DOI 10.1007/s100529901068
Probing the exotic particle content beyond the standard model
E. Ma1 - M. Raidal2 - U. Sarkar2,3
1 Department of Physics, University of California,
Riverside, California 92521, USA
2 Theory Group, DESY, D-22603 Hamburg, Germany
3 Physical Research Laboratory, Ahmedabad 380 009, India
Received: 1 September 1998 / Revised version: 15 October 1998 / Published online: 22 March 1999
Abstract
We explore the possible exotic particle content beyond the standard model by
examining all its scalar bilinear combinations. We categorize these exotic
scalar fields and show that without the suppression of (A) their Yukawa
couplings with the known quarks and leptons, and (B) the trilinear couplings
among themselves, most are already constrained to be very heavy from the
nonobservation of proton decay and neutron-antineutron oscillations, the
smallness of ,
and
mixing, as well as the requirement of a nonzero baryon
asymmetry of the universe. On the other hand, assumption (B) may be naturally
violated in many models, especially in supersymmetry, hence certain exotic
scalars are allowed to be below a few TeV in mass and would be easily
detectable at planned future hadron colliders. In particular, large cross
sections for the distinctive processes like
and
would be expected at the Fermilab Tevatron and CERN LHC,
respectively.
Copyright Springer-Verlag