The angular distribution of the reaction $\bar{\nu}_e + p \to e^+ + n$

摘要: The reaction $\bar{\nu}_e + p \to e^+ n$ is very important for low-energy ($E_\nu \lesssim 60$ MeV) antineutrino experiments. In this paper we calculate the positron angular distribution, which at low energies slightly backward. We show that weak magnetism and recoil corrections have a large effect on making it isotropic about 15 MeV forward higher energies. also behavior of cross section distribution can be well-understood analytically $E_\nu by calculating to ${\cal O}(1/M)$, where $M$ nucleon mass. correct useful separating events from other reactions detector backgrounds, as well possible localization source (e.g., supernova) direction. comment how similar appear lepton distributions in deuteron breakup d n $\nu_e e^- p$. Finally, n$, outgoing neutrons strongly forward-peaked, leading measurable separation neutron detection points, potentially rejecting backgrounds or locating