G5 Doctoral dissertation (article)
Simulation of quark-gluon plasma initial states with Monte-Carlo EKRT model (2024)
Kvarkki-gluoniplasman alkutilansimulointikäyttäenMonte-CarloEKRT-mallia

Kuha, M. (2024). Simulation of quark-gluon plasma initial states with Monte-Carlo EKRT model [Doctoral dissertation]. University of Jyväskylä. JYU Dissertations, 834. https://urn.fi/URN:ISBN:978-952-86-0330-6

JYU authors or editors

Publication details

All authors or editors: Kuha, Mikko

eISBN: 978-952-86-0330-6

Journal or series: JYU Dissertations

eISSN: 2489-9003

Publication year: 2024

Number in series: 834

Number of pages in the book: 1 verkkoaineisto (86 sivua, 48 sivua useina numerointijaksoina, 3 numeroimatonta sivua)

Publisher: University of Jyväskylä

Publication country: Finland

Publication language: English

Persistent website address: https://urn.fi/URN:ISBN:978-952-86-0330-6

Publication open access: Openly available

Publication channel open access: Open Access channel

Abstract

In this thesis, the initial state of the quark gluon plasma (QGP) generated in ultrarelativistic heavy-ion collisions is studied. For this purpose, the author has created from scratch a completely new Monte-Carlo (MC) implementation of the successful Eskola-Kajantie-Ruuskanen-Tuominen (EKRT) initial state model. In this model, the energy density generated in the heavy-ion collision is modelled via minijets, small-down to 1 GeV-transverse momentum pT quarks and gluons, produced via perturbative Quantum Chromodynamics (pQCD). A key ingredient is the saturation conjecture, here a local version which fluctuates eventby- event (EbyE), which dynamically controls the generated minijet multiplicity. Among the EbyE fluctuating minijet production, the most important new feature of the model is the rapidity dependence of the output. As the four-momentum of the minijets is fully known, the EbyE fluctuating energy–momentum tensor Tμν of the QGP initial state can be computed, enabling 3+1D fluid dynamical simulations producing rapidity dependent observables. Another novel feature are the developed parton distribution functions (PDFs) which include spatial dependence in nuclear shadowing in a new way that allows also for the largest density fluctuations in the nuclear matter. Also energy conservation and valence quark number conservation are now considered. Among its other features, the new MC-EKRT event generator includes also a nucleon substructure model and the tracking of the partonic flavour of the generated minijets. The heart of the MC-EKRT event generator, the calculation of the inclusive pQCD cross section of producing two jets in a nucleon–nucleon collision σjet with nuclear shadowing, is employed in the article [PI] to investigate the possibility of the need to account for nuclear shadowing in Monte-Carlo Glauber models by using recent experimental data on heavy vector boson production at the LHC as constraints. The article [PII] introduces the MC-EKRT model in detail. The articles [PII] and [PIII] demonstrate the usage of the MC-EKRT initial states in a centrality-class averaged 3+1D hydrodynamical simulation ([PII]) and in boost independent 2+1D EbyE fluid simulation ([PIII]), yielding excellent agreement with the experimental data in the observed rapidity distributions of the charged particle multiplicity dNch/dη in Pb+Pb collisions at √sNN = 5.02 and 2.76 TeV, and in Au+Au collisions at √sNN = 200 GeV, and in their corresponding observed flow coefficients vn.

Keywords: particle physics; ions; collision; quark-gluon plasma; modelling (representation); Monte Carlo methods; quantum chromodynamics; doctoral dissertations

Free keywords: heavy-ion collision; Monte-Carlo simulation; EKRT model; perturbative QCD; quark-gluon plasma; saturation; rapidity distributions; minijets

Contributing organizations

Related projects

Ministry reporting: Yes

VIRTA submission year: 2024