2023 Impact factor 4.2
Particles and Fields
Eur. Phys. J. C 8, 41-58
DOI 10.1007/s100529901074

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 $\rm e^+e^-$ 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 ($\lambda/m_{f^*}$)as a function of the mass.

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