  We investigate the effects of the nonminimal coupling between the scalar
field dark energy (quintessence) and the dark matter on the two- point
correlation function. It is well known that this coupling shifts the turnover
scale as well as suppresses the amplitude of the matter power spectrum.
However, these effects are too small to be observed when we limit the coupling
strength to be consistent with observations. Since the coupling of quintessence
to baryons is strongly constrained, species dependent coupling may arise. This
results in a baryon bias that is dif- ferent from unity. Thus, we look over the
correlation function in this coupled model. We find that even the non-coupled
quintessence model gives the better fit to the correlation function compared to
the cosmo- logical constant model. We are also able to observe the enhancement
of the baryon acoustic oscillation (BAO) peak due to the increasing bias factor
of baryon from this species dependent coupling. In order to avoid the damping
effect of the BAO signature in the matter power spectrum due to nonlinear
clustering, we consider the coupling effect on the BAO bump in the linear
regime. This provides an alternative method to constrain the coupling of dark
energy to dark matter.
