Large lepton mixing and supernova 1987A

Abstract

We reconsider the impact of ${\bar{\nu }}_e\leftrightarrow {\bar{\nu }}_{\mu ,\tau }$ neutrino oscillations on the observed ${\bar{\nu }}_e$ signal of supernova SN 1987A. Performing a maximum-likelihood analysis using as fit parameters the released binding energy $\Eb$ and the average neutrino energy $\Ee$, we find as previous analyses that ${\bar{\nu }}_e\leftrightarrow {\bar{\nu }}_{\mu ,\tau }$ oscillations with large mixing angles have lower best-fit values for $\Ee$ than small-mixing angle (SMA) oscillations. Moreover, the inferred value of $\Ee$ is already in the SMA case lower than those found in simulations. This apparent conflict has been interpreted as evidence against the large mixing oscillation solutions to the solar neutrino problem. In order to quantify the degree to which the experimental data favour the SMA over the large mixing solutions we use their likelihood ratios as well as a Kolmogorov-Smirnov test. We find within the range of SN parameters predicted by simulations regions in which the LMA-MSW solution is either only marginally disfavoured or favoured compared to the SMA-MSW solution. We conclude therefore that the LMA-MSW solution is not in conflict with the current understanding of SN physics. In contrast, the vacuum oscillation and the LOW solutions to the solar neutrino problem can be excluded at the $4\sigma$ level for most of the SN parameter ranges found in simulations. Only a marginal region with low values of $\Ee$, $<E_{{\bar{\nu }}_{\mu ,\tau }}>$ and $\Eb$ is left over, in which these oscillation solutions can be reconciled with the neutrino signal of SN 1987A.

23 pages, 20 figures, v2: brief comments added

References in corpus (1)

• Four--Neutrino Oscillations at SNO

Cited by in corpus (20)

• Neutrino oscillations and signals in beta and 0nu2beta experiments
• Detection of Neutrinos from Supernovae in Nearby Galaxies
• Probing oscillations into sterile neutrinos with cosmology, astrophysics and experiments
• Probing the neutrino mass hierarchy and the 13-mixing with supernovae
• Absolute Neutrino Mass Determination
• The diffuse supernova neutrino flux, supernova rate and SN1987A
• Supernova neutrino oscillations: A simple analytical approach
• Supernova neutrinos: difference of nu_mu - nu_tau fluxes and conversion effects
• Neutrinos from SN1987A: flavor conversion and interpretation of results
• Neutrino Spectrum from SN 1987A and from Cosmic Supernovae
• Axion Astrophysics
• Probing supernova physics with neutrino oscillations
• New analysis of the SN 1987A neutrinos with a flexible spectral shape
• Supernova 1987A did not test the neutrino mass hierarchy
• SN1987A and the Status of Oscillation Solutions to the Solar Neutrino Problem (including an appendix discussing the NC and day/night data from SNO)
• Signatures of Supernova Neutrino Oscillations into Extra Dimensions
• Testing the principle of equivalence by supernova neutrinos
• Supernova neutrinos: Earth matter effects and neutrino mass spectrum
• Theoretical Aspects of Neutrino Oscillation
• Neutrinos from Supernovae