Coherent and incoherent Upsilon production in ultraperipheral collisions at the Large Hadron Collider

Abstract

The exclusive photoproduction of Υ(nS) states were calculated in ultra-peripheral collisions for coherent and incoherent process in PbPb at √ sNN = 5.5 TeV. Different dipole models were compared in the theoretical framework of light-cone color dipole formalism. Moreover, it was calculated the differential cross section for the Upsilon states and their total cross section for two intervals of rapidity: |y| ≤ 4 4 and 2 ≤ y ≤ 4.5. A systematic study is done on the theoretical uncertainties associated to the production and predictions are presented for the first time for the incoherent cross section of the radially excited states.

Exclusive photoproduction of excited quarkonia in ultraperipheral collisions

“…A number of different approaches for a detailed treatment of the incoherent photo-nuclear production have been developed in the literature so far; see, e.g., Refs. [74][75][76][77][78][79][80][81][82][83][84].…”

Photon induced processes: from ultraperipheral to semicentral heavy ion collisions

“…This however is not a complete review of the available literature, nor can we, due to space limitations, provide extensive discussions of the merits and shortcomings of different approaches. For applications of the color dipole approach to UPCs, some of them extending to light vector mesons and excited states, we refer the reader to [40][41][42][43][44][45][46][47][48][49][50][51][52]. The momentum space formulation, k ⊥factorization, which is equivalent to the dipole approach was used in [53], where also qqg-states were included.…”

Photoproduction of Upsilon states in ultraperipheral collisions at the LHC

“…In Ref. [6], a detailed study of the incoherent cross section for the upsilon states has been done. This is quite important, as it was pointed out that incoherent diffraction probes the fluctuations in the interactions strengths of multiparton Fock states in the nuclear wavefunctions [10].…”

“…[6,7], where we investigate the exclusive production of Υ(1S ) and its radially excited states Υ(2S ) and Υ(3S ) in PbPb collisions for LHC energy. In Ref.…”