Download or read book Nonequilibrium Probes of the Quark gluon Plasma written by Babak Salehi Kasmaei and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of high-energy nuclear physics is to understand the dynamics and properties of the various forms and phases of the strongly-interacting matter. Heavy-ion collision experiments are performed to deposit a large energy density in a very small volume of space and generate a form of extremely hot matter called the quark-gluon plasma (QGP). The behavior of the generated matter shows signatures of collectivity allowing phenomenological models based on statistical or fluid dynamical descriptions to be used successfully to analyze the outcomes the experiments. However, the very short lifetime and the extreme conditions of the QGP call for the construction of theoretical models based on the physics of nonequilibrium systems.Understanding the properties of QGP requires the study of collective excitations in the emergent many-body dynamics of the quarks and gluons as the fundamental objects in the theory of quantum chromodynamics. In this dissertation, the collective excitations of the nonequilibrium QGP are studied by calculating the quark and gluon self-energies within the hard loop effective theory. By extracting the solutions of the gluon dispersion relation in the complex plane, the presence of unstable modes in the momentum-anisotropic QGP is studied. The quark self-energy is also used to calculate the rate of photon emission from QGP in the subsequent studies performed as part of this dissertation. Electromagnetic probes (photons and dileptons) are considered among the best observables for extracting information about the early stages of evolution of the strongly interacting matter produced in heavy-ion collisions. In contrast to the hadrons, the emitted photons and leptons are not distorted by a strong coupling to the medium and they can escape the system with much larger mean free paths. Since the dilepton and photon emission rates from QGP are directly affected by the momentum distribution of the partonic degrees of freedom, their emission patterns can provide information about the nonequilibrium features of the system such as the momentum anisotropy of the distributions. In this dissertation, the effects of momentum anisotropy on the yields and elliptic flow coefficients of the dileptons and photons from QGP are investigated. The emission rates are calculated for distributions featuring ellipsoidal momentum anisotropies, and then the rates are convolved with the space-time evolution of the system using a relativistic hydrodynamical model. The effects of various parameters on the results are studied. In particular, the results are interpreted considering their connections to the extraction of early dynamics of QGP from future experimental data. Another important class of the probes of the nonequilibrium QGP is related to the dynamics of the heavy quarks in the system and their bound states. The properties of the heavy bound states, such as their decay rates, are affected by the hot and dense strongly interacting medium. Heavy quarks, due to their longer relaxation times, are also used to probe the transport properties of the QGP perturbed out of equilibrium. The potential for a bound state inside a hot medium may acquire an imaginary part. In this dissertation, the imaginary part of the heavy quark potential is calculated using classical-statistical simulations of the Yang-Mills theory on lattice. The connection of the results to the momentum diffusion of the heavy quarks is discussed. Lattice computation for the real-time dynamics of the non-Abelian theories allows for the nonperturbative analysis of the systems in and out of equilibrium.

