We present an exact analytical solution of the two-photon scattering in a
cavity optomechanical system. This is achieved by solving the quantum dynamics
of the total system, including the optomechanical cavity and the cavity-field
environment, with the Laplace transform method. The long-time solution reveals
detailed physical processes involved as well as the corresponding resonant
photon frequencies. We characterize the photon correlation induced in the
scattering process by calculating the two-photon joint spectrum of the
long-time state. Clear evidence for photon frequency anti-correlation can be
observed in the joint spectrum. In addition, we calculate the equal-time
second-order correlation function of the cavity photons. The results show that
the radiation pressure coupling can induce photon blockade effect, which is
strongly modulated by the phonon sideband resonance. In particular, we obtain
an explicit expression of optomechanical coupling strength determining these
sideband modulation peaks based on the two-photon resonance condition.Comment: 10 pages, 6 figure