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Generation of Local CA1 γ Oscillations by Tetanic Stimulation
Published on: August 14, 2015
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Leptogenesis via Axion Oscillations after Inflation
Alexander Kusenko1,2, Kai Schmitz2, Tsutomu T Yanagida2
1Department of Physics and Astronomy, University of California, Los Angeles, California 90095-1547, USA.
Physical Review Letters
|July 17, 2015
Summary
A novel mechanism for baryogenesis via leptogenesis is proposed, utilizing axionlike fields and lepton number violation from heavy neutrinos. This method offers a minimal alternative to thermal leptogenesis, independent of heavy neutrino properties.
Area of Science:
- Particle Physics
- Cosmology
- Astroparticle Physics
Background:
- Baryogenesis explains the matter-antimatter asymmetry in the universe.
- Leptogenesis is a leading baryogenesis scenario involving lepton number violation.
- Axionlike scalar fields are hypothetical particles with potential cosmological implications.
Purpose of the Study:
- To explore a novel mechanism for baryogenesis via leptogenesis.
- To investigate the role of axionlike fields and lepton number violation in generating the baryon asymmetry.
- To present a minimal alternative to standard thermal leptogenesis.
Main Methods:
- Classical motion of an axionlike scalar field coupled to electroweak gauge bosons.
- Induction of an effective chemical potential for fermion number during reheating.
- Incorporation of rapid lepton number (L)-violating processes, specifically heavy Majorana neutrino exchange.
Main Results:
- The axionlike field's motion induces a fermion number chemical potential.
- Lepton number violation via heavy Majorana neutrinos is sufficient for baryogenesis.
- The proposed mechanism is insensitive to heavy neutrino masses and CP-violating phases.
Conclusions:
- A novel and minimal baryogenesis mechanism via leptogenesis is demonstrated.
- This mechanism offers an alternative to thermal leptogenesis, requiring a reheating temperature of at least 10^12 GeV.
- The model is consistent with heavy neutrino masses near the grand unification scale.
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