Physical Sciences and Mathematics Commons^™

New Aspects Of Scattering Amplitudes, Higher-K Amplitudes, And Holographic Quark Gluon Plasmas, Bruno Giménez Umbert

Electronic Thesis and Dissertation Repository

We present new results on different aspects of quantum field theory, which are divided into three main parts. In part I, we find and prove a new behavior of massless tree-level scattering amplitudes, including the biadjoint scalar theory, the U(N) non-linear sigma model, and the special Galileon, within specific subspaces of the kinematic space. We also derive new formulas for the double-ordered biadjoint scalar and $\phi^p$ amplitudes, which can be obtained as integrals over the positive tropical Grassmannian and under limiting procedures on the kinematic invariants. This reveals surprising connections with cubic amplitudes. We also present alternative versions of the …

Jet Geometry Engineering Via Di-Jet Imbalance Measurements At Rhic In Star, Nicholas Elsey

Wayne State University Dissertations

Ultra-relativistic heavy ion collisions produced at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC) produce a new state of matter of deconfined quarks and gluons (partons) called the quark-gluon plasma (QGP). This plasma of deconfined but strongly coupled partons is believed to have been the primary state of matter in the universe up to a few milliseconds after the Big Bang. High energy partons produced in hard scatterings early in the collision can be used to probe the entire lifetime of the QGP. These partons propagate through and interact with the QGP before fragmenting into collimated …

Production Of Electrons From Heavy Flavor Decays In Proton-Lead Collisions Measured With Alice At The Lhc, Rebecca Michelle Scott

Doctoral Dissertations

This dissertation presents a measurement of the yield and cross section of electrons from heavy flavor decays at central rapidity in proton-lead collisions measured by the ALICE (A Large Ion Collider Experiment) detector at the Large Hadron Collider. This analysis extends the transverse momentum reach of an earlier measurement in ALICE and the comparison is shown. The cross section of single electrons in proton-lead collisions is compared to the value expected in the absence of nuclear modification from proton-proton collisions. The cross section is well described by the perturbative Quantum Chromodynamics and no statistically significant alteration due to hot nuclear …

Collective Flow And Azimuthally Differential Pion Femtoscopy With The Alice Experiment At The Lhc, Vera Reneee Loggins

Wayne State University Dissertations

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 …

Centrality Dependence Of Two-Particle Number And Transverse Momentum Correlations In 200 Gev Au+Au Collisions At Rhic, Laurence Henry Tarini

Wayne State University Dissertations

We present plots of the pattern of particle formation in $sqrt{s_{NN}}=200$ GeV Au+Au heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC) using three different two-particle correlation measurements of number and transverse momentum as a function of relative azimuth, pseudorapidity and centrality. All three observables show the onset of a ``ridge" feature of enhanced correlations in pseudorapidity with increasing centrality. The plots of real data are compared to plots of simulations using RQMD data and data from a simple ``cluster'' model. The intent of the analysis is to analyze the role of radial flow in the onset of the …

Developing A B-Jet Tagging Algorithm For Alice: Lessons From Cdf, Paul Chester-John Carlson

Physics

This paper compares the detectors and algorithms developed and used at both A Large Ion Collider Experiment (ALICE) and the Collider Detector at Fermilab (CDF). We found that the detectors share many similarities in data collection and analysis methods and that by adapting algorithms that have been tested and used at CDF, ALICE could augment its existing algorithms. The algorithms formed from this adaptation will help ALICE isolate b-jets quickly and explore the quark-gluon plasma, ultimately expanding our understanding of the strong nuclear force and its role in the evolution of our universe.