Quark Matter 2015 - XXV International Conference on Ultrarelativistic Nucleus-Nucleus Collisions

Nuclear modification of J/ψ in Pb-Pb collisions at LHC energies

29 Sept 2015, 16:30

2h

Exhibition space 3 & 4

Board: 0620

Poster Quarkonia Poster Session

Speaker

Biswarup Paul (Saha Institute of Nuclear Physics (IN))

Description

The inclusive J/$\psi$ differential production cross-sections and nuclear modification factor as a function of $p_{\mathrm{T}}$ in Pb-Pb collisions at $\sqrt{s_{\mathrm{N}\mathrm{N}}}$ = 2.76 TeV have been calculated at forward rapidity (2.5 $<$ $y$ $<$ 4) and compared with the results reported by the ALICE Collaborations [arXiv:1506.08804v1]. The calculations have been carried out by estimating the pp cross-sections at $\sqrt{s}$ = 2.76 TeV within the framework of NRQCD [J. Phys. G: Nucl. Part. Phys. 42 065101 (2015)]. The cross-sections have been scaled by the Glauber model for Pb-Pb collisions and convoluted with the survival probability fraction due to color screening [Phys. Rev. D 37, 1851 (1988)]. The feed-down contributions from $\psi$(2S), ${\chi }_c$ and $B$ mesons to J/$\psi$ have been included to compare the inclusive results from ALICE. The comparison with experimental values shows a good agreement beyond $p_{\mathrm{T}}$ = 4 GeV for the three centrality bins namely, 0%$-$20%, 20%$-$40% and 40%$-$90%. These results indicate that the cold nuclear matter and recombination effects on J/$\psi$ production at forward rapidities in Pb-Pb collisions at $\sqrt{s_{\mathrm{N}\mathrm{N}}}$ = 2.76 TeV is negligible for $p_{\mathrm{T}}$ $>$ 4 GeV. Thus, in the high $p_{\mathrm{T}}$ domain ($p_{\mathrm{T}}$ $>$ 4 GeV), the observed suppression in the J/$\psi$ yield by ALICE Collaboration can solely be accounted by color screening. Results will also be shown for Pb-Pb collisions at higher energies.