Journal article
Search for nearly mass-degenerate charginos and neutralinos at LEP: The OPAL collaboration
G Abbiendi, C Ainsley, PF Åkesson, G Alexander, J Allison, P Amaral, G Anagnostou, KJ Anderson, S Arcelli, S Asai, D Axen, G Azuelos, I Bailey, E Barberio, RJ Barlow, RJ Batley, P Bechtle, T Behnke, KW Bell, PJ Bell Show all
European Physical Journal C | Published : 2003
Abstract
A search was performed for charginos with masses close to the mass of the lightest neutralino in e+e- collisions at centre-of-mass energies of 189-209 GeV recorded by the OPAL detector at LEP. Events were selected if they had an observed high-energy photon from initial state radiation, reducing the dominant background from two-photon scattering to a negligible level. No significant excess over Standard Model expectations has been observed in the analysed data set corresponding to an integrated luminosity of 570 pb-1. Upper limits were derived on the chargino pair-production cross-section, and lower limits on the chargino mass were derived in the context of the Minimal Supersymmetric Extensio..
View full abstract