Bounds on second generation scalar leptoquarks from the anomalous magnetic moment of the muon

Abstract

We calculate the contribution of second generation scalar leptoquarks to the anomalous magnetic moment of the muon. The coupling ${\ensuremath{\lambda}}_{\mathrm{\ensuremath{\Phi}}\mathit{L}}$ between the leptoquarks, the quarks, and the leptons is taken to be of the order of the electroweak coupling ${\mathit{g}}_{2}$. In the near future, the E-821 Collaboration at Brookhaven will reduce the experimental error on this parameter to \ensuremath{\Delta}${\mathit{a}}_{\mathrm{\ensuremath{\mu}}}^{\mathrm{expt}}$4\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}10}$, an improvement of 20 over its current value. Combining this error with the current uncertainty on the hadronic contribution to g-2 we obtain a bound of ${\mathit{m}}_{\mathrm{\ensuremath{\Phi}}\mathit{L}}$>88 GeV for the second generation scalar leptoquark while we get ${\mathit{m}}_{\mathrm{\ensuremath{\Phi}}\mathit{L}}$>186 GeV when neglecting the hadronic uncertainty. \textcopyright{} 1995 The American Physical Society.