B-11 and Constraints on Neutrino Oscillations and Spectra from Neutrino Nucleosynthesis

National Superconducting Cyclotron Laboratory and Joint Institute for Nuclear Astrophysics, 1 Cyclotron, Michigan State University, East Lansing, Michigan 48824-1321, USA.
Physical Review Letters (Impact Factor: 7.73). 04/2011; 106(15):152501. DOI: 10.1103/PhysRevLett.106.152501
Source: PubMed

ABSTRACT We study the sensitivity to variations in the triple-alpha and 12C(α,γ)16O reaction rates, of the yield of the neutrino-process isotopes 7Li, 11B, 19F, 138La, and 180Ta in core-collapse supernovae. Compared to solar abundances, less than 15% of 7Li, about 25%-80% of 19F, and about half of 138La is produced in these stars. Over a range of ±2σ for each helium-burning rate, 11B is overproduced and the yield varies by an amount larger than the variation caused by the effects of neutrino oscillations. The total 11B yield, however, may eventually provide constraints on supernova neutrino spectra.

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    ABSTRACT: Core-collapse supernovae eject huge amount of flux of energetic neutrinos which affect explosive nucleosynthesis of rare isotopes like 7Li, 11B, 92Nb, 138La and Ta and r-process elements. Several isotopes depend strongly on the neutrino flavor oscillation due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. We here discuss how to determine the neutrino temperatures and propose a method to determine still unknown neutrino oscillation parameters, mass hierarchy and θ13, simultaneously. Combining the recent experimental constraints on θ13 with isotopic ratios of the light elements discovered in presolar grains from the Murchison meteorite, we show that our method suggests at a marginal preference for an inverted neutrino mass hierarchy. We also discuss supernova relic neutrinos that may indicate the softness of the equation of state (EoS) of nuclear matter as well as adiabatic conditions of the neutrino oscillation.
    04/2014; 1594(1). DOI:10.1063/1.4874089
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    ABSTRACT: Neutrino interactions are a key component of the mechanism for supernova explosions. They also play an important role in the associated nucleosynthesis. Nevertheless, a number of issues remain to be resolved. In this review we summarize research by our group and others on some of these issues. Foremost is the role of neutrinos in the explosion itself. Much effort is now invested in understanding the transport of neutrinos from the core and the role of neutrino heated convection in the outer envelopes. In addition to the neutrino transport issues, we review some current topics in neutrino-induced nucleosynthesis (the ν- and νp-processes). We review some current issues regarding the synthesis of the ν-process isotopes 180Ta and 138La and summarize the application of the ν-process chronometers, 136, 138Ce, 138La, and 92Nb. We also consider the light ν-process isotopes 7Li and 11B and summarize how neutrino oscillations and nucleosynthesis might constrain the neutrino mass hierarchy. We will also review the current dilemma regarding the nucleosynthesis of heavy elements by rapid neutron capture in the neutrino energized wind above the nascent neutron star. We also review the crucial role of neutrino reactions and heating above the high-temperature accretion disc around the black hole of a failed supernova (collapsar model). This collapsar model for long-duration gamma ray bursts is a possible site for r-process nucleosynthesis. We present numerical r-process calculations in the context of a magnetohydrodynamics + neutrino pair heated collapsar simulation. Neutrino heating of the jet is crucial for achieving the required relativistic outflow and at the same time generating material with a high neutron excess. During the late time evolution of the jet an r-process-like abundance distribution is formed within neutrino heated regions of the relativistic outflowing jet. Indeed, sufficient mass is ejected within the flow to account for the observed r-process abundance distribution along with the large dispersion in r-process elements observed in metal-poor halo stars. Finally, we discuss the nuclear physics issues and possible role of relic supernova neutrinos in resolving the supernova rate problem.
    Journal of Physics G Nuclear and Particle Physics 02/2014; 41(4):044007. DOI:10.1088/0954-3899/41/4/044007 · 2.84 Impact Factor
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    ABSTRACT: We studied the explosive nucleosynthesis in core-collapse supernovae and found that several isotopes of rare elements like {sup 7}Li, {sup 11}B, {sup 138}La, {sup 180}Ta and others are predominantly produced by the neutrino interactions with several abundant nuclei. These isotopes are strongly affected by the neutrino flavor oscillation due to the MSW (Mikheyev-Smirnov-Wolfenstein) effect. We here first study how to know the suitable average neutrino temperatures in order to explain the observed solar system abundances of these isotopes, combined with Galactic chemical evolution of the light nuclei and the heavy r-process elements. We then study the neutrino oscillation effects on their abundances, and propose a new novel method to determine the neutrino oscillation parameters, {theta}{sub 13} and mass hierarchy, simultaneously. There is recent evidence that some SiC X grains from the Murchison meteorite may contain supernova-produced neutrino-process {sup 11}B and {sup 7}Li encapsulated in the grains. Combining the recent experimental constraints on {theta}{sub 13}, we show that although the uncertainties are still large, our method hints at a marginal preference for an inverted neutrino mass hierarchy for the first time.
    11/2012; 1498(1). DOI:10.1063/1.4768500


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