http://arxiv.org/abs/1608.03348
“Subthreshold pions” and so-called “hard photons” are two important channels for producing less than 1 GeV $\gamma$-rays and $e^\pm$ pairs from nuclear collisions with energy per nucleon below the $\pi$-meson production threshold. I use publicly available experimental data to parametrize these two channels’ $\gamma$-ray and $e^\pm$ production cross sections and extend the pion contribution to these particles spectra at higher energies using their corresponding spectra from $pp$ interactions. These parametrizations are valid for collision energy $T_p\leq 100$ A GeV and agree reasonably well with the available experimental data. The new parametrizations allow, for the first time, accurate studies of astrophysical $\gamma$-rays below 1 GeV.
E. Kafexhiu
Fri, 12 Aug 16
32/38
Comments: 18 pages, 15 figures submitted to PRC