Neutrino emissions in all flavors up to the pre-bounce of massive stars and the possibility of their detections [HEAP]

http://arxiv.org/abs/1704.05480


This paper is a sequel to our previous one, which calculated the luminosities and spectra of $\bar{\nu}_e$’s from progenitors of core-collapse supernovae. Expecting that a capability to detect $\nu_e$’s will increase dramatically with the emergence of liquid-argon detectors such as DUNE, we broaden the scope in this study to include all flavors of neutrinos emitted not only from the pre-collapse phase but also from the collapsing phase, in which $\nu_e$’s are predominantly generated. We pick up essentially the same progenitors of the so-called electron capture supernova (ECSN) and the ordinary iron-core collapse supernova (FeCCSN). In this paper, we take into account not only thermal pair productions but also $\beta$ processes on nuclei in nuclear statistical equilibrium. We find that the number luminosities reach $\sim10^{57}\ \mathrm{s^{-1}}$ and $\sim10^{53}\ \mathrm{s^{-1}}$ at maximum for $\nu_e$ and $\bar{\nu}_e$, respectively. We also estimate the numbers of expected detection events at terrestrial neutrino detectors including DUNE, taking neutrino oscillations into account and assuming the distance to the progenitors to be 200 pc. It is demonstrated that $\bar{\nu}_e$’s from the ECSN-progenitor will be undetected at almost all neutrino detectors even if it is this close, whereas we will be able to observe $\sim$2500 $\nu_e$’s at DUNE for the inverted mass hierarchy. From the FeCCSN-progenitors, the number of $\bar{\nu}_e$ events will be largest for JUNO, 134-725 $\bar{\nu}_e$’s, depending on the mass hierarchy whereas the number of $\nu_e$ events at DUNE is almost the same as that for the ECSN-progenitor. These results imply that the detection of $\bar{\nu}_e$’s is useful to distinguish the type of progenitor, while $\nu_e$’s will provide us with detailed information on the collapse phase regardless of the type and mass of progenitor.

Read this paper on arXiv…

C. Kato, S. Yamada, H. Nagakura, et. al.
Thu, 20 Apr 17
10/49

Comments: 24 pages, 14 figures, 4 tables, submitted to ApJ