Search results for "Heavy ion experiments"

showing 3 items of 43 documents

Event-shape and multiplicity dependence of freeze-out radii in pp collisions at √s = 7 TeV

2019

Two-particle correlations in high-energy collision experiments enable the extraction of particle source radii by using the Bose-Einstein enhancement of pion production at low relative momentum q ∝ 1/R. It was previously observed that in pp collisions at s√ = 7TeV the average pair transverse momentum kT range of such analyses is limited due to large background correlations which were attributed to mini-jet phenomena. To investigate this further, an event-shape dependent analysis of Bose-Einstein correlations for pion pairs is performed in this work. By categorizing the events by their transverse sphericity ST into spherical (ST > 0:7) and jet-like (ST < 0:3) events a method was developed tha…

particle correlations and fluctuationsNuclear and High Energy Physicsionithiukkasfysiikkaheavy ion experiments
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Study of very forward energy and its correlation with particle production at midrapidity in pp and p-Pb collisions at the LHC

2022

Journal of high energy physics 08(8), 86 (2022). doi:10.1007/JHEP08(2022)086

perturbation theory [quantum chromodynamics]p p: scatteringNuclear and High Energy Physics:Kjerne- og elementærpartikkelfysikk: 431 [VDP]FOS: Physical scienceshiukkasfysiikkatransverse momentum[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex]530114 Physical sciencesHigh Energy Physics - ExperimentHigh Energy Physics - Experiment (hep-ex)ALICEHeavy Ion Experimentsscattering [p p]Heavy Ion Experiments ; calorimeter: forward spectrometer ; p: fragmentation ; quantum chromo ; dynamics: perturbation theory ; pp: scattering ; p nucleus: scattering ; parton: interaction ; CERN LHC Coll ; PYTHIA ; correlation ; Monte Carlo ; underlying event ; ALICE ; transverse momentum ; rapidity ; experimental results ; 13000 GeV-cms/nucleon ; 8160 GeV-cms/nucleon[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]Nuclear Physics - Experimentddc:530p: fragmentationquantum chromodynamics: perturbation theoryNuclear Experiment (nucl-ex)parton: interactionNuclear ExperimentNuclear Experimentp nucleus: scatteringMonte Carlointeraction [parton]calorimeter: forward spectrometerunderlying eventscattering [p nucleus]8160 GeV-cms/nucleonfragmentation [p]forward spectrometer [calorimeter]:Nuclear and elementary particle physics: 431 [VDP]CERN LHC Collrapiditycorrelation13000 GeV-cms/nucleonPYTHIAParticle Physics - Experimentexperimental results
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Jet fragmentation transverse momentum distributions in pp and p-Pb collisions at √s, √sNN = 5.02 TeV

2021

Jet fragmentation transverse momentum (jT) distributions are measured in proton-proton (pp) and proton-lead (p-Pb) collisions at √sNN = 5.02 TeV with the ALICE experiment at the LHC. Jets are reconstructed with the ALICE tracking detectors and electromagnetic calorimeter using the anti-kT algorithm with resolution parameter R = 0.4 in the pseudorapidity range |η| < 0.25. The jT values are calculated for charged particles inside a fixed cone with a radius R = 0.4 around the reconstructed jet axis. The measured jT distributions are compared with a variety of parton-shower models. Herwig and Pythia 8 based models describe the data well for the higher jT region, while they underestimate the low…

related to the perturbative component of the fragmentation processthe measured trends are successfully described by all models except for Herwig. For the wide componentHerwig and PYTHIA 8 based models slightly underestimate the data for the higher jet transverse momentum region. These measurements set constraints on models of jet fragmentation and hadronisation.Nuclear and High Energy Physicswhile that of the inverse gamma function increases with increasing jet transverse momentum. For the narrow componentHeavy Ion Experimentsand with a Gaussian for lower jT values (called the “narrow component”)hiukkasfysiikkawhile they underestimate the lower jT region. The jT distributions are further characterised by fitting them with a function composed of an inverse gamma function for higher jT values (called the “wide component”)predominantly connected to the hadronisation process. The width of the Gaussian has only a weak dependence on jet transverse momentumJet fragmentation transverse momentum (jT) distributions are measured in proton-proton (pp) and proton-lead (p-Pb) collisions at √sNN = 5.02 TeV with the ALICE experiment at the LHC. Jets are reconstructed with the ALICE tracking detectors and electromagnetic calorimeter using the anti-kT algorithm with resolution parameter R = 0.4 in the pseudorapidity range |η| < 0.25. The jT values are calculated for charged particles inside a fixed cone with a radius R = 0.4 around the reconstructed jet axis. The measured jT distributions are compared with a variety of parton-shower models. Herwig and PYTHIA 8 based models describe the data well for the higher jT region
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