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Studying possible higher twist contributions in the inclusive charged hadron cross sections

In the standard pQCD picture particles are produced via the parton jet fragmentation process. However, there are also other production mechanisms like higher twist (HT) processes. A usual example of a HT process is a direct production of an outgoing hadron, where the hadron is produced in the hard s...

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Autor principal: Pohjoisaho, Esko
Lenguaje:eng
Publicado: 2014
Materias:
Acceso en línea:https://dx.doi.org/10.1088/1742-6596/589/1/012016
http://cds.cern.ch/record/1743335
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author Pohjoisaho, Esko
author_facet Pohjoisaho, Esko
author_sort Pohjoisaho, Esko
collection CERN
description In the standard pQCD picture particles are produced via the parton jet fragmentation process. However, there are also other production mechanisms like higher twist (HT) processes. A usual example of a HT process is a direct production of an outgoing hadron, where the hadron is produced in the hard subprocess without fragmentation. We study the HT phenomena using a shape analysis (x(T) scaling) of the inclusive invariant cross sections of charged hadrons, measured by the ALICE collaboration at center-of-mass energies = 2.76 TeV and 7 TeV. The data is compared to PYTHIA8 event generator and to a phenomenological model for HT. Using PYTHIA8, we explore a possible enhancement of HT phenomena for isolated particles, by comparing the shapes of the isolated distributions to inclusive distributions. The results from the standard PYTHIA8, without HT, is compared to a PYTHIA8 where we had included a HT process. Finally, we found out that the effects observed in the x(T) spectra originate from kinematic biases posed by the isolation cuts, rather than from an enrichment of the HT hadrons at the observed cross sections. A more detailed data analysis is ongoing.
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institution Organización Europea para la Investigación Nuclear
language eng
publishDate 2014
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spelling cern-17433352021-07-15T17:35:36Zdoi:10.1088/1742-6596/589/1/012016http://cds.cern.ch/record/1743335engPohjoisaho, EskoStudying possible higher twist contributions in the inclusive charged hadron cross sectionshep-exParticle Physics - ExperimentParticle Physics - PhenomenologyIn the standard pQCD picture particles are produced via the parton jet fragmentation process. However, there are also other production mechanisms like higher twist (HT) processes. A usual example of a HT process is a direct production of an outgoing hadron, where the hadron is produced in the hard subprocess without fragmentation. We study the HT phenomena using a shape analysis (x(T) scaling) of the inclusive invariant cross sections of charged hadrons, measured by the ALICE collaboration at center-of-mass energies = 2.76 TeV and 7 TeV. The data is compared to PYTHIA8 event generator and to a phenomenological model for HT. Using PYTHIA8, we explore a possible enhancement of HT phenomena for isolated particles, by comparing the shapes of the isolated distributions to inclusive distributions. The results from the standard PYTHIA8, without HT, is compared to a PYTHIA8 where we had included a HT process. Finally, we found out that the effects observed in the x(T) spectra originate from kinematic biases posed by the isolation cuts, rather than from an enrichment of the HT hadrons at the observed cross sections. A more detailed data analysis is ongoing.In the standard pQCD picture particles are produced via the parton jet fragmentation process. However, there are also other production mechanisms like higher twist (HT) processes. A usual example of a HT process is a direct production of an outgoing hadron, where the hadron is produced in the hard subprocess without fragmentation. We study the HT phenomena using a shape analysis (xT scaling) of the inclusive invariant cross sections of charged hadrons, measured by the ALICE collaboration at center-of-mass energies \sqrt{s}=2.76 TeV and 7 TeV. The data is compared to PYTHIA8 event generator and to a phenomenological model for HT. Using PYTHIA8, we explore a possible enhancement of HT phenomena for isolated particles, by comparing the shapes of the isolated distributions to inclusive distributions. The results from the standard PYTHIA8, without HT, is compared to a PYTHIA8 where we had included a HT process. Finally, we found out that the effects observed in the xT spectra originate from kinematic biases posed by the isolation cuts, rather than from an enrichment of the HT hadrons at the observed cross sections. A more detailed data analysis is ongoing.arXiv:1407.3691oai:cds.cern.ch:17433352014-07-14
spellingShingle hep-ex
Particle Physics - Experiment
Particle Physics - Phenomenology
Pohjoisaho, Esko
Studying possible higher twist contributions in the inclusive charged hadron cross sections
title Studying possible higher twist contributions in the inclusive charged hadron cross sections
title_full Studying possible higher twist contributions in the inclusive charged hadron cross sections
title_fullStr Studying possible higher twist contributions in the inclusive charged hadron cross sections
title_full_unstemmed Studying possible higher twist contributions in the inclusive charged hadron cross sections
title_short Studying possible higher twist contributions in the inclusive charged hadron cross sections
title_sort studying possible higher twist contributions in the inclusive charged hadron cross sections
topic hep-ex
Particle Physics - Experiment
Particle Physics - Phenomenology
url https://dx.doi.org/10.1088/1742-6596/589/1/012016
http://cds.cern.ch/record/1743335
work_keys_str_mv AT pohjoisahoesko studyingpossiblehighertwistcontributionsintheinclusivechargedhadroncrosssections