Neutrino oscillations and the supernova 1987A signal
- Max-Planck-Institut fuer Physik, Foehringer Ring 6, 80805 Muenchen (Germany)
We study neutrino oscillations` effect on the interpretation of the supernova (SN) 1987A neutrino signal by means of a maximum-likelihood analysis. We focus on oscillations between {bar {nu}}{sub {ital e}} and {bar {nu}}{sub {mu}} or {bar {nu}}{sub {tau}} and those mixing parameters that would solve the solar neutrino problem. For the small-angle MSW solution ({Delta}{ital m}{sup 2}{approx_equal}10{sup -5} eV{sup 2}, sin{sup 2}2{Theta}{sub 0}{approx_equal}0.007), there are no significant oscillation effects on the Kelvin-Helmholtz cooling signal; we confirm previous values for the neutron-star binding energy and average spectral {bar {nu}}{sub {ital e}} temperature. There is marginal overlap between the upper end of the 95.4% C.L. inferred range of {l_angle}{ital E}{sub {bar {nu}}{sub {ital e}}}{r_angle} and the lower end of the range of theoretical predictions. Any admixture of the stiffer {bar {nu}}{sub {mu}} spectrum by oscillations aggravates the conflict between inferred experimental and predicted theoretical spectral properties. For mixing parameters near the large-angle MSW solution ({Delta}{ital m}{sup 2}{approx_equal}10{sup -5} eV{sup 2}, sin{sup 2}2{Theta}{sub 0}{approx_equal}0.7) the oscillations in the SN are adiabatic, but one needs to include the regeneration effect in the Earth which causes the Kamiokande and IMB detectors to observe different {bar {nu}}{sub {ital e}} spectra. For the solar vacuum solution ({Delta}{ital m}{sup 2}{approx_equal}10{sup -10} eV{sup 2}, sin{sup 2}2{Theta}{sub 0}{approx_equal}1) the oscillations in the SN are nonadiabatic; vacuum oscillations take place between the SN and the detector. If one of the two large-angle solutions were borne out by the upcoming round of solar neutrino experiments, one would conclude that the SN 1987A {bar {nu}}{sub {mu}} and/or {bar {nu}}{sub {ital e}} spectra had been much softer than predicted by current treatments of neutrino transport. {copyright} {ital 1996 The American Physical Society.}
- OSTI ID:
- 288987
- Journal Information:
- Physical Review, D, Vol. 54, Issue 1; Other Information: PBD: Jul 1996
- Country of Publication:
- United States
- Language:
- English
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