Quantization of electric charge from anomaly constraints and a Majorana neutrino

Journal Article · Sun Dec 31 23:00:00 EST 1989 · Physical Review, D (Particles Fields); (USA)

DOI:https://doi.org/10.1103/PhysRevD.41.271· OSTI ID:6965271

Babu, K S; Mohapatra, R N ^[1]

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1. Department of Physics and Astronomy, University of Maryland, College Park, Maryland 20742 (US)

In gauge models of electroweak interactions where the gauge group contains an explicit U(1) factor contributing to U(1){sub em}, due to the arbitrariness of the U(1) quantum numbers, electric charge is not quantized. While requiring the cancellation of gauge and gravitational anomalies reduces the arbitrariness considerably, it is still not restrictive enough to fix all the quark and lepton charges. Analyzing a large class of gauge models that contain the right-handed neutrino {nu}{sub {ital R}}, we find that the anomaly constraints, together with the requirement of nonvanishing fermion masses, lead to charge quantization only if the neutrino is a Majorana particle. The basic reason for this is the appearance of a hidden anomaly-free local U(1){sub {ital B}{minus}{ital L}} symmetry in the Lagrangian, once {nu}{sub {ital R}} is included, leading to a one-parameter family of solutions to the anomaly constraints. The Majorana mass of the neutrino breaks this hidden local symmetry. We also show that this phenomenon of charge dequantization'' occurs in models without {nu}{sub {ital R}} due to the appearance of hidden anomaly-free horizontal U(1) symmetries. In these models, quantization of electric charge is restored by including Dirac mass terms that break the hidden symmetry. Our work provides a new way to understand charge quantization outside the framework of grand unified theories.

• OSTI ID: 6965271
• Journal Information: Physical Review, D (Particles Fields); (USA), Journal Name: Physical Review, D (Particles Fields); (USA) Vol. 41:1; ISSN PRVDA; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

645203* -- High Energy Physics-- Particle Interactions & Properties-Theoretical-- Weak Interactions & Properties
645300 -- High Energy Physics-- Particle Invariance Principles & Symmetries
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ELECTRIC CHARGES
ELEMENTARY PARTICLES
FERMIONS
FIELD THEORIES
GRAND UNIFIED THEORY
GRAVITATIONAL FIELDS
LEPTONS
LIE GROUPS
MAGNETIC MONOPOLES
MAJORANA THEORY
MASS
MASSLESS PARTICLES
MATHEMATICAL MODELS
MONOPOLES
NEUTRINOS
PARTICLE MODELS
POSTULATED PARTICLES
QUANTIZATION
QUANTUM NUMBERS
STANDARD MODEL
SYMMETRY BREAKING
SYMMETRY GROUPS
U GROUPS
U-1 GROUPS
UNIFIED GAUGE MODELS
UNIFIED-FIELD THEORIES
WEINBERG-SALAM GAUGE MODEL