Investigating the most active pp collisions (top 0.1%) using the tools developed by experiments at the LHC

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Méndez, Jesús Eduardo Muñoz, Ortiz, Antonio
Format: Preprint
Publié: 2025
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866917300122157056
author Méndez, Jesús Eduardo Muñoz
Ortiz, Antonio
author_facet Méndez, Jesús Eduardo Muñoz
Ortiz, Antonio
contents The LHC data have unveiled unexpected features in proton-proton (pp) collisions, namely, collective-like behavior and strangeness enhancement. Originally, these new effects were discovered only in high-multiplicity pp collisions. However, recently the ALICE Collaboration has shown that even low-multiplicity pp collisions yield a non-zero elliptic flow ($v_{2}$). Moreover, analyses as functions of the event structure, such as transverse spherocity, suggest that multiplicity might not be the main driver of the new effects. Therefore, new ways of analyzing the data have to be explored in order to understand the origin of the new phenomena. In this paper, pp collisions simulated with PYTHIA 8 are analyzed using different event estimators (mid-pseudorapidity multiplicity, spherocity, sphericity, $R_T$, forward multiplicity and flattenicity). The features of the selected events for the top 0.1% using the different estimators are discussed. The transverse momentum spectrum of primary particles and the recoil jet distributions are analyzed. The results suggest that flattenicity is the estimator with the least bias on the neutral-to-charged particle ratio, and on the bias towards harder-than-average pp collisions.
format Preprint
id arxiv_https___arxiv_org_abs_2506_06588
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Investigating the most active pp collisions (top 0.1%) using the tools developed by experiments at the LHC
Méndez, Jesús Eduardo Muñoz
Ortiz, Antonio
High Energy Physics - Phenomenology
The LHC data have unveiled unexpected features in proton-proton (pp) collisions, namely, collective-like behavior and strangeness enhancement. Originally, these new effects were discovered only in high-multiplicity pp collisions. However, recently the ALICE Collaboration has shown that even low-multiplicity pp collisions yield a non-zero elliptic flow ($v_{2}$). Moreover, analyses as functions of the event structure, such as transverse spherocity, suggest that multiplicity might not be the main driver of the new effects. Therefore, new ways of analyzing the data have to be explored in order to understand the origin of the new phenomena. In this paper, pp collisions simulated with PYTHIA 8 are analyzed using different event estimators (mid-pseudorapidity multiplicity, spherocity, sphericity, $R_T$, forward multiplicity and flattenicity). The features of the selected events for the top 0.1% using the different estimators are discussed. The transverse momentum spectrum of primary particles and the recoil jet distributions are analyzed. The results suggest that flattenicity is the estimator with the least bias on the neutral-to-charged particle ratio, and on the bias towards harder-than-average pp collisions.
title Investigating the most active pp collisions (top 0.1%) using the tools developed by experiments at the LHC
topic High Energy Physics - Phenomenology
url https://arxiv.org/abs/2506.06588