Measurement of the multiplicity dependence of $\mitΥ$ production ratios in $pp$ collisions at $\sqrt{s}=13$ TeV

Abstract

The $\mitΥ(\mathrm{2}S)$ and $\mitΥ(\mathrm{3}S)$ production cross-sections are measured relative to that of the $\mitΥ(\mathrm{1}S)$ meson, as a function of charged-particle multiplicity in proton-proton collisions at a centre-of-mass energy of $13$ TeV. The measurement uses data collected by the LHCb experiment in 2018 corresponding to an integrated luminosity of 2 ${\text{fb}}^{-1}$. Both the $\mitΥ(\mathrm{2}S)$-to-$\mitΥ(\mathrm{1}S)$ and $\mitΥ(\mathrm{3}S)$-to-$\mitΥ(\mathrm{1}S)$ cross-section ratios are found to decrease significantly as a function of event multiplicity, with the $\mitΥ(\mathrm{3}S)$-to-$\mitΥ(\mathrm{1}S)$ ratio showing a steeper decline towards high multiplicity. This hierarchy is qualitatively consistent with the comover model predictions, indicating that final-state interactions play an important role in bottomonia production in high-multiplicity events.

All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://lbfence.cern.ch/alcm/public/analysis/full-details/1782/ (LHCb public pages)

References in corpus (6)

• PYTHIA 6.4 Physics and Manual
• The order of the quantum chromodynamics transition predicted by the standard model of particle physics
• EPS09 - a New Generation of NLO and LO Nuclear Parton Distribution Functions
• Color Screening Melts Quarkonium
• Multiple scattering effects on heavy meson production in p+A collisions at backward rapidity
• Quarkonium suppression in heavy-ion collisions from coherent energy loss in cold nuclear matter