Searching for the signature of a tetraneutron resonance

Abstract

Many environments in the universe give rise to conditions extreme enough to allow exotic forms of nuclear matter. Understanding how this matter interacts allows us to better understand the nuclear forces and astronomical phenomena such as neutron stars. A tetraneutron is an exotic nuclear form which is composed of four neutrons. Its existence is debated, with an open question whether they can be held together briefly in a short-lived resonant state. The existence of the tetraneutron state would be observable in reactions with four neutrons as their end product. At the IRIS facility at TRIUMF, an experiment involving the reaction ⁸He(d, ⁶Li)4n was carried out by reacting a beam of ⁸He with a deuterium target and measuring the kinematics of the resulting ⁶Li. The existence of the tetraneutron state could be determined from the missing mass spectrum. In order to be able to interpret the results of the experiment, the effect of the non-resonant four neutron final state must be determined. This is done by simulating the non-resonant reaction with five-body final state through the experimental setup. This thesis covers my work in building this simulation using the properties of the reaction and the experimental setup.