Type: Article
Publication Date: 2017-05-02
Citations: 11
DOI: https://doi.org/10.1103/physrevd.95.092002
We report the first measurement of the fraction of $J/\ensuremath{\psi}$ mesons coming from $B$-meson decay (${F}_{B\ensuremath{\rightarrow}J/\ensuremath{\psi}}$) in $p+p$ collisions at $\sqrt{s}=510\text{ }\text{ }\mathrm{GeV}$. The measurement is performed using the forward silicon vertex detector and central vertex detector at PHENIX, which provide precise tracking and distance-of-closest-approach determinations, enabling the statistical separation of $J/\ensuremath{\psi}$ due to $B$-meson decays from prompt $J/\ensuremath{\psi}$. The measured value of ${F}_{B\ensuremath{\rightarrow}J/\ensuremath{\psi}}$ is $8.1%\ifmmode\pm\else\textpm\fi{}2.3%(\text{stat})\ifmmode\pm\else\textpm\fi{}1.9%(\text{syst})$ for $J/\ensuremath{\psi}$ with transverse momenta $0<{p}_{T}<5\text{ }\text{ }\mathrm{GeV}/c$ and rapidity $1.2<|y|<2.2$. The measured fraction ${F}_{B\ensuremath{\rightarrow}J/\ensuremath{\psi}}$ at PHENIX is compared to values measured by other experiments at higher center of mass energies and to fixed-order-next-to-leading-logarithm and color-evaporation-model predictions. The $b\overline{b}$ cross section per unit rapidity [$d\ensuremath{\sigma}/dy(pp\ensuremath{\rightarrow}b\overline{b})$] extracted from the obtained ${F}_{B\ensuremath{\rightarrow}J/\ensuremath{\psi}}$ and the PHENIX inclusive $J/\ensuremath{\psi}$ cross section measured at 200 GeV scaled with color-evaporation-model calculations, at the mean $B$ hadron rapidity $y=\ifmmode\pm\else\textpm\fi{}1.7$ in 510 GeV $p+p$ collisions, is $3.6{3}_{\ensuremath{-}1.70}^{+1.92}\text{ }\text{ }\ensuremath{\mu}\mathrm{b}$. It is consistent with the fixed-order-next-to-leading-logarithm calculations.