Models with natural seesaw mechanism for neutrino masses with identical parity- and SU(2) sub R -breaking scales

Journal Article · Mon Apr 01 00:00:00 EST 1991 · Physical Review, D (Particles Fields); (USA)

DOI:https://doi.org/10.1103/PhysRevD.43.2351· OSTI ID:5771444

Parida, M K; Patra, P K ^[1]; Hazra, C C ^[2]

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1. Physics Department, North-Eastern Hill University, Bijni Complex, Laitumkhrah, Shillong 793 003, India (IN)
2. Physics Department, Ravenshaw College, Cuttack 753 003, India (IN)

Chang and Mohapatra have observed that the implementation of the seesaw mechanism explaining small neutrino masses in left-right-symmetric or SO(10) models requires the parity- ({ital P}-) and SU(2){sub {ital R}}-breaking scales to be widely separated ({ital M}{sub {ital P}}{much gt}{ital M}{sub {ital R}}). In this paper we show how the mechanism operates naturally even though the two scales are identical. The gauge group immediately preceding the standard model emerges to be its minimal extension based upon SU(3){sub {ital C}}{times}SU(2){sub {ital L}}{times}U(1){sub {ital R}}{times}U(1){sub {ital B}{minus}{ital L}} with a second neutral {ital Z}{sub {ital R}}-boson mass {ital M}{sub {ital R}}{sup 0}{congruent}300--10{sup 5} GeV. An embedding in the partial unification scheme leads to observable rare kaon decays. In the two symmetry-breaking chains investigated in SO(10) with parity broken either at the unification scale ({ital M}{sub {ital P}}={ital M}{sub {ital U}}), or at an intermediate scale ({ital M}{sub {ital P}}{approx gt}10{sup 11} GeV), proton decay is predicted with lifetime near the observable limit; but, in the former case, rare kaon decays are also predicted near the observable limit when an intermediate gauge group SU(2){sub {ital L}}{times}U(1){sub {ital R}}{times}SU(4){sub {ital C}} survives down to the scale {ital M}{sub {ital C}}{congruent}10{sup 5} GeV provided sin{sup 2}{theta}{sub {ital W}}{congruent}0.24. The criterion for naturalness turns out to be wide separation between {ital P}- and U(1){sub {ital B}{minus}{ital L}}-breaking scales.

• OSTI ID: 5771444
• Journal Information: Physical Review, D (Particles Fields); (USA), Vol. 43:7; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
NEUTRINOS
MASS
PROTONS
DECAY
EIGENVALUES
GRAND UNIFIED THEORY
KAONS
LAGRANGIAN FUNCTION
LIFETIME
PARITY
QUARKS
STANDARD MODEL
SU-2 GROUPS
SU-3 GROUPS
SYMMETRY BREAKING
U-1 GROUPS
VACUUM STATES
BARYONS
BOSONS
ELEMENTARY PARTICLES
FERMIONS
FIELD THEORIES
FUNCTIONS
HADRONS
LEPTONS
LIE GROUPS
MASSLESS PARTICLES
MATHEMATICAL MODELS
MESONS
NUCLEONS
PARTICLE MODELS
PARTICLE PROPERTIES
POSTULATED PARTICLES
PSEUDOSCALAR MESONS
STRANGE MESONS
STRANGE PARTICLES
SU GROUPS
SYMMETRY GROUPS
U GROUPS
UNIFIED GAUGE MODELS
UNIFIED-FIELD THEORIES
645203* - High Energy Physics- Particle Interactions & Properties-Theoretical- Weak Interactions & Properties
645300 - High Energy Physics- Particle Invariance Principles & Symmetries