Weak magnetism for antineutrinos in supernovae

By C. Horowitz. 2001

175 citations recorded by the source corpus.

Weak magnetism increases antineutrino mean free paths in core collapse supernovae. The parity violating interference between axial vector and vector currents makes antineutrino-nucleon cross sections smaller than those for neutrinos. We calculate simple, exact correction factors to include recoil and weak magnetism in supernova simulations. Weak magnetism may significantly increase the neutrino energy flux. We calculate, in a diffusion approximation, an increase of order 15% in the total energy flux for temperatures near 10 MeV. This should raise the neutrino luminosity. Weak magnetism also changes the emitted spectrum of ${\overline{\ensuremath{\nu}}}_{x}$ (with $x=\ensuremath{\mu}$ or $\ensuremath{\tau})$ and ${\overline{\ensuremath{\nu}}}_{e}.$ We estimate that ${\overline{\ensuremath{\nu}}}_{x}$ will be emitted about 7% hotter than ${\ensuremath{\nu}}_{x}$ because ${\overline{\ensuremath{\nu}}}_{x}$ have longer mean free paths. Likewise weak magnetism may increase the ${\overline{\ensuremath{\nu}}}_{e}$ temperature by of order 10%. This increase in temperature coupled with the increase in neutrino luminosity should increase the heating in the low density region outside of the neutrino sphere. This, in turn, could be important for the success of an explosion. It is important to check our results with a full simulation that includes Boltzmann neutrino transport and weak magnetism corrections.

Subfields: Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/f6329d7b750380aaddb54a4bfb34867eb28007b9

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Citations in the corpus

Origin of the heaviest elements: The rapid neutron-capture process (2019, background): “neutrino and antineutrino absorption (Horowitz, 2002) with mu being the nucleon mass.”
NEUTRINO-DRIVEN EXPLOSION OF A 20 SOLAR-MASS STAR IN THREE DIMENSIONS ENABLED BY STRANGE-QUARK CONTRIBUTIONS TO NEUTRINO–NUCLEON SCATTERING (2015, background): “(2) with gsa = −0.2, Horowitz (2002) estimates 15, 21, 23% reduction of the neutral-current opacity for a neutron-proton mixture with electron fractions Ye = 0.2, 0.1, 0.05, which are typical values for the layer between neutrinosphere (at density ρ ∼ 1011 g cm−3) and ρ ∼ 1013 g cm−3 for hundreds…”
Explosion mechanism, neutrino burst and gravitational wave in core-collapse supernovae (2005, background): “Relatively small corrections to the standard neutrino interaction processes [67] such as the detailed reaction kinematics of nucleon thermal motions, recoil, and weak magnetism contributions [162] as well as nucleon bremsstrahlung (NN ′ NN ′ νν̄) [138], pair-annihilation/creations among different ne”
Exploring Fundamentally Three-dimensional Phenomena in High-fidelity Simulations of Core-collapse Supernovae (2018, methodology): “For the underlying neutrino interactions, we use isotropic scattering on nucleons, alpha particles, and heavy nuclei following Bruenn (1985); Burrows et al. (2006) with corrections for weak magnetism and recoil from Horowitz (2002).”
Precision big bang nucleosynthesis with improved Helium-4 predictions (2018, unknown): “…i/2(γµγν − γνγµ). gA is the axial current constant for nucleons (also sometimes written CA/CV or λ in the literature), and fwm is the weak magnetism constant whose numerical value is given by (Horowitz, 2002; Horowitz and Li, 2000; Ivanov et al., 2013) fwm = µp − µn 2 ' 1.793− (−1.913) 2 ' 1.853 .”
A successful 3D core-collapse supernova explosion model (2018, methodology): “The weak magnetism and recoil corrections for both absorption and scattering are incorporated as multiplicative factors, using the linear fits in neutrino energy of Horowitz (2002).”
AN OPEN-SOURCE NEUTRINO RADIATION HYDRODYNAMICS CODE FOR CORE-COLLAPSE SUPERNOVAE (2014, background): “Weak-magnetism corrections from Horowitz (2002) are applied.”
Probing the neutrino mass hierarchy and the 13-mixing with supernovae (2003, background): “5 MeV (3) is found to be valid with ∼ 20% accuracy over a large variety of physical situations [28].”
Protoneutron star evolution and the neutrino-driven wind in general relativistic neutrino radiation hydrodynamics simulations (2009, background): “…via the annihilation of trapped electron-neutrino pairs, νe + ν̄e νµ/τ + ν̄ν/τ, as well as contributions from nucleon-recoil and weak magnetism as studied in Horowitz (2002) are investigated in Fischer et al. (2009) and are not taken into account in the present study of the neutrino driven wind.”
Shock Breakout in Core-Collapse Supernovae and Its Neutrino Signature (2002, background): “The Weak Magnetism/Recoil Correction Our baseline 11 M⊙ model includes the weak magnetism/recoil correction to the charged-current opacities for νe and ν̄e and to the neutral-current scattering opacities off of nucleons for all neutrino species (Vogel 1984; Horowitz 1997,2002).”
Monte Carlo Study of Supernova Neutrino Spectra Formation (2002, methodology): “Nucleon correlations, ef- fective mass, and recoil were taken into account, following Burrows & Sawyer (1998, 1999), as well as weak magnetism effects (Horowitz 2002) and quenching of gA at high densities (Carter & Prakash 2002).”
A NEW MULTI-DIMENSIONAL GENERAL RELATIVISTIC NEUTRINO HYDRODYNAMICS CODE FOR CORE-COLLAPSE SUPERNOVAE. II. RELATIVISTIC EXPLOSION MODELS OF CORE-COLLAPSE SUPERNOVAE (2012, background): “…emphasized that the additional energy transfer to the medium in the nucleon scattering reactions is crucial for this effect, which cannot be accounted for by the mere change of the scattering and absorption opacity due to the reduction of the final lepton phase space (Schinder 1990; Horowitz 2002).”
Two-dimensional hydrodynamic core-collapse supernova simulations with spectral neutrino transport - I. Numerical method and results for a 15 solar mass star (2005, methodology): “As discussed in detail by Horowitz (2002) the effects of weak magnetism and nucleon recoil counterbalance each other for νe while in the case of ν̄e both effects add up leading to an appreciable net reduction of the standard opacities (computed according to Bruenn 1985).”
Neutrino opacities in nuclear matter (2004, background): “Perhaps, more importantly, these corrections appear with opposite sign for neutrinos and anti-neutrinos (Vogel 1984; Horowitz 2002), resulting in 10− 20% differences in the relative cross sections.”
Explosions of O-Ne-Mg cores, the Crab supernova, and subluminous type II-P supernovae (2005, methodology): “The reason for this difference compared to the older models is a refined description of neutrino spectra formation and in particular of charged-current neutrino-nucleon interactions, including the weak magnetism corrections that were pointed out to be relevant by Horowitz (2002).”