Decoherence in supernova neutrino transformations suppressed by deleptonization

Journal Article · Sat Dec 15 04:00:00 EST 2007 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.76.125018· OSTI ID:21024083

Esteban-Pretel, Andreu; Pastor, Sergio; Tomas, Ricard ^[1]; Raffelt, Georg G ^[2]; Sigl, Guenter ^[3]

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1. AHEP Group, Institut de Fisica Corpuscular, CSIC/Universitat de Valencia, Edifici Instituts d'Investigacio, Apt. 22085, 46071 Valencia (Spain)
2. Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut), Foehringer Ring 6, 80805 Munich (Germany)
3. II. Institut fuer theoretische Physik, Universitaet Hamburg, Luruper Chaussee 149, D-22761 Hamburg (Germany) and APC (AstroParticules et Cosmologie), 10, rue Alice Domon et Leonie Duquet, 75205 Paris Cedex 13 (France)

In the dense-neutrino region at 50-400 km above the neutrino sphere in a supernova, neutrino-neutrino interactions cause large flavor transformations. We study when the multiangle nature of the neutrino trajectories leads to flavor decoherence between different angular modes. We consider a two-flavor mixing scenario between {nu}{sub e} and another flavor {nu}{sub x} and assume the usual hierarchy F{sub {nu}{sub e}}>F{sub {nu}{sub e}}>F{sub {nu}{sub x}}=F{sub {nu}{sub x}} for the number fluxes. We define {epsilon}=(F{sub {nu}{sub e}}-F{sub {nu}{sub e}})/(F{sub {nu}{sub e}}-F{sub {nu}{sub x}}) as a measure for the deleptonization flux which is the one crucial parameter. The transition between the quasi-single-angle behavior and multiangle decoherence is abrupt as a function of {epsilon}. For typical choices of other parameters, multiangle decoherence is suppressed for {epsilon} > or approx. 0.3, but a much smaller asymmetry suffices if the neutrino mass hierarchy is normal and the mixing angle small. The critical {epsilon} depends logarithmically on the neutrino luminosity. In a realistic supernova scenario, the deleptonization flux is probably enough to suppress multiangle decoherence.

• OSTI ID: 21024083
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 12 Vol. 76; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ASYMMETRY
ELECTRON NEUTRINOS
FLAVOR MODEL
NEUTRINO-NEUTRINO INTERACTIONS
QUANTUM DECOHERENCE
REST MASS
STANDARD MODEL
SUPERNOVAE
TRANSFORMATIONS
WEINBERG ANGLE