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Introduction
In this section we provide information relating to neutrino interactions with
matter, starting with neutrino loss rates from thermal processes.
We also present tables of cross sections and particle evaporation
branching ratios for charged current and neutral current inelastic neutrino
scattering reactions involving intermediate mass target nuclei from 12C to 80Kr.
The tables are given for a select set of neutrino energies and are based on the
work of Wick Haxton as discussed in
Woosley, Hartmann, Hoffman, and Haxton
(1990). For a discussion of how these are implemented in reactions networks,
click here.
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Thermal Neutrino Loss Rates
Stellar neutrino energy loss rates from thermal processes (the sum of pair,
plasma, photo,
bremsstrahlung, and recombination) are calculated according to
Itoh et al. (1996). An excellent treatement
that includes useful plots and the necessary computer codes to
calculate all the loss rates (and their derivatives) can be found on
Frank Timmes Web
Site.
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Neutral and Charged Current Cross Sections
We tabulate neutral and charged current cross sections per nucleon (in units
of 10-42 sq. cm) averaged over a normalized Fermi-Dirac distribution for three
neutrino temperatures T_nu = 4, 6, and 8 Mev. Listed are the
neutral current inelastic scattering cross section (sigma_neut),
and the
charged current electron-neutrino (sigma_e-)
and anti-electron-neutrino (sigma_e+)
cross sections for target nucleus (Z,A).
In our latest calculations of neutrino nucleosynthesis
in massive stars
(Rauscher, Heger, Hoffman, & Woosley 2002) we
we simulated the supernova neutrino emission by a neutrino pulse with a mean energy of 4 MeV for the
electron neutrinos and 6 MeV for the nu and tau neutrinos with a total energy of 3x1053 erg
decaying exponetially on a time scale of 3 seconds.
Charged and Neutral Current Neutrino Cross Sections
[4 MeV],
[6 Mev],
[8 MeV]
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Neutral Current Branching Ratios
We provide neutral current branching ratios for two neutrino temperatures
T_nu_mu and T_nu_tau = 6 and 8 MeV.
Listed are the probabilities for neutron (Bn), proton (Bp),
alpha (Balpha), and gamma (Bgamma) particle emission following inelastic
neutrino scattering off of the target nucleus (Z,A).
Neutral Current Branching Ratios
[6 Mev],
[8 MeV]
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Charged Current Branching Ratios
Finally, we tabulate charged current branching ratios for Tnu_e = 4 and 6 MeV.
Listed are the probabilities for neutron (Bnbeta-), proton (Bpbeta-), and gamma
(Bgammabeta-) particle emission following electron-neutrino capture on target
nucleus (Z,A), and similar probabilities (Bnbeta+, Bpbeta+, and Bgammabeta-),
for particle emission following anti-electron-neutrino capture on target nucleus
(Z,A). The probabilities for alpha-emission (negligable) are not listed.
Charged Current Branching Ratios
[4 Mev],
[6 MeV]
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Special Cases for 4He and 12C
As a special case, the neutral current neutrino
scattering cross sections and branching ratios for scattering off of 4He and
8Be. [Table]. Also
provided are special neutral current
de-excitation branching ratios for 12C with decay proceeding through
the exit channels n, p, alpha, p+n, alpha+p, alpha+n, 3He, 3He+n, and 3H+p.
[Table]
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