Speaker
Description
We study the bulk viscosity of moderately hot and dense, neutrino-transparent colour superconducting quark matter arising from weak-interaction-driven direct URCA processes. The quark matter is modeled using the Nambu-Jona-Lasinio model extended to include both vector interactions and the 't Hooft determinant term. The superconducting phase is described by using the two-flavour red-green paired colour-superconducting (2SC) phase, while allowing for the presence of unpaired strange quarks and blue colour light flavours. We compute the relaxation rates associated with d and s-quark decay and electron capture processes on u quark for blue colour, the associated bulk viscosity, as well as the damping timescales in the frequency range 1-10 kHz, relevant to binary neutron star mergers. Our results show that the damping of density oscillations in 2SC phase can be a leading mechanism of dissipation in merging hybrid stars containing colour-superconducting cores and is quantitatively similar to that predicted for nucleonic matter.
