XXVIII International Workshop on Deep-Inelastic Scattering and Related Subjects

Latest ALICE results on J/ψ photoproduction in ultra-peripheral collisions at the LHC

15 Apr 2021, 08:18

18m

Virtual (Stony Brook, NY)

Contributed Talk Small-x, Diffraction and Vector Mesons Small-x, Diffraction and Vector Mesons

Speaker

Tomas Herman

Description

Ultra-peripheral collisions (UPCs) at the LHC, studied using the ALICE detector, allow us to investigate, using photon-induced interactions, processes sensitive to the low x behaviour of the gluon distribution of the colliding particles and provide important constraints on the initial stages of the collision.

The first measurement of the t-dependence of the coherent $\mathrm{J}/\psi$ photonuclear cross section is presented. The cross section is obtained at midrapidity from Pb–Pb UPCs at $\sqrt{s_{\mathrm{N}\mathrm{N}}}$=5.02 TeV. This observable provides a new tool to investigate the transverse gluonic structure at low Bjorken-x.

Moreover, a new rapidity-differential measurement of the coherent photoproduction of $\mathrm{J}/\psi$ at midrapidity in Pb–Pb UPCs at $\sqrt{s_{\mathrm{N}\mathrm{N}}}$=5.02 TeV is reported. This result complements the ALICE measurement of the coherent $\mathrm{J}/\psi$ cross section at forward rapidity allowing us to provide stringent constraints on nuclear gluon shadowing and saturation models at small Bjorken-x.

In addition, prospects for heavy vector meson photoproduction measurements in LHC Run 3 and 4 will be presented.

Presentation materials

DIS-2021_vFinal.pdf

Youtube Link