Thermal Neutrino Loss Rates


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The tool sneut5.tbz implements the analytic fitting formulas of Itoh et al. 1996 for thermal neutrino losses. In addition, the tool also returns the neutrino loss rate and its derivatives with respect to its input values: temperature, density, and the composition variables abar and zbar.

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As shown in the first figure above, the thermal neutrino losses has several components:

⚬ Pair production: $e^+ + e^- \rightarrow \nu_e + {\bar \nu}_e$ dominates in massive stars, where $kT \ge 0.1 \ m_ec^2$ especially for $T_9 > 0.5$.

⚬ Photoneutrino: $e^{\pm} + \gamma \rightarrow e^{\pm} + \nu + \bar{ \nu}_e$

⚬ Plasmon neutrino: $\gamma_{{\rm plasmon}} \rightarrow \nu_e + \bar{ \nu}_e$

⚬ Bremsstrahlung: $e^- + A^Z \rightarrow e^- + A^Z + \nu_e + \bar{\nu}_e$

⚬ Recombination: $e^-_{\rm continuum} \rightarrow e^-_{\rm bound} + \nu_e + \bar{ \nu}_e$

Here is how the Itoh et al expressions look in the ρ-T plane for pure carbon:

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Please cite the relevant references if you publish a piece of work that use these codes, pieces of these codes, or modified versions of them. Offer co-authorship as appropriate.