Probing leptoquark chirality via top polarization at Colliders

Dr. Joydeep Roy (Hosted by Dev), ITP, Beijing

Anomalies in recent LHCb, Belle and Babar measurements of RD(*) , and RK(*) in B decays may indicate the new physics beyond the Standard Model (SM). The leptoquarks (LQ) that couple to the 3rd generation quarks and leptons have been proposed as a viable new physics (NP) explanation. Such left-handed LQs can couple to both bottom and top quarks. Therefore we studied the pair-production of a vector, chiral leptoquark followed by the decay chain . Such processes suffer from the SM background signicantly. Since top particles decay before the hadronization, it is possible to reconstruct chirality of boosted top quarks and consequently the chirality of top coupling to the LQs. We perform analysis on the top quark's chirality in such production channel of the LQ, which can be purely left-handed in comparison to unpolarized SM background. In order to discriminate signal from background, we used two very powerful discriminators for such events, the b energy ratio E(b)/E(t) and the missing transverse energy (MET) cut. We studied the prospects of distinguishing the chirality of a potential LQ signal for the high luminosity run of the LHC and also in other future collider such as FCC-hh.