Speaker
Description
In just under a ten-second period, a supernova explosion ejects debris and photons, while up to 99% of its entire explosive energy is carried away by neutrinos, the smallest known weakly-interacting fundamental particles. The explosion emits all neutrino flavours at tens-of-MeV energies, but the electron neutrino charged-current interaction (CCI) is the only way to infer the neutrino type and allows for direct probing of the supernova exploding mechanism and the intrinsic properties of neutrinos. The cross section of this interaction is small, but its faint visible signal in liquid argon (LAr) can be taken advantage of in experiments that utilise LAr as their detector medium. Theoretical predictions of CCI vary greatly depending on the model and there is no experimental data at present, so I will be presenting how the Short Baseline Near Detector (SBND), based at the Fermilab National Laboratory near Chicago in the U.S., is aiming to be the first to perform this measurement. After just one year of operation, this experiment currently holds the record of the world’s largest dataset of neutrino-argon interactions, achieved by bombarding SBND’s active volume with neutrinos from the Booster Neutrino Beam (BNB). A subset of these neutrinos are produced by muons Decaying At Rest (DAR) within the beam pipe. This enormous flux of electron neutrinos, with tens-of-MeV energies, mimic those from a supernova explosion. To perform this measurement, beam flux and systematic uncertainty simulation, system trigger and reconstruction algorithms need to be re-examined and adapted to this lower energy range. I will summarise how SBND is addressing these challenges towards obtaining the first measurement of the charged-current electron neutrino cross section on argon at energies below 50 MeV, establishing the first experimental constraints of supernova neutrino detection in LAr.