Gravitational waves from phase transitions of accreting neutron stars

We propose that when neutron stars in low-mass X-ray binaries accrete sufficient mass and become millisecond pulsars, the interiors of these stars may undergo phase transitions, exciting stellar radial oscillations. We show that the radial oscillations will be mainly damped by gravitational-wave radiation instead of internal viscosity. Such gravitational waves may be detected by the advanced Laser Interferometer Gravitational-wave Observatory.