Emergence of long-range angular correlations in low-multiplicity proton-proton Collisions

This Letter presents the measurement of near-side associated per-trigger yields, denoted ridge yields, from the analysis of angular correlations of charged hadrons in proton-proton collisions at √=13  TeV. Long-range ridge yields are extracted for pairs of charged particles with a pseudorapidity dif...

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Bibliographic Details
Authors: Acharya, Shreyasi, Gay Ducati, Maria Beatriz, ALICE Collaboration
Format: article
Status:Published version
Publication Date:2024
Country:Brasil
Institution:Universidade Federal do Rio Grande do Sul (UFRGS)
Repository:Repositório Institucional da UFRGS
Language:English
OAI Identifier:oai:www.lume.ufrgs.br:10183/281520
Online Access:http://hdl.handle.net/10183/281520
Access Level:Open access
Keyword:Colisões proton-proton
Colisões hadrônicas
Aceleradores de partículas
Description
Summary:This Letter presents the measurement of near-side associated per-trigger yields, denoted ridge yields, from the analysis of angular correlations of charged hadrons in proton-proton collisions at √=13  TeV. Long-range ridge yields are extracted for pairs of charged particles with a pseudorapidity difference of 1.4<|Δ⁢|<1.8 and a transverse momentum of 1<T<2  GeV/, as a function of the charged-particle multiplicity measured at midrapidity. This Letter extends the measurements of the ridge yield to the low multiplicity region, where in hadronic collisions it is typically conjectured that a strongly interacting medium is unlikely to be formed. The precision of the new low multiplicity results allows for the first direct quantitative comparison with the results obtained in e+⁢e− collisions at √=91  GeV and √=183–209  GeV, where initial-state effects such as preequilibrium dynamics and collision geometry are not expected to play a role. In the multiplicity range 8≲⟨ch⟩≲24 where the e+⁢e− results have good precision, the measured ridge yields in ⁢ collisions are substantially larger than the limits set in e+⁢e− annihilations. Consequently, the findings presented in this Letter suggest that the processes involved in e+⁢e− annihilations do not contribute significantly to the emergence of long-range correlations in ⁢ collisions.