super bunching effect of bosons

Let say we consider a $$N$$ pair of elementry bosons (i.e $$N$$ composite bosons). At very low temperature these bosons will condense into the ground state. If we find the mean occupation number $$\langle n\rangle$$ for a ground state sometime we get $$\langle n\rangle$$ greater then total number of composite bosons N. This is because constituent bosons are showing their bosonic nature individually. I need more explanation about this kind of bunching.

• First of all the condensation depends on the dimensionality of the system. Second could you point to a reference which lays out the context? E.g. the formula you use to get $\langle n \rangle$? – SuperCiocia Jan 23 at 19:47