Prospects for quarkonium studies at the high-luminosity LHC

Abstract

We review the prospects for quarkonium-production studies in proton and nuclear collisions accessible during the upcoming phases of the CERN Large Hadron Collider operation after 2021, including the ultimate high-luminosity phase, with increased luminosities compared to LHC Runs 1 and 2. We address the current experimental and theoretical open issues in the field and the perspectives for future studies in quarkoniumrelated physics through the exploitation of the huge data samples to be collected in proton-proton, with integrated luminosities reaching up to L = 3 ab −1 , in proton-nucleus and in nucleus-nucleus collisions, both in the collider and fixed-target modes. Such investigations include, among others, those of: (i) the quarkonia produced in association with other hard particles; (ii) the χ Q and η Q down to small transverse momenta; (iii) the constraints brought in by quarkonia on gluon PDFs, nuclear PDFs, TMDs, GPDs and GTMDs, as well as on the low-x parton dynamics; (iv) the gluon Sivers effect in polarised-nucleon collisions; (v) the properties of the quark-gluon plasma produced in ultra-relativistic heavy-ion collisions and of collective partonic effects in general; and (vi) double and triple parton scatterings.

$J/ψ$ associated production with a bottom quark pair from the Higgs boson decay in next-to-leading order QCD

“…In the past two decades, many works have considered the contribution of higher-order corrections to heavy quarkonium and achieved remarkable successes in phenomenologically(see the review [27] and its references). However, NRQCD still faces challenges, such as the universality of LDMEs [20,28], the kinematic distribution of J/ψ + W ± measured by ATLAS [29,30], and the polarization problem of χ c1 and χ c2 [31] have not been fully explained. In order to study the production mechanism of heavy quarkonium, we should study more the production process of heavy quarkonium at different colliders.…”

Heavy Flavour Physics and CP Violation at LHCb: a Ten-Year Review

“…MPIs are sensitive to correlations between partons in space, momentum, flavour, colour, spin etc. inside the colliding projectiles [136][137][138][139][140][141]. Usually in an MPI process each parton-scattering is assumed to be independent from each other.…”

“…Usually in an MPI process each parton-scattering is assumed to be independent from each other. Under this assumption, the cross-section for associated production of AB through a double-parton-scattering (DPS) process is related to the single inclusive production of A and B as [136] σ…”

“…In the near future, new data will provide enough statistics for associated production of triple heavy flavours and heavy quarkonium pairs beyond J/ψJ/ψ, which help to further understand MPI and heavy quarkonium production mechanism [136]. Concerning studies of nuclear matter effects using heavy-flavour production, a rich program is foreseen in Run 3, including measurements probing the DPS enhancement, the modification of nuclear PDF and heavy-quark fragmentation and the heavy quarkonium dissociation mechanism.…”

A short theoretical review of charmonium production

“…We put stress on charmonium production at hadron colliders, with brief overview of the quarkonium production in e + e − , ep and γγ collisions. We refer the readers to several relevant reviews [1][2][3][4][5] for detailed discussions of other topics in quarkonium physics.…”