# Deeply bound dibaryon is incompatible with neutron stars and supernovae

McDermott, Samuel D. (Fermi National Accelerator Laboratory, Theoretical Astrophysics Group, Batavia, 60510 Illinois, USA) ; Reddy, Sanjay (Institute for Nuclear Theory, University of Washington, 98105 Seattle, Washington, USA) ; Sen, Srimoyee (Institute for Nuclear Theory, University of Washington, 98105 Seattle, Washington, USA)

12 February 2019

Abstract: We study the effect of a dibaryon $S$ in the mass range $1860<{m}_{S}<2054\text{}\text{}\mathrm{MeV}$, which is heavy enough not to disturb the stability of nuclei and light enough to possibly be cosmologically metastable. Such a deeply bound state can act as a baryon sink in regions of high baryon density and temperature. We find that the ambient conditions encountered inside a newly born neutron star are likely to sustain a sufficient population of hyperons to ensure that a population of $S$ dibaryons can equilibrate in less than a few seconds. This would be catastrophic for the stability of neutron stars and the observation of neutrino emission from the proto-neutron star of Supernova 1987A over $\sim O\left(10\right)\text{}\text{}s$. A deeply bound dibaryon is therefore incompatible with the observed supernova explosion, unless the cross section for $S$ production is severely suppressed.

Published in: Physical Review D 99 (2019)