Search for composite and exotic fermions at LEP 2
The DELPHI Collaboration
P. Abreu21 - et al.
LIP, IST, FCUL - Av. Elias Garcia, 14-1o, P-1000 Lisboa Codex, Portugal
Received: 30 October 1998 / Published online: 1 March 1999
A search for unstable heavy fermions with the DELPHI detector at LEP is reported. Sequential and non-canonical leptons, as well as excited leptons and quarks, are considered. The data analysed correspond to an integrated luminosity of about 48pb-1 at an centre-of-mass energy of 183GeV and about 20pb-1 equally shared between the centre-of-mass energies of 172GeV and 161GeV. The search for pair-produced new leptons establishes 95% confidence level mass limits in the region between 70GeV/c2 and 90GeV/c2, depending on the channel. The search for singly produced excited leptons and quarks establishes upper limits on the ratio of the coupling of the excited fermion to its mass ()as a function of the mass.