  We consider hardcore bosons in two coupled chain of one dimensional lattices
at half filling with repulsive intra-chain interaction and inter-chain
attraction. This can be mapped on to a coupled chain of spin-1/2 XXZ model with
inter chain ferromagnetic coupling. We investigate various phases of hardcore
bosons (and related spin model) at zero temperature by density matrix
renormalization group method. Apart from the usual superfluid and density wave
phases, pairing of inter chain bosons leads to the formation of novel phases
like pair-superfluid and density wave of strongly bound pairs. We discuss the
possible experimental realization of such correlated phases in the context of
cold dipolar gas.
