Unveiling the effects of multiple soft partonic interactions in pp collisions at $\sqrt{\text{s}}=13.6$ TeV using charged-particle flattenicity

Abstract

Event classifiers based either on the charged-particle multiplicity or the event shape have been extensively used in proton-proton (pp) collisions by the ALICE collaboration at the LHC. The use of these tools became very instrumental since the observation of fluid-like behavior in high-multiplicity pp collisions. In particular, the study as a function of the charged-particle multiplicity registered in the forward V0 ALICE detector allowed for the discovery of strangeness enhancement in high-multiplicity pp collisions. However, one drawback of the multiplicity-based event classifiers is that requiring a high charged-particle multiplicity biases the sample towards hard processes like multi-jet final states. These biases make it difficult to perform jet-quenching searches in high-multiplicity pp collisions. In this context, the present paper explores the use of the new event classifier, flattenicity; which uses the multiplicity calculated in the forward pseudorapidity region. To illustrate how this tool works, pp collisions at $\sqrt{s}=13.6$ TeV simulated with PYTHIA~8 are explored. The sensitivity of flattencity to multi-partonic interactions as well as to the ``hardness'' of the collision are discussed. PYTHIA 8 predictions for the transverse momentum spectra of light- and heavy-flavored hadrons as a function of flattenicity are presented.

10 pages, 10 figures

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Cited by in corpus (10)

• Investigating the soft and hard limits in transverse momentum spectra in pp collisions
• Understanding the transverse-spherocity biased data from pp collisions at the LHC energies
• Particle production as a function of charged-particle flattenicity in pp collisions at $\sqrt{s}$ = 13 TeV
• Probing strangeness with event topology classifiers in pp collisions at energies available at the CERN Large Hadron Collider with the rope hadronization mechanism in PYTHIA
• Investigating radial flow-like effects via pseudorapidity and transverse spherocity dependence of particle production in pp collisions at the LHC
• Flattenicity as "centrality" estimator in p-Pb collisions simulated with PYTHIA 8.312 Angantyr
• Investigating the most active pp collisions (top 0.1%) using the tools developed by experiments at the LHC
• Multiplicity-dependent inclusive J/$\psi$ production at forward rapidity in pp collisions at $\sqrt{\mathbf{s}}=13$ TeV
• Effect of event classification on the Tsallis-thermometer
• Finite $V_{2\Delta }$ puzzle in low-multiplicity pp collisions from ultra-long-range azimuthal correlations in the string-shoving model