Toward unbiased flow measurements in LHC proton-proton collisions

Two-particle angular correlations of charged-particle pairs are studied in pp collisions at √s = 13 TeV with four different Monte-Carlo event generators. Correlation functions are constructed with relative azimuthal angle ∆φ and relative pseudorapidity distance ∆η between hadrons such as π, K, p and...

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Bibliographic Details
Main Author: Kallio, Teemu
Other Authors: Matemaattis-luonnontieteellinen tiedekunta, Faculty of Sciences, Fysiikan laitos, Department of Physics, Jyväskylän yliopisto, University of Jyväskylä
Format: Master's thesis
Language:eng
Published: 2024
Subjects:
Online Access: https://jyx.jyu.fi/handle/123456789/99156
Description
Summary:Two-particle angular correlations of charged-particle pairs are studied in pp collisions at √s = 13 TeV with four different Monte-Carlo event generators. Correlation functions are constructed with relative azimuthal angle ∆φ and relative pseudorapidity distance ∆η between hadrons such as π, K, p and Λ particle pairs in multiple ∆η intervals. Using the low-multiplicity template fit method, enhanced jet yields in high-multiplicity events with respect to low-multiplicity events are subtracted. Due to a kinematic bias from jets and the difference in how event generators implement jet and flow components, subtraction of non-flow bias results in small systems. With a multiphase transport (AMPT) string melting model mass ordering of the extracted flow coefficients at low-pT and particle type grouping at high-pT ranges was observed. However, these characteristics are found to be different from results observed in large systems.