Measurement of the ${\eta }_c(1S)$ production cross-section in $pp$ collisions at $\sqrt{s}=13$ TeV

Abstract

Using a data sample corresponding to an integrated luminosity of $2.0f{b}^{-1}$, collected by the LHCb experiment, the production of the ${\eta }_c(1S)$ state in proton-proton collisions at a centre-of-mass energy of $\sqrt{s}=13\text{ TeV}$ is studied in the rapidity range $2.0<y<4.5$ and in the transverse momentum range $6.5<p_T<14.0\text{ GeV}$. The cross-section for prompt production of ${\eta }_c(1S)$ mesons relative to that of the $J/\psi$ meson is measured using the $p\bar{p}$ decay mode and is found to be ${\sigma }_{{\eta }_c(1S)}/{\sigma }_{J/\psi }=1.69\pm 0.15\pm 0.10\pm 0.18$. The quoted uncertainties are, in order, statistical, systematic and due to uncertainties on the branching fractions of the $J/\psi \to p\bar{p}$ and ${\eta }_c\to p\bar{p}$ decays. The prompt ${\eta }_c(1S)$ production cross-section is determined to be ${\sigma }_{{\eta }_c(1S)}=1.26\pm 0.11\pm 0.08\pm 0.14\mu b$, where the last uncertainty includes that on the $J/\psi$ meson cross-section. The ratio of the branching fractions of $b$-hadron decays to the ${\eta }_c(1S)$ and $J/\psi$ states is measured to be ${\mathcal{B}}_{b\to {\eta }_{c}X}/{\mathcal{B}}_{b\to J/\psi X}=0.48\pm 0.03\pm 0.03\pm 0.05$, where the last uncertainty is due to those on the branching fractions of the $J/\psi \to p\bar{p}$ and ${\eta }_c\to p\bar{p}$ decays. The difference between the $J/\psi$ and ${\eta }_c(1S)$ masses is also determined to be $113.0\pm 0.7\pm 0.1\text{ MeV}$, which is the most precise single measurement of this quantity to date.

All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2019-024.html (LHCb public pages)

References in corpus (9)

• PYTHIA 6.4 Physics and Manual
• ${\eta }_c$ production at the LHC challenges nonrelativistic-QCD factorization
• Impact of ${\eta }_c$ hadroproduction data on charmonium production and polarization within NRQCD framework
• ${\eta }_c$ production at LHC and indications on the understanding of $J/\psi$ production
• Measurement of $\psi (2S)$ polarisation in $pp$ collisions at $\sqrt{s}=7$ TeV
• Measurement of J/psi production in pp collisions at sqrt(s)=2.76 TeV
• Phenomenological NLO analysis of eta(c) production at the LHC in the collider and fixed-target modes
• Production of ${\eta }_Q$ meson at LHC
• Energy Dependence of Direct-Quarkonium Production in pp Collisions from Fixed-Target to LHC Energies: Complete One-Loop Analysis

Cited by in corpus (18)

• Heavy Flavour Physics and CP Violation at LHCb: a Ten-Year Review
• Quarkonium spectroscopy of the linear plus modified Yukawa potential
• ${\eta }_c$-nucleus bound states
• Prospects for quarkonium studies at the high-luminosity LHC
• Study of charmonium decays to $K_S^{0}K\pi$ in the $B\to (K_S^{0}K\pi )K$ channels
• Fragmentation of fully heavy tetraquarks: The TQ4Q1.1 functions as a case study
• Hard diffractive ${\eta }_{\mathrm{c},\mathrm{b}}$ hadroproduction at the LHC
• Central exclusive production of scalar and pseudoscalar charmonia in the light-front $k_T$-factorization approach
• Pseudoscalar heavy-quarkonium hadroproduction from nonrelativistic fragmentation at NLL/NLO${}^{+}$
• Resummation of threshold double logarithms in hadroproduction of heavy quarkonium
• Predictions for $h_c$ and $h_b$ production at the LHC
• Inclusive diffractive ${\eta }_{\mathrm{c}}$ production in pp, pA and AA modes at the LHC
• Production of $S$-wave charmonia in the soft gluon resummation approach using the NRQCD
• Inclusive production of heavy quarkonium ${\eta }_Q$ via $Z$ boson decays within the framework of nonrelativistic QCD
• Study of charmonium production via the decay to $p\bar{p}$ at $\sqrt{s}=13TeV$
• A new parton fragmentation procedure for heavy hadron production in proton-proton collisions
• All-charm tetraquarks at hadron colliders: A high-precision fragmentation perspective
• Can Transverse Mass Scaling Shed Light on the Event-Activity Dependence of ${\rm Y}$ Mesons Production at LHC?