Search for charginos nearly mass-degenerate with the lightest neutralino |
| |
Authors: | P Abreu |
| |
Institution: | (1) LIP, IST, FCUL - Av. Elias Garcia, 14-1°, P-1000 Lisboa Codex, Portugal , PT |
| |
Abstract: | A search for charginos with masses close to the mass of the lightest neutralino is reported, based on the data collected
with the DELPHI detector at LEP from 1995 to 1997 at centre-of-mass energies between 130 and 183 GeV. The signature of a photon
at high transverse momentum radiated from the initial state reduces the two-photon background to acceptable rates, thus making
the mass differences between a few hundred MeV/c and 3 GeV/c detectable. In very nearly degenerate scenarios, the lifetime of the chargino can be large enough to produce either visible
secondary vertices or decays outside the detector; therefore, quasi-stable heavy charged particles and displaced decay vertices
were also searched for. No excess of events with respect to the Standard Model expectations was observed, and limits in the
plane of chargino-neutralino mass difference versus chargino mass are given.
Received: 20 March 1999 / Published online: 8 September 1999 |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|