Search for low-mass Leptoquarks using the bbτ+τ− final state in Pb-Pb ultra-peripheral collisions
Li-Gang Xia
Leptoquarks (LQ), coupling to the third generation of fermions, with mass less than 200 GeV are not explored before. We propose to search for low-mass LQs in Pb-Pb ultra-peripheral collisions. There are a couple of advantages:
1) high photon flux provides high production rates for low mass LQs;
2) the background contamination is much lower than that in p-p collisions.
Taking the scalar LQ, S3, coupling to b quark and τ lepton and with mass 50 GeV as example, the upper limit at 95% Confidence Level of the coupling constant, λ, is 0.063 if no events are observed based on a dataset of 1 fb−1 Pb-Pb ultra-peripheral collisions at 5.02 TeV and the analysis strategy presented here. This proposal is complementary to the searches using p-p collisions which are sensitive to high-mass LQs