Author/Authors :
OPAL Collaboration، نويسنده , , K Ackerstaff، نويسنده , , G Alexander، نويسنده , , J Allison، نويسنده , , N. Altekamp، نويسنده , , K. Ametewee، نويسنده , , K.J. Anderson، نويسنده , , S Anderson، نويسنده , , S Arcelli، نويسنده , , S Asai، نويسنده , , D Axen، نويسنده , , G Azuelos، نويسنده , , A.H. Ball، نويسنده , , E Barberio، نويسنده , , R.J. Barlow، نويسنده , , R. Bartoldus، نويسنده , , J.R. Batley، نويسنده , , J Bechtluft، نويسنده , , C Beeston، نويسنده , , T Behnke، نويسنده , , et al.، نويسنده ,
Abstract :
Charginos and neutralinos, predicted by supersymmetric theories, have been searched for in e+e− collisions with an intergrated luminosity of 10.0 pb−1 at a centre-of-mass energy of s = 161 GeV with the OPAL detector at LEP. Two candidate events are selected; consistent with the total background estimate of 0.7 ± 0.2 events. The 95% C.L. lower limit on the lightest chargino mass in the Minimal Supersymmetric Standard Model is 78.5 GeV if the universal scalar mass m0 is greater than 1 TeV, and 62.0 GeV for the smallest m0 compatible with slepton and sneutrino mass limits obtained at centre-of-mass energies near the Z peak. These limits were obtained under the conditions that the lightest chargino is heavier than the lightest neutralino by more than 10 GeV and tan β = 1.5. The new exclusion limits significantly improve on the results obtained at s = 130 and 136 GeV.