Download or read book Collective Phenomena in the Non equilibrium Quark gluon Plasma written by Björn Peter Schenke and published by . This book was released on 2008 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Non equilibrium Hydrodynamics of the Quark gluon Plasma written by Nopoush Mohammad and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Relativistic heavy-ion collision experiments are currently the only controlled way to generate and study matter in the most extreme temperatures (T ~10e+12 K). At these temperatures matter undergoes a phase transition to an exotic phase of matter called the quark-gluon plasma (QGP). The QGP is an extremely hot and deconfined phase of matter where sub-nucleonic constituents (quarks and gluons) are asymptotically free. The QGP phase is important for different reasons. First of all, our universe existed in this phase up to approximately t ~10e-5 s after the Big Bang, before it cools down sufficiently to form any kind of quark bound states. In this regard, studying the QGP provides us with useful information about the dynamics and evolution of the early universe. Secondly, high-energy collisions serve as a microscope with a resolution on the order of 10e-15 m (several orders of magnitude more powerful than the best ever developed electron microscopes). With this fantastic probe, penetrating into the detailed structure of nucleons, and the discovery of new particles and fundamental phases are made possible. The dynamics of the QGP is based on quantum chromodynamics (which governs the interactions of quarks and gluons) and the associated force is "strong force". The strong collective behaviors observed experimentally inspired people to use dissipative fluid dynamics to model the dynamics of the medium. The QGP produced in heavy-ion collisions, experiences strong longitudinal expansion at early times which leads to a large momentum-space anisotropy in the local rest frame distribution function. The rapid longitudinal expansion casts doubt on the application of standard viscous hydrodynamics (vHydro) models, which lead to unphysical predictions such as negative pressure, negative one-particle distribution function, and so on. Anisotropic hydrodynamics (aHydro) takes into account the strong momentum-space anisotropy in the leading order distribution function in a consistent and systematic way. My dissertation is about the formulation and application of anisotropic hydrodynamics as a successful non-equilibrium hydrodynamics model for studying the QGP. For this purpose, I introduce the basic conformal anisotropic hydrodynamics formalism and then explain the ways we included realistic features (bulk degree of freedom, quasiparticle implementation of realistic equation of state, more realistic collisional kernel), to make it a suitable hydrodynamics model for studying the QGP generated in heavy-ion collisions. For verification of our model we have compared the evolution of model parameters predicted by aHydro and vHydro, with exact analytical solution of the Boltzmann equation. For this purpose, we have studied the evolution of the system under conformal Gubser flow using the aHydro model. By transforming to de Sitter spacetime (a non-trivial curved coordinate system) we simplified the dynamics to 0+1d spacetime. Comparisons with exact solutions show that aHydro better reproduces the exact solutions than the best available vHydro models. However, the system is not conformal and the aHydro needed to be improved to include a realistic prescription for the equation of state which takes care of non-ideal effect in the dynamics. In the framework of finite temperature eld theory the equation of state is provided by numerical calculation of QCD partition function using lattice QCD (LQCD), whereas, devising an equation of state for aHydro model is challenging because therein we deal with anisotropic pressures. In the next step of my research, we have designed a novel method for implementing the realistic equation of state (provided by lattice QCD) in the aHydro formalism. This model, called the quasiparticle aHydro model, integrates the non-conformal effects in the aHydro model. The non-conformal effects are due to strong interactions of plasma constituents which leads to temperature-dependence of the particles' effective mass in the system. Based on the quasiparticle picture, we have developed the quasiparticle aHydro (aHydroQP) model which has all necessary components for studying the phenomenology of the QGP created in heavy-ion collisions. We have then compared the phenomenological predictions of the aHydroQP model with experimental observations. Comparisons illustrate a high level of consistency between our model and the experimental data. The last two chapters are about two applications of the aHydro model to field-theoretical measurables in the QGP. In these chapters, we have calculated the quark self-energy in an anisotropic QGP. The quark self-energy is important because it encodes the way quarks gain interactional mass while in the hot QGP. I also have presented the calculation of gluon self-energy in hard loop approximation in an anisotropic QGP.The gluon self-energy is important since it is related to heavy-quark potential and heavy quarkonium suppression. Heavy quarkonia bound states, besides theoretical importance, serve as a thermometer for the QGP.

