Search for third-generation scalar leptoquarks in the tt channel in proton-proton collisions at √s=8 TeV

Abstract

A search for pair production of third-generation scalar leptoquarks decaying to top quark and t lepton pairs is presented using proton-proton collision data at a center-of-mass energy of vs=8 TeV collected with the CMS detector at the LHC and corresponding to an integrated luminosity of 19.7 fb-1. The search is performed using events that contain an electron or a muon, a hadronically decaying t lepton, and two or more jets. The observations are found to be consistent with the standard model predictions. Assuming that all leptoquarks decay to a top quark and a t lepton, the existence of pair produced, charge -1/3, third-generation leptoquarks up to a mass of 685 GeV is excluded at 95% confidence level. This result constitutes the first direct limit for leptoquarks decaying into a top quark and a t lepton, and may also be applied directly to the pair production of bottom squarks decaying predominantly via the R-parity violating coupling λ′333.