DOI 10.1007/s100529900262
Neutrino masses, mixing angles and the
unification
of couplings in the MSSM
M. Carena1 - J. Ellis1 - S. Lola1 - C.E.M. Wagner1,2
1 Theory Division, CERN, 1211 Geneva, Switzerland
2 Argonne National Laboratory, 9700 Cass Ave., Argonne, IL 60439,
USA
Received: 22 June 1999 / Published online: 10 December 1999
Abstract
In the light of the gathering evidence for
neutrino oscillations, coming in particular from
the Super-Kamiokande data on atmospheric neutrinos,
we re-analyze the unification
of gauge and Yukawa couplings within the minimal supersymmetric
extension of the Standard Model (MSSM).
Guided by a range of different grand-unified models, we stress
the relevance of large mixing in the lepton sector for the question
of bottom-tau Yukawa coupling unification.
We also discuss the dependence of the favoured value of 
on
the characteristics of the high-energy quark and lepton mass matrices.
In particular, we find that, in the presence
of large lepton mixing, Yukawa unification
can be achieved for intermediate values of
that were
previously disfavoured. The renormalization-group sensitivity to the
structures of different mass matrices may enable Yukawa
unification to serve as a useful probe of GUT models.
Copyright Springer-Verlag 2000
