Search for supersymmetry with a dominant R-parity violating LQDbar couplings in e+e- collisions at centre-of-mass energies of 130GeV to 172 GeV

TL;DR

This paper reports a search for supersymmetric particles with R-parity violation via LQDbar couplings in e+e- collisions at energies of 130-172 GeV, setting new mass limits based on observed data.

Contribution

It provides the first experimental limits on supersymmetric particle masses assuming dominant R-parity violating LQDbar couplings at these energies.

Findings

No excess events observed beyond Standard Model expectations.

Charginos with masses below 81 GeV/c^2 are excluded at 95% CL.

Neutralinos with masses below 29 GeV/c^2 are excluded at 95% CL.

Abstract

A search for pair-production of supersymmetric particles under the assumption that R-parity is violated via a dominant LQDbar coupling has been performed using the data collected by ALEPH at centre-of-mass energies of 130-172 GeV. The observed candidate events in the data are in agreement with the Standard Model expectation. This result is translated into lower limits on the masses of charginos, neutralinos, sleptons, sneutrinos and squarks. For instance, for m_0=500 GeV/c^2 and tan(beta)=sqrt(2) charginos with masses smaller than 81 GeV/c^2 and neutralinos with masses smaller than 29 GeV/c^2 are excluded at the 95% confidence level for any generation structure of the LQDbar coupling.