Cosmological baryon and lepton number in the presence of electroweak fermion-number violation

Journal Article · Thu Nov 15 04:00:00 EST 1990 · Physical Review, D (Particles Fields); (USA)

DOI:https://doi.org/10.1103/PhysRevD.42.3344· OSTI ID:6101388

Harvey, J A ^[1]; Turner, M S ^[2]

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1. Department of Physics, Enrico Fermi Institute, The University of Chicago, Chicago, IL (USA)
2. Department of Physics, Enrico Fermi Institute, The University of Chicago, Chicago, IL (USA) Department of Astronomy Astrophysics, The University of Chicago, Chicago, IL (USA) NASA/Fermilab Astrophysics Center, Fermi National Accelerator Laboratory, Batavia, IL (USA)

In the presence of rapid fermion-number violation due to nonperturbative electroweak effects certain relations between the baryon number of the Universe and the lepton numbers of the Universe are predicted. In some cases the electron-neutrino asymmetry is exactly specified in terms of the baryon asymmetry. Without introducing new particles--beyond the usual quarks and leptons--it is necessary that the Universe possess a nonzero value of {ital B}{minus}{ital L} prior to the epoch of fermion-number violation if baryon and lepton asymmetries are to survive. Contrary to intuition, even though electroweak processes violate {ital B}+{ital L}, a nonzero value of {ital B}+{ital L} persists after the epoch of rapid fermion-number violation. If the standard model is extended to include lepton-number violation, for example, through Majorana neutrino masses, then electroweak processes will reduce the baryon number to zero even in the presence of an initial {ital B}{minus}{ital L} unless 20{ital M}{sub {ital L}}{approx gt} {radical}({ital T}{sub {ital B}{minus}{ital L}}{ital m}{sub Pl}) where {ital M}{sub {ital L}} sets the scale of lepton-number violation and {ital T}{sub {ital B}{minus}{ital L}} is the temperature at which a {ital B}{minus}{ital L} asymmetry is produced. In some models this implies that neutrinos must be so light that they cannot contribute appreciably to the mass density of the Universe.

• OSTI ID: 6101388
• Journal Information: Physical Review, D (Particles Fields); (USA), Journal Name: Physical Review, D (Particles Fields); (USA) Vol. 42:10; ISSN PRVDA; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

640106* -- Astrophysics & Cosmology-- Cosmology
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ASYMMETRY
BARYON NUMBER
BARYONS
COSMOLOGY
ELEMENTARY PARTICLES
FERMIONS
FIELD THEORIES
HADRONS
INVARIANCE PRINCIPLES
LEPTON NUMBER
MASS
MATHEMATICAL MODELS
NEUTRONS
NUCLEONS
PARTICLE MODELS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
STANDARD MODEL
SYMMETRY BREAKING
THERMODYNAMIC PROPERTIES
UNIFIED GAUGE MODELS
UNIFIED-FIELD THEORIES
UNIVERSE
WEINBERG-SALAM GAUGE MODEL