arXiv:hep-ph/0301268·v2·High Energy Physics — Phenomenology
Z-lineshape versus 4th generation masses
S. S. Bulanov🇷🇺 · V. A. Novikov🇷🇺 · L. B. Okun (ITEP, Moscow, Russia)🇷🇺 · A. N. Rozanov (CPPM, IN2P3, CNRS, Univ. Mediteranee, Marseilles, France and ITEP, Moscow, Russia)🇫🇷 · M. I. Vysotsky (ITEP, Moscow, Russia)🇷🇺
Abstract
The dependence of the Z-resonance shape on the location of the threshold of the N\bar{N} production (N is the 4th generation neutrino) is analyzed. The bounds on the existence of 4th generation are derived from the comparison of the theoretical expression for the Z-lineshape with the experimental data. The 4th generation is excluded at 95% C. L. for m_N<46.7\pm 0.2 GeV.
Comments: 17 pages, 5 figures, 1 table, LaTex; references added