In comparison with J/\psi, the excited charmonium state \psi^\prime is
loosely bounded and its yield is dominantly from the B-hadron decay. Based on
the transport approach, we study the double ratio of N(\psi^\prime)/N(J/\psi)
from A+A collisions to that from p+p collisions at LHC energy. We found that
the primordial production in the initial stage and the regeneration in the hot
medium are not significant for \psi^\prime production in heavy ion collisions
at LHC and the double ratio in semi-central and central collisions is
controlled by the B decay.Comment: 5 pages, 7 figure