Dataset

GSI-2024-00272

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Production of pions, kaons and protons as a function of the transverse event activity in pp collisions at $\sqrt{s}=13$ TeV

ALICE Collaboration (Corresponding author)

2023

Please use a persistent id in citations: doi:10.17182/HEPDATA.140124

Abstract: The production of $\pi^{\pm}$, $\mathrm{K}^{\pm}$, and $(\mathrm{\overline{p}})\mathrm{p}$ is measured in pp collisions at $\sqrt{s}\,= 13~\mathrm{TeV}$ in different topological regions of the events. Particle transverse momentum $(p_{\mathrm{T}})$ spectra are measured in the ``toward'', ``transverse'', and ``away'' angular regions defined with respect to the direction of the leading particle in the event. While the toward and away regions contain the fragmentation products of the near-side and away-side jets, respectively, the transverse region is dominated by particles from the Underlying Event (UE). The relative transverse activity classifier, $R_{\mathrm{T}} = N_{\mathrm{T}} / \langle N_{\mathrm{T}} \rangle$, is used to group events according to their UE activity, where $N_{\mathrm{T}}$ is the measured charged-particle multiplicity per event in the transverse region and $\langle N_{\mathrm{T}} \rangle$ is the mean value over all the analysed events. The first measurements of identified particle $p_{\mathrm{T}}$ spectra as a function of $R_{\mathrm{T}}$ in the three topological regions are reported. It is found that the yield of high transverse momentum particles relative to the $R_{\mathrm{T}}$-integrated measurement decreases with increasing $R_{\mathrm{T}}$ in both the toward and the away regions, indicating that the softer UE dominates particle production as $R_{\mathrm{T}}$ increases and validating that $R_{\mathrm{T}}$ can be used to control the magnitude of the UE. Conversely, the spectral shapes in the transverse region harden significantly with increasing $R_{\mathrm{T}}$. This hardening follows a mass ordering, being more significant for heavier particles. Finally, it is observed that the $p_{\mathrm{T}}$-differential particle ratios $(\mathrm{p} + \mathrm{\overline{p}})/(\pi^{+} + \pi^{-})$ and $(\mathrm{K}^{+} + \mathrm{K}^{-})/(\pi^{+} + \pi^{-})$ in the low UE limit $(R_{\mathrm{T}} \rightarrow 0)$ approach expectations from Monte Carlo generators such as PYTHIA 8 and EPOS LHC, where the jet-fragmentation models have been tuned to reproduce $\mathrm{e}^{+}\mathrm{e}^{-}$ results.

Note: Journal Article GSI record: GSI-2024-00271

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Contributing Institute(s):

1. ALICE (ALI)
2. Detektorlabor (DTL)
3. IT (CIT)
4. ExtreMe Matter Institute, EMMI (EXM)
5. Collaboration CERN: ALICE (ALICE@CERN)

Research Program(s):

1. 612 - Cosmic Matter in the Laboratory (POF4-612) (POF4-612)
2. HGS-HIRe - HGS-HIRe for FAIR (HGS-HIRe) (HGS-HIRe)
3. SUC-GSI-Heidelberg - Strategic university cooperation GSI-U Heidelberg (SUC-GSI-HE) (SUC-GSI-HE)
4. SUC-GSI-Frankfurt - Strategic university cooperation GSI-U Frankfurt/M (SUC-GSI-FR) (SUC-GSI-FR)
5. SUC-GSI-Darmstadt - Strategic university cooperation GSI-TU Darmstadt (SUC-GSI-DA) (SUC-GSI-DA)

Experiment(s):

1. LHC: ALICE

Appears in the scientific report 2023

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Linked articles:

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Journal Article Acharya, S. ; Adamova, D. ; Adler, A. ; et al
Production of pions, kaons, and protons as a function of the relative transverse activity classifier in pp collisions at $ \sqrt{s} $ = 13 TeV
Journal of high energy physics 06(6), 27 (2023) [10.1007/JHEP06(2023)027]2023   Files  Fulltext by arXiv.org BibTeX | EndNote: XML, Text | RIS

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