$\psi (2S)$ enhancement in p-Pb collision as an indication of QGP formation at the LHC

Abstract

Proton-nucleus collisions serve as an important baseline for the understanding and interpretation of the nucleus-nucleus collisions. These collisions have been employed to characterize the cold nuclear matter effects at SPS and RHIC energies for the past several years, as it was thought that Quark-Gluon Plasma (QGP) is not formed in such collisions. However, at the Large Hadron Collider (LHC), there seems a possibility that QGP is formed during proton-lead (p$-$Pb) collisions. In this work, we have derived an expression for gluon induced excitation of $J/\psi$ to $\psi (2S)$, using pNRQCD, and show that the relative enhancement of $\psi (2S)$ vis a vis $J/\psi$, especially at high $p_T$, gives further indication that the QGP is indeed formed in p$-$Pb collisions at the most central collisions at LHC energy. $J/\psi$ and $\psi (2S)$ suppression effects seen at ALICE are also qualitatively explained.

17 pages, 11 figures. Accepted for publication in Journal of Physics G

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• Static quark-antiquark pairs at finite temperature
• High transverse momentum quarkonium production and dissociation in heavy ion collisions
• Glauber modeling of high-energy nuclear collisions at sub-nucleon level
• Cold and Hot Nuclear Matter Effects on Charmonium Production in p+Pb Collisions at LHC Energy
• Colour screening scenario for quarkonia suppression in a quasiparticle model compared with data obtained from experiments at the CERN SPS, BNL RHIC, and CERN LHC
• $J/\psi$ suppression in Au+Au collisions at RHIC : colour screening scenario in the bag model at variable participant numbers
• Temperature dependent formation-time approach for ${\rm Y}$ suppression at energies available at the CERN Large Hadraon Collider

Cited by in corpus (5)

• Centrality and transverse momentum dependent suppression of ${\rm Y}(1S)$ and ${\rm Y}(2S)$ in p$-$Pb and Pb$-$Pb collisions at the CERN Large Hadron Collider
• Impact of Medium Anisotropy on Quarkonium Dissociation and Regeneration
• Exploring QGP-like phenomena with Charmonia in $p+p$ collisions at $\sqrt{s}=13$ TeV
• Dissociation-driven quarkonium spin alignment in Pb--Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV
• Spin alignment of Quarkonia: A Possible Probe of Deconfined QCD matter in Pb+Pb Collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV