Exploring Nuclear Forces with Pulsar Glitch Observations

Abstract We connect nuclear forces to one of the most notable irregular behaviors observed in pulsars, already detected in approximately 6% of known pulsars, with increasingly accurate data expected from upcoming high-precision timing instruments both on the ground and in space. Built on Shang & Li, we conduct a case study on the 2000 glitch of the Vela pulsar. For our purpose, we adopt the relativistic mean field (RMF) model as the theoretical many-body framework to describe nuclear systems. We refit three representative RMF parameter sets (DD-ME2, PKDD, and NL3), considering the uncertainties in nuclear matter saturation properties. Utilizing the resulting star structure, composition, and nucleon properties in the medium obtained in a consistent manner, we calculate the pinning energy of the superfluid vortex in the nuclear lattice in the inner crust. This leads to the evolution of an associated pinning force that acts on the vortex, which can be confronted with the observed glitch amplitude and short time relaxation in the 2000 Vela glitch event, following the snowplow model of the pulsar glitch. We discuss how the vortex configuration and pinning properties depend on the nuclear parameters and find an interesting and dominant role of the nuclear symmetry energy slope in pinning strength.