Modelling collisions From a Supernova

Massive stars end their lives in explosions called a core-collapse Supernova. These explosions produce large numbers of weakly interacting particles called neutrinos. A new paper in Physical Review C explains how MARLEY provides the first theoretical model which predicts all information for charged-current collisions of Supernova electron neutrinos with argon.

Scientists working on the Deep Underground Neutrino Experiment, hosted by Fermilab, are seeking to perform a detailed measurement of Supernova neutrinos. This effort could lead to discoveries in particle physics and astrophysics, including the first observation of the transition of a Supernova into a neutron star or black hole.To detect Supernova neutrinos, DUNE will mostly search for reactions in which a neutrino collides with an argon nucleus and transforms into an electron. Precise 3D images of charged-current reactions will be recorded by advanced particle detectors. The images will then be compared with the outcomes of simulations.

A new computer program called MARLEY, described in this manuscript, generates the first complete simulations of charged-current reactions between Supernova neutrinos and argon nuclei.The program provides researchers to study a variety of scientific questions. Physicists can use it to understand what measurements from DUNE might be able to tell us about the nature of neutrinos, stars and the wider universe.

Experimental physicists can use MARLEY to practice analyzing the fake data from a simulated supernova in preparation for the real thing. This constructs on pioneering reconstruction techniques first developed for the ArgoNeuT experiment and published in Physical Review D, the MicroBooNE collaboration carried out such simulations recently. All of these physics analysis tasks can be accomplished without requiring MARLEY users to be experts in nuclear physics. Several scientific papers have been published that include results calculated with MARLEY, and more are expected in the future.

One of the most useful pieces of information that DUNE scientists plan to measure is the energy of each Supernova neutrino that scatters within the detector. A full description of each neutrino collision includes the energy and direction of the electron, as well as similar details about the ejected nuclear particles.