Observation of strangeness enhancement with charmed mesons in high-multiplicity $p\mathrm{Pb}$ collisions at $\sqrt{s_{\mathrm{NN}}}=8.16$TeV

Abstract

The production of prompt $D_s^{+}$ and $D^{+}$ mesons is measured by the LHCb experiment in proton-lead ($p\mathrm{Pb}$) collisions in both the forward ($1.5<y^{\ast }<4.0$) and backward ($-5.0<y^{\ast }<-2.5$) rapidity regions at a nucleon-nucleon center-of-mass energy of $\sqrt{s_{\mathrm{NN}}}=8.16$TeV. The nuclear modification factors of both $D_s^{+}$ and $D^{+}$ mesons are determined as a function of transverse momentum, $p_{\mathrm{T}}$, and rapidity. In addition, the $D_s^{+}$ to $D^{+}$ cross-section ratio is measured as a function of the charged particle multiplicity in the event. An enhanced $D_s^{+}$ to $D^{+}$ production in high-multiplicity events is observed for the whole measured $p_{\mathrm{T}}$ range, in particular at low $p_{\mathrm{T}}$ and backward rapidity, where the significance exceeds six standard deviations. This constitutes the first observation of strangeness enhancement in charm quark hadronization in high-multiplicity $p\mathrm{Pb}$ collisions. The results are also qualitatively consistent with the presence of quark coalescence as an additional charm quark hadronization mechanism in high-multiplicity proton-lead collisions.

All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2023-021.html (LHCb public pages)

References in corpus (13)

• PYTHIA 6.4 Physics and Manual
• Tuning PYTHIA 8.1: the Monash 2013 Tune
• Determination of nuclear parton distribution functions and their uncertainties at next-to-leading order
• 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
• Forward $J/\psi$ production in proton-nucleus collisions at high energy
• Measurement of prompt D-meson production in p-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV
• Charm Hadrons in pp collisions at LHC energy within a Coalescence plus Fragmentation approach
• Unified description of hadron yield ratios from dynamical core-corona initialization
• Observation of $D_s^{\pm }/D^0$ enhancement in Au+Au collisions at $\sqrt{s_{{}_{\mathrm{NN}}}}$ = 200 GeV
• Charm production and fragmentation fractions at midrapidity in pp collisions at $\sqrt{s}=13$ TeV
• Measurement of the prompt $D^0$ nuclear modification factor in $p$Pb collisions at $\sqrt{s_{\mathrm{NN}}}=8.16$ TeV
• Strangeness enhancement across collision systems without a plasma
• Measurement of prompt $D^{+}$ and $D_s^{+}$ production in $p\mathrm{Pb}$ collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$TeV

Cited by in corpus (2)

• Towards the understanding of heavy quarks hadronization: from leptonic to heavy-ion collisions
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