Search for pair production of second generation scalar leptoquarks

TL;DR

This paper reports a search for second generation scalar leptoquarks in proton-antiproton collisions at 1.96 TeV, setting mass limits based on decay modes, with no evidence of their existence found.

Contribution

It provides the first experimental limits on second generation scalar leptoquark masses at the Tevatron energy scale, based on 1.0 fb-1 of data.

Findings

Excluded scalar leptoquarks with masses up to 316 GeV for beta=1.

Excluded scalar leptoquarks with masses up to 270 GeV for beta=0.5.

No excess over the standard model prediction observed.

Abstract

We report on a search for the pair production of second generation scalar leptoquarks (LQ) in ppbar collisions at the center of mass energy sqrt(s)=1.96 TeV using a data set corresponding to an integrated luminosity of 1.0 fb-1 collected with the D0 experiment at the Fermilab Tevatron Collider. Topologies arising from the LQLQbar->muqnuq and LQLQbar->muqmuq decay modes are investigated. No excess of data over the standard model prediction is observed and upper limits on the leptoquark pair production cross section are derived at the 95% C.L. as a function of the leptoquark mass and the branching fraction beta for the decay LQ->muq. These are interpreted as lower limits on the leptoquark mass as a function of beta. For beta=1 (0.5), scalar second generation leptoquarks with masses up to 316 GeV (270 GeV) are excluded.