http://arxiv.org/abs/2212.01155
In this paper, we evaluate the energy loss rate of supernovae induced by the axion emission process $\pi^- + p \to n + a$ with the $\Delta(1232)$ resonance in the heavy baryon chiral perturbation theory for the first time. Given the axion-nucleon-$\Delta$ interactions, we include the previously ignored $\Delta$-mediated graphs to $\pi^- + p \to n + a$ process. In particular, the $\Delta^0$-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 $\Delta(1232)$ mass. With these new contributions, we find that for the typical supernova temperatures, compared to the earlier work, the supernova axion emission rate can be enhanced by a factor of $\sim$ 4 in the KSVZ model and up to a factor of $\sim$5 in the DFSZ model with small $\tan\beta$ values. Remarkably, we notice that the $\Delta(1232)$ resonance gives a destructive contribution to the supernova axion emissivity at high supernova temperatures, which is a nontrivial result in this study.
S. Ho, J. Kim, P. Ko, et. al.
Mon, 5 Dec 22
29/63
Comments: 16 pages, 4 figures. Comments are welcome