Revisiting scalar leptoquark at the LHC

Abstract

We investigate the Standard Model (SM) extended with a colored charged scalar, leptoquark, having fractional electromagnetic charge $-1/3$. We mostly focus on the decays of the leptoquark into second and third generations via $c\,\mu, t\, \tau$ decay modes. We perform a PYTHIA-based simulation considering all the dominant SM backgrounds at the LHC with 14\,TeV center of mass energy. Limits have been calculated for the leptoquark mass that can be probed at the LHC with an integrated luminosity of 3000 fb$^{-1}$. The leptoquark mass, reconstructed from its decay products into the third generation, has the maximum reach. However, the $\mu + c$ channel, comprising a very hard muon and $c$-jet produces a much cleaner mass peak. Single leptoquark production in association with a $\mu$ or $\nu$ provides some unique signatures that can also be probed at the LHC.