Access Type
Open Access Dissertation
Date of Award
January 2014
Degree Type
Dissertation
Degree Name
Ph.D.
Department
Physics and Astronomy
First Advisor
Sergei Voloshin
Abstract
Since 2009, the Large Hadron Collider (LHC) at European Organization
for Nuclear Research (CERN) has been conducting experiments in $pp$,
Pb-Pb, as well as $p$-Pb collisions with the center of mass energy
ranging $\sqrt{{s}_{NN}}=0.9-5.05$~TeV. In this thesis, both,
estimates of background correlations in anisotropic flow, $v_1-v_5$,
measurements
in Pb-Pb collisions at
$\sqrt{{s}_{NN}}=2.76$~TeV, and azimuthally differential pion femtoscopy
of Pb-Pb collisions are reported.
Two particle azimuthal correlations are statistically the most precise
method of measuring anisotropic flow. The main drawback of this method
is its sensitivity to the non-flow correlations, which unlike real
flow, do not have geometrical origin. Non-flow contribution can be
estimated from two particle azimuthal correlations using $pp$ data.
Measurements of the non-flow contribution using the uQ method and
Scalar Product (SP) method are reported for $pp$ collisions at
$\sqrt{{s}_{NN}}=2.76$~TeV and $\sqrt{{s}_{NN}}=7$~TeV for the first
through fifth harmonics.
Femtoscopy of non-central heavy-ion collisions provides access to
information on the geometry of the effective pion-emitting source. In
particular, its shape can be studied by measuring femtoscopic radii as
a function of the emission angle relative to the collision plane of
symmetry. The first measurements of azimuthally differential
femtoscopy in Pb-Pb collisions at $\sqrt{{s}_{NN}}=2.76$~TeV are
reported and compared to results from RHIC experiments at lower
energies. Oscillations of the extracted radii versus the emission
angle are measured, and
$R_{side}$ and $R_{out}$
oscillations are found to be out of phase. The relative amplitude of
the $R_{side}$ oscillations decreases in more central collisions,
however always remains positive. This indicates that the source is
out-of-plane extended, similar to that observed at RHIC energies.
Results are compared to existing hydrodynamical and transport model
calculations.
Recommended Citation
Loggins, Vera Reneee, "Collective Flow And Azimuthally Differential Pion Femtoscopy With The Alice Experiment At The Lhc" (2014). Wayne State University Dissertations. 899.
https://digitalcommons.wayne.edu/oa_dissertations/899