DOI 10.1007/s100520000333
Stability of the lepton-flavor mixing matrix
against quantum corrections
1 Department of Physics, The Ohio State University,
Columbus, OH 43210, USA
Faculty of Engineering, Mie University,
Tsu Mie 514-8507, Japan
2 Theory Group, KEK, Tsukuba Ibaraki 305-0801, Japan
Received: 24 June 1999 / Revised version: 23 December 1999 /
Published online: 17 March 2000 - © Springer-Verlag 2000
Abstract
Recent neutrino experiments suggest strong evidence of
tiny neutrino masses and the lepton-flavor mixing.
Neutrino-oscillation solutions for
the atmospheric neutrino anomaly and the solar neutrino deficit
can determine the texture of the neutrino mass matrix
according to the neutrino mass hierarchies as
Type A:
,
Type B:
,
and
Type C:
,
where mi is the i-th generation neutrino mass.
In this paper we study the stability
of the lepton-flavor mixing matrix against quantum corrections
for all three types of mass hierarchy
in the minimal supersymmetric Standard Model
with an effective dimension-five operator which
gives the Majorana masses of neutrinos.
The relative sign assignments of neutrino masses in each type
play crucial role for the stability against
quantum corrections.
We find that the lepton-flavor mixing matrix of
Type A is stable against quantum corrections, and
that of Type B with the same (opposite)
signs of m1 and m2 are unstable (stable).
For Type C, the lepton-flavor-mixing
matrix approaches the definite unitary matrix according to the
relative sign assignments of the neutrino mass eigenvalues
as the effects of quantum corrections become
large enough to neglect the
squared mass differences of neutrinos.
Copyright Società Italiana di Fisica, Springer-Verlag 2000
