Production of $\eta$ and ${\eta }^{\prime }$ mesons in $pp$ and $p$Pb collisions

Abstract

The production of $\eta$ and ${\eta }^{\prime }$ mesons is studied in proton-proton and proton-lead collisions collected with the LHCb detector. Proton-proton collisions are studied at center-of-mass energies of $5.02$ and $13\mathrm{TeV}$, and proton-lead collisions are studied at a center-of-mass energy per nucleon of $8.16\mathrm{TeV}$. The studies are performed in center-of-mass rapidity regions $2.5<y_{c.m.}<3.5$ (forward rapidity) and $-4.0<y_{c.m.}<-3.0$ (backward rapidity) defined relative to the proton beam direction. The $\eta$ and ${\eta }^{\prime }$ production cross sections are measured differentially as a function of transverse momentum for $1.5<p_{\mathrm{T}}<10\mathrm{GeV}$ and $3<p_{\mathrm{T}}<10\mathrm{GeV}$, respectively. The differential cross sections are used to calculate nuclear modification factors. The nuclear modification factors for $\eta$ and ${\eta }^{\prime }$ mesons agree at both forward and backward rapidity, showing no significant evidence of mass dependence. The differential cross sections of $\eta$ mesons are also used to calculate $\eta /{\pi }^0$ cross section ratios, which show evidence of a deviation from the world average. These studies offer new constraints on mass-dependent nuclear effects in heavy-ion collisions, as well as $\eta$ and ${\eta }^{\prime }$ meson fragmentation.

All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/Publications/p/LHCb-PAPER-2023-030.html (LHCb public pages)

References in corpus (10)

• Observation of long-range near-side angular correlations in proton-lead collisions at the LHC
• Performance of the LHCb Vertex Locator
• Centrality Dependence of pi^0 and eta Production at Large Transverse Momentum in sqrt(s_NN) = 200 GeV d+Au Collisions
• Transverse Single-Spin Asymmetry and Cross-Section for pi0 and eta Mesons at Large Feynman-x in Polarized p+p Collisions at sqrt(s)=200 GeV
• Nuclear effects on the transverse momentum spectra of charged particles in pPb collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV
• Global Analysis of Fragmentation Functions for Eta Mesons
• Measurement of $B^{+}$, $B^0$ and ${\Lambda }_b^0$ production in $p\mathrm{Pb}$ collisions at $\sqrt{s_{\mathrm{NN}}}=8.16\mathrm{TeV}$
• Measurement of the nuclear modification factor and prompt charged particle production in $p\mathrm{Pb}$ and $pp$ collisions at $\sqrt{s_{\mathrm{NN}}}=5\mathrm{TeV}$
• Nuclear modification factor of neutral pions in the forward and backward regions in $p$-Pb collisions
• Proton and pion transverse spectra at RHIC from radial flow and finite size effects

Cited by in corpus (1)

• Global analysis of fragmentation functions to light neutral hadrons