  The ground state cooling of a mechanical oscillator in an optomechanical
cavity containing an ensemble of identical two-level ground-state atoms is
studied in the highly unresolved-sideband regime. The system exhibits
electromagnetically-induced transparency-like quantum interference effect. The
mutual interaction with the cavity optical field gives rise to an indirect
coupling between the atomic and mechanical modes. In presence of this
interaction, the noise spectrum gets modified and leads to asymmetric cooling
and heating rates. Using the quantum master equation, time evolution of the
average phonon number is studied and it is observed that the average phonon
occupancy in the mechanical resonator exhibits ground-state cooling.
