  We consider composite bosons (cobosons) comprised of two elementary
particles, fermions or bosons, in an entangled state. First, we show that the
effective number of cobosons implies the level of correlation between the two
constituent particles. For the maximum level of correlation, the effective
number of cobosons is the same as the total number of cobosons, which can
exhibit the original Bose-Einstein condensation (BEC). In this context, we
study a model of BEC for indistinguishable cobosons with a controllable
parameter, i.e., entanglement between the two constituent particles. We find
that bi-fermions behave in a predictable way, i.e., the effective number of the
ground state coboson is an increasing function of entanglement between a pair
of constituent fermions. Interestingly, bi-bosons exhibit the opposite
behaviour - the effective number of the ground state coboson is a decreasing
function of entanglement between a pair of constituent bosons.
