$J/\psi$ meson production in association with an open charm hadron at the LHC: A reappraisal

Abstract

We critically (re)examine the associated production process of a $J/\psi$ meson plus an open charm hadron at the LHC in the proton-proton ($pp$) and proton-lead ($p\mathrm{Pb}$) collisions. Such a process is very intriguing in the sense of tailoring to explore the double parton structure of nucleons and to determine the geometry of partons in nuclei. In order to interpret the existing $pp$ data with the LHCb detector at the center-of-mass energy $\sqrt{s}=7$ TeV, we introduce two overlooked mechanisms for the double parton scattering (DPS) and single parton scattering (SPS) processes. Besides the conventional DPS mode, where the two mesons are produced almost independently in the two separate scattering subprocesses, we propose a novel DPS mechanism that the two constituent (heavy) quarks stemming from two hard scatterings can form into a composite particle, like the $J/\psi$ meson, during the hadronization phase. However, it turns out the corresponding contribution is small in $J/\psi +c\bar{c}$ hadroproduction. On the contrary, we point out that the resummation of the initial state logarithms due to gluon splitting into a charm quark pair is crucial to understand the LHCb measurement, which was overlooked in the literature. We perform a proper matching between the perturbative calculations in different initial-quark flavor number schemes, generically referring to the variable flavor number scheme. The new variable flavor number scheme calculation for the process strongly enhance the SPS cross sections, almost closing the discrepancies between theory and experiment. Finally, we present our predictions for the forthcoming LHCb measurement in $p\mathrm{Pb}$ collisions at $\sqrt{s_{NN}}=8.16$ TeV. Some interesting observables are exploited to set up the control regions of the DPS signal and to probe the impact-parameter dependent parton densities in lead.

32 pages, 20 figures, 7 tables; v2: match to journal version (add a new figure and a few references, fix a few typos)

References in corpus (15)

• An Introduction to PYTHIA 8.2
• New parton distributions for collider physics
• Parton distributions in the LHC era: MMHT 2014 PDFs
• Towards an automated tool to evaluate the impact of the nuclear modification of the gluon density on quarkonium, D and B meson production in proton-nucleus collisions
• Polarization for Prompt J/psi, psi(2s) production at the Tevatron and LHC
• High transverse momentum quarkonium production and dissociation in heavy ion collisions
• Hadroproduction of J/psi and Upsilon in association with a heavy-quark pair
• ${\eta }_c$ production at LHC and indications on the understanding of $J/\psi$ production
• Color Transfer in Associated Heavy-Quarkonium Production
• Associated production of a quarkonium and a Z boson at one loop in a quark-hadron-duality approach
• Triple prompt $J/\psi$ hadroproduction as a hard probe of multiple-parton scatterings
• Determination of the strong coupling constant ${\alpha }_s(m_Z)$ from measurements of the total cross section for top-antitop quark production
• Color Transfer Enhancement for Heavy Quarkonium Production
• Heavy Quark Production in the ACOT Scheme at NNLO and N3LO
• ${\chi }_{cJ}$ production associated with a $c\bar{c}$ pair at hadron colliders

Cited by in corpus (10)

• Large-P_T inclusive photoproduction of J/psi in electron-proton collisions at HERA and the EIC
• Reweighted nuclear PDFs using Heavy-Flavor Production Data at the LHC: nCTEQ15_rwHF & EPPS16_rwHF
• Heavy Flavour Physics and CP Violation at LHCb: a Ten-Year Review
• Observation of enhanced double parton scattering in proton-lead collisions at $\sqrt{s_{\mathrm{NN}}}=8.16$ TeV
• Prospects for quarkonium studies at the high-luminosity LHC
• Measurement of $J/\psi$-pair production in $pp$ collisions at $\sqrt{s}=13$ TeV and study of gluon transverse-momentum dependent PDFs
• Associated production of heavy quarkonium and $D-$meson in the improved color evaporation model with KaTie
• Associated production of prompt $J/\psi$ and ${\rm Y}$ mesons in $pp$ collisions at $\sqrt{s}=13\mathrm{TeV}$
• FKS subtraction for quarkonium production at NLO
• Automated event generation for S-wave quarkonium and leptonium production in NRQCD and NRQED