Hadron Multiplicities in Pb+Pb Collisions at the Large Hadron Collider and Pomeron Loop Effects

We study the pseudo-rapidity distribution of hadron multiplicities of high energy Pb+Pb collisions by using color glass condensate dynamics at LHC/ALICE in the fixed coupling case. It is found that after including the pomeron loop effects the charged hadron multiplicities at central rapidity are about 1500 for central Pb+Pb collisions, which are significantly smaller than the saturation based calculations,~1700÷2500 and compatible with that based on a study of multiplicities in the fragmentation region.