1992/09/09 by E. Nardi, Enrico Nardi · 1 citation
Physics and Astronomy · #Dark Matter and Cosmic Phenomena #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #hep-ph
paper · pdf · doi:10.1103/physrevd.48.1240
published as Phys.Rev. D48 (1993) 1240-1247 · plain tex, 22 pages + 2 pages figures in PostScript (appended after `\bye'), UM-TH 92-19
arxiv created 1992/09/09 · openalex publication_date 1993/08/01 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We study a new class of flavor-changing interactions, which can arise in models based on extended gauge groups (rank >4) when new charged fermions are present together with a new neutral gauge boson. We discuss the cases in which the flavor-changing couplings in the new neutral current coupled to the Z^\ensuremath' are theoretically expected to be large, implying that the observed suppression of neutral flavor-changing transitions must be provided by heavy Z^\ensuremath' masses together with small Z\ensuremath-Z^\ensuremath' mixing angles. Concentrating on E6 models, we show how the tight experimental limit on \ensuremathμ\ensuremath→eee implies serious constraints on the Z^\ensuremath' mass and mixing angle. We conclude that if the value of the flavor-changing parameters is assumed to lie in a theoretically natural range, in most cases the presence of a Z^\ensuremath' much lighter than 1 TeV is unlikely.