Bottomonium suppression at $\sqrt{s_{NN}}=2.76$ TeV using model based on color screening and gluonic dissociation with collisional damping

Abstract

We present a model to explain the bottomonium suppression in Pb+Pb collisions at mid rapidity obtained from Large Hadron Collider (LHC) energy, $\sqrt{s_{NN}}=2.76$ TeV. The model consists of two decoupled mechanisms namely, color screening during bottomonium production followed by gluon induced dissociation along with collisional damping. The quasi-particle model (QPM) is used as equation of state (EOS) for the Quark-Gluon Plasma (QGP) medium. The feed-down from higher $\Upsilon$ states, such as $\Upsilon(1P)$, $\Upsilon(2S)$ and $\Upsilon(2P)$, dilated formation times for bottomonium states and viscous effect of QGP medium are other ingredients included in the current formulation. We further assume that the QGP is expanding according to (1+1)-dimensional Bjorken's boost invariant scaling law. The net suppression (in terms of $p_T$ integrated survival probability) for bottomonium states at mid rapidity is obtained as a function of centrality and the result is then compared both quantitatively and qualitatively with the recent LHC experimental data in the mid rapidity region recently published by CMS collaboration. We find that the current model, based on the Debye color screening plus gluonic dissociation along with collisional damping, better describes the centrality dependence of bottomonium suppression at LHC energy as compared to color screening model alone. \vskip 0.5cm {\nd \it Keywords} : Color screening, Gluonic dissociation, Collisional damping, Survival probability {\nd \it PACS numbers} : 12.38.Mh, 12.38.Gc, 25.75.Nq, 24.10.Pa