If a light gluino exists , the lightest gluino-containing baryon , the { S } ^ { 0 } , is a possible candidate for self-interacting dark matter .
In this scenario , the simplest explanation for the observed ratio \Omega _ { dm } / \Omega _ { b } \approx 6 - 10 is that m _ { S ^ { 0 } } \sim 900 \mbox { MeV } \mbox { c } ^ { -2 } ; this is not at present excluded by particle physics .
Such an { S } ^ { 0 } could be present in neutron stars , with hyperon formation serving as an intermediate stage .
We calculate equilibrium compositions and equation of state for high density matter with the { S } ^ { 0 } , and find that for a wide range of parameters the properties of neutron stars with the { S } ^ { 0 } are consistent with observations .
In particular , the maximum mass of a nonrotating star is 1.7 - 1.8 M _ { \odot } , and the presence of the { S } ^ { 0 } is helpful in reconciling observed cooling rates with hyperon formation .