practical map between the space of hypotheses (the models) and the experimental ground that will be explored in the medium and long term, in both indirect and direct searches, in practice at HL-LHC and Belle II, in EDM searches and eventually at FCC-hh. Our study encompasses scenarios with the maximal possible flavor symmetry, corresponding to minimal flavor violation (MFV), scenarios with no symmetry, corresponding to the so-called flavor anarchy, and various intermediate cases that complete the picture. One main result is that the scenarios that allow for the lowest new physics scale have intermediate flavor symmetry rather than the maximal symmetry of MFV models. Such optimal models are rather resilient to indirect exploration via flavor and CP violating observables, and can only be satisfactorily explored at a future high-energy collider. On the other hand, the next two decades of indirect exploration will significantly stress the parameter space of a large swat of less optimal but more generic models up to mass scales competing with those of the FCC-hh.

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