Abstract: Anisotropic flow in high energy heavy-ion collisions is taken as a key evidence for the formation of QGP for brief seconds right after the collisions. Hydrodynamic models including QGP formation are accurate at predicting the azimuthal anisotropy of the produced particles at low transverse momenta. At high momenta however, hydrodynamic models predict no azimuthal anisotropy for particles of different masses and quark-flavors; the logic being that because of their high momenta, the particles pass through the media without having any time to have any reactivity. This is contrary to results from experiments where measurements of particles of different quark flavors show non-zero elliptic flow. To study this deviation, we run PYTHIA simulation of proton-proton collisions at center- of-mass energies equivalent to those at RHIC and LHC; 200 GeV and 13 TeV. Since in PYTHIA simulations no QGP if formed, and there is no final-state interaction, results in our simulation would act as probes to be compared to the results of elliptic flow from real experiments. Our results showed non-zero results for the elliptic flow of pions, heavy mesons and direct photons. Those results are evident of the possible bias in the way the reaction plane is calculated, since all the other factors are controlled for in the PYTHIA simulations. To make up for this inherent bias, the results from PYTHIA should be subtracted from the results of elliptic flow in real experiments, to end up with unbiased results for elliptic flow from the different colliders.

At the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL), Long Island, NY, the main goal of research into heavy-ion collisions has been to understand Quantum Chromo Dynamics (QCD) in conditions of extreme temperature and energy density. At ordinary temperatures, the quarks and gluons are confined within particles like protons and neutrons, but at very high temperatures and densities, a new deconfined phase of quarks and gluons is created. This new phase is known as Quark Gluon Plasma (QGP).Quarks with the quantum numbers "charm" and "bottom" are relatively massive and are produced only rarely, and this category is called heavy flavor. Heavy-flavor measurements deepen our understanding of the properties and nature of the excited QGP state. Heavy-flavor particles are unique probes for studies of the hot and dense QGP medium created in high-energy collisions, as they are produced early in the evolution of the collision.STAR (Solenoidal Tracker At RHIC) is now the last operational detector at the RHIC facility, and was constructed and is operated by a large international collaboration. The STAR collaboration is composed of 68 institutions from 14 countries, with a total of 743 collaborators. In 2014, STAR employed a new silicon pixel technology detector named the Heavy Flavor Tracker (HFT). The HFT has separate layers of silicon to guide tracks reconstructed in the main tracking detector of STAR (the Time Projection Chamber) down to a spatial resolution of around 30 [mu]m in the region near the center of STAR where the collisions occur, which allows particles with very short lifetimes (notably heavy flavor particles) to be identified.In this dissertation, I use the HFT to measure particles with the charm quantum number. This work also involves using a pair of calorimeter detectors at a polar angle of zero degrees to estimate the azimuthal angle of the reaction plane in each collision. About 2.2 billion collisions are in the dataset being studied. These measurements allow the azimuthal anisotropy (flow) of charmed particles to be studied. The results are compared to similar studies involving light quarks and the predictions of several theoretical models. My results show a surprisingly large first Fourier harmonic in the anisotropy for particles with charm compared with particles with lighter flavors (strange, up, down). Specifically, the signal for charm is about 30 times larger, and no model comes anywhere close to predicting this pattern.

This is an updated version of the book published in 1985. QCD-motivated, it gives a detailed description of hadron structure and soft interactions in the additive quark model, where hadrons are regarded as composite systems of dressed quarks. In the past decade it has become clear that nonperturbative QCD, responsible for soft hadronic processes, may differ rather drastically from perturbative QCD. The understanding of nonperturbative QCD requires a detailed investigation of the experiments and the theoretical approaches. Bearing this in mind, the book has been rewritten paying special attention to the interplay of soft hadronic collisions and the quark model. It is at the crossroads of these domains that peculiar features of strong QCD reveal themselves. The book discusses constituent quarks, diquarks, the massive effective gluons and the problem of scalar isoscalar mesons. The quark-gluonium classification of meson states is also given. Experimentally observed properties of hadrons are presented together with the corresponding theoretical interpretation in the framework of the composite hadron structure. The text includes a large theoretical part, which shows how to treat composite systems (including relativistic ones) with a technique based on spectral integration. This technique provides the possibility of handling hadrons as weakly bound systems of quarks and, at the same time, takes into account confinement. Attention is focused on the composite structure revealing itself in high energy hadron collisions. Fields of applicability of the additive quark model are discussed, as is colour screening in hadronic collisions at high and superhigh energies. Along with a detailed presentation of hadronOCohadron collisions, a description of hadronOConucleus collisions is given. Sample Chapter(s). Chapter 1: Introduction (1,047 KB). Contents: High Energy Hadron Interactions; Composite Systems; High Energy Interactions of Composite Systems; Hadron Zoology and Static Features of Hadrons; Binary Processes in the Quark Model; Multiparticle Production in the Quark Model: Hadron Collisions at Moderately High Energies; HadronOCoNucleus Collisions. Readership: Graduate students and researchers in particle and nuclear physics."

Heavy flavor quarks are produced early in heavy ion collisions and will experience the full evolution of the Quark Gluon Plasma (QGP). Measurements at forward rapidity may be influenced as much, or more, by the cold nuclear matter effects as by the hot nuclear matter effects associated with a QGP. As the medium evolves, the initial spatial anisotropy of participants is converted to an azimuthal anisotropy in the momentum space of outgoing particles. Therefore, the momentum spectra modification and anisotropy parameters provide useful information about the heavy quark interaction with the bulk medium. Asymmetric heavy ion collisions, such as Cu+Au, provide a unique geometry with which to study the dynamics of the heavy quarks, relative to that in symmetric collisions. In particular, asymmetries in the yields between the Cu-going and Au-going directions may help unentangle the so-called cold nuclear matter effects from the hot nuclear matter effects indicative of a QGP. In addition, the parameters v2 and v3 in asymmetric collisions may be modified relative to the symmetric collisions due to the unique geometry provided in mid-central Cu+Au collisions. This dissertation presents the measurement of the yield and azimuthal anisotropy of single muons originating from heavy flavor decays in [square root of]SNN [center-of-mass energy per nucleon] = 200 GeV Cu+Au collisions.

The azimuthal anisotropy of charged particles in PbPb collisions at nucleon-nucleon center-of-mass energy of 2.76 TeV is measured with the CMS detector at the LHC over an extended transverse momentum (pt) range up to approximately 60 GeV. The data cover both the low-pt region associated with hydrodynamic flow phenomena and the high-pt region where the anisotropies may reflect the path-length dependence of parton energy loss in the created medium. The anisotropy parameter (v2) of the particles is extracted by correlating charged tracks with respect to the event-plane reconstructed by using the energy deposited in forward-angle calorimeters. For the six bins of collision centrality studied, spanning the range of 0-60% most-central events, the observed v2 values are found to first increase with pt, reaching a maximum around pt = 3 GeV, and then to gradually decrease to almost zero, with the decline persisting up to at least pt = 40 GeV over the full centrality range measured.