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Title: Particle production as a function of charged-particle flattenicity in pp collisions at s=13 TeV
This paper reports the first measurement of the transverse momentum ( p T ) spectra of primary charged pions, kaons, (anti)protons, and unidentified particles as a function of the charged-particle flattenicity in pp collisions at s = 13 TeV . Flattenicity is a novel event shape observable that is measured in the pseudorapidity intervals covered by the V0 detector, 2.8 < η < 5.1 and 3.7 < η < 1.7 . According to QCD-inspired phenomenological models, it shows sensitivity to multiparton interactions and is less affected by biases toward larger p T due to local multiplicity fluctuations in the V0 acceptance than multiplicity. The analysis is performed in minimum-bias (MB) as well as in high-multiplicity events up to p T = 20 GeV / c . The event selection requires at least one charged particle produced in the pseudorapidity interval | η | < 1 . The measured p T distributions, average p T , kaon-to-pion and proton-to-pion particle ratios, presented in this paper, are compared to model calculations using 8 based on color strings and EPOS LHC. The modification of the p T -spectral shapes in low-flattenicity events that have large event activity with respect to those measured in MB events develops a pronounced peak at intermediate p T ( 2 < p T < 8 GeV / c ), and approaches the vicinity of unity at higher p T . The results are qualitatively described by , and they show different behavior than those measured as a function of charged-particle multiplicity based on the V0M estimator. © 2025 CERN, for the ALICE Collaboration2025CERN  more » « less
Award ID(s):
2208883 2012154
PAR ID:
10599247
Author(s) / Creator(s):
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Corporate Creator(s):
Publisher / Repository:
APS
Date Published:
Journal Name:
Physical Review D
Volume:
111
Issue:
1
ISSN:
2470-0010
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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