Search for pair-produced leptoquarks in e+e- interactions at sqrt(s) = 183 GeV

TL;DR

This study searched for pair-produced leptoquarks in electron-positron collisions at 183 GeV but found no evidence, setting new lower mass limits and improving existing constraints especially for decays to quark-neutrino pairs.

Contribution

First search for leptoquark pair production at 183 GeV e+e- collisions with improved mass limits, particularly for large quark-neutrino decay branching ratios.

Findings

No evidence of leptoquark production was observed.

Established lower mass limits for scalar and vector leptoquarks.

Enhanced existing constraints in the large decay branching ratio region.

Abstract

A search for pair-produced leptoquarks has been performed using a sample of e+e- collision events collected by the OPAL detector at LEP at e+e- centre-of-mass energies of about 183 GeV. The data sample corresponds to an integrated luminosity of 55.9 pb-1. The leptoquarks were assumed to be produced via couplings to the photon and the Z0 and then to decay within a single fermion generation. No evidence for contributions from leptoquark pair production processes was observed. Lower limits on scalar and vector leptoquark masses are obtained. The existing limits are improved in the region of large decay branching ratio to quark-neutrino.