Speaker
Description
In this talk, we evaluate the energy loss rate of supernovae induced by the axion emission process π− + p → n + a with the ∆(1232) resonance in the heavy baryon chiral perturbation theory for the first time. Given the axion-nucleon-∆ interactions, we include the previously ignored ∆-mediated graphs to the π− + p → n + a process. In particular, the ∆0-mediated diagram can give a resonance contribution to the supernova axion emission rate when the center-of-mass energy of the pion and proton approaches
the ∆(1232) mass. With these new contributions, we find that for the typical supernova temperatures, compared with the earlier work with the axion-nucleon (and axion-pion-nucleon contact) interactions, the supernova axion emissivity can be enhanced by a factor of ∼ 4 (2) in the Kim-Shifman-VainshteinZakharov model and up to a factor of ∼ 5 (2) in the Dine-Fischler-Srednicki-Zhitnitsky model with small tan β values. Remarkably, we notice that the ∆(1232) resonance gives a destructive contribution to thesupernova axion emission rate at high supernova temperatures, which is a nontrivial result in this study.
