Factorization of two-particle distributions measured in Pb-Pb collisions at √sNN = 5.02TeV with the ALICE detector

Christian Alexander Bourjau

Factorization of two-particle distributions measured in Pb-Pb collisions at √^sNN = 5.02TeV with the ALICE detector

Christian Alexander Bourjau

Abstract

The angular distribution of particles produced in relativistic heavy-ion collisions is commonly described in terms of their complex ow coecients Vn(; pT). This description implicitly assumes that two-particle distributions of a single collision can be described by the product of the complex ow coecients; a property commonly referred to as factorization. The amplitude and phase of the coecients uctuate event-by-event and thereby break the factorization assumption for distributions which are averaged over many events. Additionally, factorization may also be broken by non- ow processes such as di-jets. This analysis studies the factorization of sample-average two-particle distributions in the (a; b)-plane in Pb{Pb collisions at psNN = 5:02TeV. The analysis is performed over the large pseudorapidity range of 􀀀3 < < 5 by combining the Forward Multiplicity Detector (FMD) and the Inner Tracking System (ITS) of the ALICE detector in a novel analysis method. The original factorization assumption is found to hold for particle pairs with a minimal longitudinal separation of min = 2:6 0:2. A modied factorization assumption which accounts for a jj-dependent attenuation of the two-particle Fourier coecients due to uctuations is also investigated. The attenuation eect is quantied by the empirical parameter F 2 which is found to be in agreement with previous CMS observation at psNN = 2:76TeV as well as with AMPT model calculations

Original language	English

Publisher	The Niels Bohr Institute, Faculty of Science, University of Copenhagen
Publication status	Published - 2018

Access to Document

PhD-BourjauFinal published version, 10.8 MB

https://rex.kb.dk/primo-explore/fulldisplay?docid=KGL01011893756&context=L&vid=NUI&search_scope=KGL&tab=default_tab&lang=da_DK

Cite this

@phdthesis{2585ae6fe24e4818b7b920db40e97c6e,

title = "Factorization of two-particle distributions measured in Pb-Pb collisions at √sNN = 5.02TeV with the ALICE detector",

abstract = "The angular distribution of particles produced in relativistic heavy-ion collisions is commonly described in terms of their complex ow coecients Vn(; pT). This description implicitly assumes that two-particle distributions of a single collision can be described by the product of the complex ow coecients; a property commonly referred to as factorization. The amplitude and phase of the coecients uctuate event-by-event and thereby break the factorization assumption for distributions which are averaged over many events. Additionally, factorization may also be broken by non- ow processes such as di-jets. This analysis studies the factorization of sample-average two-particle distributions in the (a; b)-plane in Pb{Pb collisions at psNN = 5:02TeV. The analysis is performed over the large pseudorapidity range of 􀀀3 < < 5 by combining the Forward Multiplicity Detector (FMD) and the Inner Tracking System (ITS) of the ALICE detector in a novel analysis method. The original factorization assumption is found to hold for particle pairs with a minimal longitudinal separation of min = 2:6 0:2. A modied factorization assumption which accounts for a jj-dependent attenuation of the two-particle Fourier coecients due to uctuations is also investigated. The attenuation eect is quantied by the empirical parameter F 2 which is found to be in agreement with previous CMS observation at psNN = 2:76TeV as well as with AMPT model calculations",

author = "Bourjau, {Christian Alexander}",

year = "2018",

language = "English",

publisher = "The Niels Bohr Institute, Faculty of Science, University of Copenhagen",

}

TY - BOOK

T1 - Factorization of two-particle distributions measured in Pb-Pb collisions at √sNN = 5.02TeV with the ALICE detector

AU - Bourjau, Christian Alexander

PY - 2018

Y1 - 2018

N2 - The angular distribution of particles produced in relativistic heavy-ion collisions is commonly described in terms of their complex ow coecients Vn(; pT). This description implicitly assumes that two-particle distributions of a single collision can be described by the product of the complex ow coecients; a property commonly referred to as factorization. The amplitude and phase of the coecients uctuate event-by-event and thereby break the factorization assumption for distributions which are averaged over many events. Additionally, factorization may also be broken by non- ow processes such as di-jets. This analysis studies the factorization of sample-average two-particle distributions in the (a; b)-plane in Pb{Pb collisions at psNN = 5:02TeV. The analysis is performed over the large pseudorapidity range of 􀀀3 < < 5 by combining the Forward Multiplicity Detector (FMD) and the Inner Tracking System (ITS) of the ALICE detector in a novel analysis method. The original factorization assumption is found to hold for particle pairs with a minimal longitudinal separation of min = 2:6 0:2. A modied factorization assumption which accounts for a jj-dependent attenuation of the two-particle Fourier coecients due to uctuations is also investigated. The attenuation eect is quantied by the empirical parameter F 2 which is found to be in agreement with previous CMS observation at psNN = 2:76TeV as well as with AMPT model calculations

AB - The angular distribution of particles produced in relativistic heavy-ion collisions is commonly described in terms of their complex ow coecients Vn(; pT). This description implicitly assumes that two-particle distributions of a single collision can be described by the product of the complex ow coecients; a property commonly referred to as factorization. The amplitude and phase of the coecients uctuate event-by-event and thereby break the factorization assumption for distributions which are averaged over many events. Additionally, factorization may also be broken by non- ow processes such as di-jets. This analysis studies the factorization of sample-average two-particle distributions in the (a; b)-plane in Pb{Pb collisions at psNN = 5:02TeV. The analysis is performed over the large pseudorapidity range of 􀀀3 < < 5 by combining the Forward Multiplicity Detector (FMD) and the Inner Tracking System (ITS) of the ALICE detector in a novel analysis method. The original factorization assumption is found to hold for particle pairs with a minimal longitudinal separation of min = 2:6 0:2. A modied factorization assumption which accounts for a jj-dependent attenuation of the two-particle Fourier coecients due to uctuations is also investigated. The attenuation eect is quantied by the empirical parameter F 2 which is found to be in agreement with previous CMS observation at psNN = 2:76TeV as well as with AMPT model calculations

UR - https://rex.kb.dk/primo-explore/fulldisplay?docid=KGL01011893756&context=L&vid=NUI&search_scope=KGL&tab=default_tab&lang=da_DK

M3 - Ph.D. thesis

BT - Factorization of two-particle distributions measured in Pb-Pb collisions at √sNN = 5.02TeV with the ALICE detector

PB - The Niels Bohr Institute, Faculty of Science, University of Copenhagen

ER -

Factorization of two-particle distributions measured in Pb-Pb collisions at √^sNN = 5.02TeV with the ALICE detector

Abstract

Access to Document

Other files and links

Fingerprint

Cite this