Type
Text
Type
Dissertation
Advisor
Jia, Jiangyong | Lacey, Roy A | Sears, Trevor | Teaney, Derek.
Date
2014-12-01
Keywords
Beam Energy Scan, Critical End Point, HBT, Heavy-ion, nuclear physics, PHENIX | Nuclear physics
Department
Department of Chemistry.
Language
en_US
Source
This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree.
Identifier
http://hdl.handle.net/11401/77136
Publisher
The Graduate School, Stony Brook University: Stony Brook, NY.
Format
application/pdf
Abstract
The primary goal of high-energy nuclear physics is to develop a thorough understanding of the QCD phase diagram: Its different phases, their boundaries, and the physics they define. Heavy-ion collisions reproduce at a microscale the conditions necessary to initiate the phase transitions of nuclear matter that are only possible at extreme temperatures (T) and baryon chemical potential (\mu_{B}). An important probe utilized in studies of the hot and dense matter created in heavy-ion collisions is the method of Hanbury-Brown and Twiss interferometry. The technique is useful in providing measurements in space and time of the pion emission sources at freeze-out. One enduring question of interest in studies of the QCD phase diagram is the position in T and \mu_{B} coordinates of the QCD Critical End Point (CEP) as well as the onset of deconfinement, as predicted by model calculations. According to these models, the Equation of State (EoS) should soften in the vicinity of the CEP and/or a first order phase transition. The expanding hot and dense system is sensitive to changes in the EoS. A softening of the EoS will therefore be reflected in measurements of the final size in space-time of the pion emission source. Another question is how small can a system be before we see a turn-off of hydrodynamically driven final-state effects. In this thesis, detailed HBT measurements obtained using the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC) are presented for three beam collision energies (\sqrt{s_{NN}} = 39, 62, and 200 GeV) and three collision species (d+Au, Cu+Cu, and Au+Au). The measurements are studied for their dependence on collision geometry and transverse mass (m_{T}), and observations are made on how the small asymmetric system, d+Au, compares to the A+A systems for these dependencies. In addition, newly observed universal scaling patterns with the initial transverse size, \bar{R}, and 1/\sqrt{m_{T}} for both RHIC HBT measurements and the Pb+Pb collision system at \sqrt{s_{NN}} = 2.76 TeV are discussed. Finally, observations of non-monotonic behavior in the excitation functions of HBT measurements are presented in detail and their significance reflected on. The results presented here provide a valuable extension to the current understanding of the dynamics of the hot and dense systems produced in heavy-ion collisions. | 130 pages
Recommended Citation
Mwai, Alex Muu, "Beam Energy and System-size Dependence of the Space-time Extent of the Pion Emission Source Produced in Heavy-Ion Collisions" (2014). Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions). 2972.
https://commons.library.stonybrook.edu/stony-brook-theses-and-dissertations-collection/2972