Stability of the lepton-flavor mixing matrix against quantum corrections

Unitarity of the [Formula: see text] lepton flavor mixing matrix [Formula: see text] is unavoidably violated in a seesaw mechanism if its new heavy degrees of freedom are slightly mixed with the active neutrino flavors. We propose to use the atomic transition process [Formula: see text] (for [Formula: see text], [Formula: see text]), where [Formula: see text] and [Formula: see text] stand, respectively for the excited and ground levels of an atomic system, to probe or constrain the unitarity-violating effects of [Formula: see text]. We find that the photon spectrum of this transition will be distorted by the effects of [Formula: see text] and [Formula: see text] as compared with the [Formula: see text] case. We locate certain frequencies in the photon spectrum to minimize the degeneracy of effects of the unitarity violation and uncertainties of the flavor mixing parameters themselves. The requirements of a nominal experimental setup to test the unitarity of [Formula: see text] are briefly discussed.

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Can the lepton flavor mixing matrix be symmetric?

Physical Review D ◽

10.1103/physrevd.65.113010 ◽

2002 ◽

Vol 65 (11) ◽

Cited By ~ 14

Author(s):

Zhi-zhong Xing

Keyword(s):

Lepton Flavor ◽

Flavor Mixing ◽

Mixing Matrix

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IS Ue3 REALLY RELATED TO THE SOLAR NEUTRINO SOLUTIONS?

Modern Physics Letters A ◽

10.1142/s0217732300002838 ◽

2000 ◽

Vol 15 (37) ◽

pp. 2257-2263

Author(s):

N. HABA ◽

TOMOHARU SUZUKI

Keyword(s):

Physical Parameter ◽

Neutrino Oscillation ◽

Neutrino Mass ◽

Solar Neutrino ◽

Mass Matrix ◽

Majorana Neutrino ◽

Lepton Flavor ◽

Flavor Mixing ◽

Mixing Matrix ◽

Majorana Neutrino Mass

It is important to measure Ue3 in the lepton flavor mixing matrix in order to understand the structure of Majorana neutrino mass matrix. Recently it is conjectured that the measurement of Ue3 would discriminate one solution among various solar neutrino ones provided that the three mass eigenvalues of neutrinos have the relation m1≪m2≪m3 or m1~m2≪m3. In this letter we show that this conjecture is rather restrictive and the relation [Formula: see text] is derived by a nontrivial assumption and Ue3 cannot discriminate among solar neutrino oscillation solutions without the information on another physical parameter.

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NEUTRINO OSCILLATIONS AND LEPTON FLAVOR MIXING

Modern Physics Letters A ◽

10.1142/s0217732301005473 ◽

2001 ◽

Vol 16 (33) ◽

pp. 2169-2175 ◽

Cited By ~ 16

Author(s):

KYUNGSIK KANG ◽

SIN KYU KANG ◽

C. S. KIM ◽

SUN MYONG KIM

Keyword(s):

Neutrino Mass ◽

Mass Matrix ◽

Neutrino Masses ◽

Input Constraints ◽

Neutrino Mixing ◽

Lepton Flavor ◽

Invariance Violation ◽

The Family ◽

Flavor Mixing ◽

Mixing Matrix

In view of the recent announcement on nonzero neutrino mass from Super-Kamiokande experiment, it would be very timely to investigate all the possible scenarios on masses and mixings of light neutrinos. Recently suggested mass matrix texture for the quark CKM mixing, which can be originated from the family permutation symmetry and its suitable breakings, is assumed for the neutrino mass matrix and determined by the four combinations of solar, atmospheric and LSND neutrino data and cosmological hot dark matter bound as input constraints. The charged-lepton mass matrix is assumed to be diagonal so that the neutrino mixing matrix can be identified directly as the lepton flavor mixing matrix and no CP invariance violation originates from the leptonic sector. The results favor hierarchical patterns for the neutrino masses, which follow from the case when the solar-atmospheric data is used.

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