Continuity from neutron matter to two-flavor quark matter with ${}^1{S}_0$ and ${}^3{P}_2$ superfluidity

Abstract

This study is performed with the aim of gaining insights into the possible applicability of the quark-hadron continuity concept, not only in the idealized case of three-flavor symmetric quark matter, but also for the transition from neutron matter to two-flavor quark matter. A key issue is the continuity between neutron superfluidity and a corresponding superfluid quark phase produced by $d$-quark pairing. Symmetry arguments are developed and relevant dynamical mechanisms are analyzed. It is pointed out that the ${}^3{P}_2$ superfluidity in dense neutron matter has a direct analogue in the ${}^3{P}_2$ pairing of $d$-quarks in two-flavor quark matter. This observation supports the idea that the quark-hadron continuity hypothesis may be valid for such systems. Possible implications for neutron stars are briefly discussed.

Comments: 14 pages, 5 figures; minor updates to promote correctness in discussions