Limits on the Masses of Supersymmetric Particles at sqrt(s)=189 GeV

TL;DR

This paper reports new lower mass limits for supersymmetric particles based on LEP2 data at 189 GeV, assuming R-parity conservation within the MSSM framework, with limits valid across a range of parameters.

Contribution

It provides the first comprehensive set of lower mass bounds for multiple supersymmetric particles at LEP2 energies, independent of certain MSSM parameters.

Findings

Lightest neutralino heavier than 32.3 GeV/c^2

Charginos and other particles have mass limits above 60 GeV/c^2

Limits are valid for 1 ≤ tan(beta) ≤ 40 and do not depend on m_0 or M_2

Abstract

Searches for charginos, neutralinos and sleptons at LEP2 centre-of-mass energies from 130 GeV to 189 GeV have been used to set lower limits on the mass of the Lightest Supersymmetric Particle and other supersymmetric particles within the MSSM framework. R-parity conservation has been assumed. The lightest neutralino was found to be heavier than 32.3 GeV/c^2 independent of the m_0 value. The lightest chargino, the second-to-lightest neutralino, the next-to-heaviest neutralino, the heaviest neutralino, the sneutrino and the right-handed selectron were found to be heavier than 62.4 GeV/c^2, 62.4 GeV/c^2, 99.9 GeV/c^2, 116.0 GeV/c^2, 61.0 GeV/c^2, and 87.0 GeV/c^2, respectively. These limits do not depend on m_0 or M_2 and are valid for 1 \leq tan(beta) \leq 40, in the mu region where the lightest neutralino is the LSP. If the sneutrino is heavier than the chargino the lightest neutralino has to be heavier than 32.4 GeV/c^2. The effects of mixings in the third family of sfermions on these limits are discussed. The confidence level of all limits given is 95%.