New bounds on leptoquarks
New bounds on leptoquarks
We derive new bounds on scalar leptoquark couplings from ${\mathit{K}}^{0}$-K${\mathrm{\ifmmode\bar\else\textasciimacron\fi{}}}^{0}$, ${\mathit{D}}^{0}$-D${\mathrm{\ifmmode\bar\else\textasciimacron\fi{}}}^{0}$, and ${\mathit{B}}^{0}$-B${\mathrm{\ifmmode\bar\else\textasciimacron\fi{}}}^{0}$ mixing. Although leptoquarks contribute to these processes only at one loop, their contribution is large, due to the lack of Glashow-Iliopoulos-Maiani cancelation. Our bounds have two important features: (i) They bound ${\mathit{g}}^{4}$/${\mathit{M}}^{2}$, in contrast to the hitherto …