Neutrino masses, mixing angles and the
of couplings in the MSSM
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
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