Download or read book Momentum Broadening and Collinear Radiation in a Non equilibrium Quark gluon Plasma written by Sigtryggur Hauksson and published by . This book was released on 2022 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Heavy-ion collisions produce high-temperature strongly interacting matter known as the quark-gluon plasma. The plasma is out of thermal equilibrium at all stages of its evolution and thus provides a window into transport coefficients and hydrodynamization of non-equilibrium quantum chromodynamics (QCD): the theory of the strong force. Jets and photons are two experimental probes that are particularly sensitive to the evolution of the plasma, including its non-equilibrium properties. In order to use these probes to study non-equilibrium QCD, a thorough understanding of the physics of jets and photons in a non-equilibrium plasma is needed. This includes transverse momentum broadening of jet partons, as well as the collinear bremsstrahlung of photons and gluons. In this thesis, we evaluate the rate of transverse momentum broadening of a parton in a non-equilibrium plasma. This is done by calculating the occupation density of soft gluons radiated by medium particles which are assumed to be anisotropically distributed in momentum space. Our results show that momentum broadening is reduced relative to a plasma in equilibrium because of increased screening. We furthermore establish that spurious divergences in the rate of momentum broadening are due to plasma instabilities and are cured when time evolution of the plasma is taken into account. To do this we evaluate analytically the time evolution of two-point gluon correlators in an unstable plasma. Finally, we analyze collinear bremsstrahlung of photons and gluons in a non-equilibrium plasma. Our calculation includes the Landau-Pomeranchuk-Migdal effect. We develop numerical methods to calculate the bremsstrahlung rate in an anisotropic plasma and show that the rate of photon production is reduced compared with thermal equilibrium, especially at higher photon momenta"--

Download or read book Nonequilibrium Dynamics of the Quark gluon Plasma in Heavy Ion Collisions written by and published by . This book was released on 1997 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). We have developed field theory and numerical methods for the general problem of quantum back reaction on classical fields, with applications to a wide variety of physical systems. Our main focus was on particle production processes in the time evolution of the quark-gluon plasma following an ultrarelativistic heavy-ion collision. In particular, we studied in some detail the evolution of a disoriented chiral condensate (DCC) produced in the chiral phase transition of nuclear matter in heavy-ion collision experiments. We have also studied dissipation and decoherence as a result of particle production in time-varying mean fields. Numerical codes previously developed for particle production in strong electric fields in quantum electrodynamics (QED) have been modified for the quantum chromodynamics (QCD) problem. We have made specific predictions for energy-momentum flow and pion production in the central rapidity region of experiments to be performed at the Relativistic Heavy-Ion Collider (RHIC).

Download or read book Non equilibrium Hydrodynamics of the Quark Gluon Plasma from Theory to Phenomenology written by Dekrayat K. Almaalol and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The quark-gluon plasma (QGP) is a deconfined phase of strongly interacting matter which can be described by the theory of quantum chromodynamics (QCD). The QGP filled the entire universe in the early moments after the big bang and is believed to exist in the present time in the core of massive neutron stars. Understanding the physical properties of QGP and its non-equilibrium dynamics requires solving the full non-perturbative QCD equations of motion, which is an unsolved problem at this time. Ultra-relativistic heavy ion collisions (URHICs) can be used to reproduce the extreme conditions of the early universe and create a short-lived QGP in the laboratory; in what is called the ``little'' bang. The highly momentum-anisotropic far-from-equilibrium initial state created in these experiments evolves dynamically in three main stages: pre-equilibrium ([tau] 0.5 fm/c), thermalization/hydrodynamization ([tau] 0.5-2 fm/c), and finally freeze-out/hadronization ([tau]> 10 fm/c), where 1fm/c = 3x10^(-24) s. Each of these stages span a different regime of physics, with different relevant degrees of freedom and, therefore, are described by different theoretical models, such as QCD kinetic theory, dissipative hydrodynamics, and hadronic kinetic theory. This dissertation considers the impact of all three of these stages on our understanding of the QGP generated in URHICs, with the focus on better understanding the non-equilibrium dynamics of the QGP, its path to equilibrium and the effect such non-equilibrium dynamics have on our ability to extract fundamental information about the QGP. This dissertation also provides theoretical insights into how to improve URHIC simulations by examining the impact of non-equilibrium corrections present during different stages of QGP evolution.

Download or read book Hard Probes of the Quark gluon Plasma written by Simon Caron Huot and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Consistent Description of Kinetics and Hydrodynamics of Quark gluon Plasma on the Basis of Nonequilibrium Thermofield Dynamics written by M. V. Tokarchuk and published by . This book was released on 1993 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Probes of the Quark Gluon Plasma as It Might Be Produced in Ultrarelativistic Nuclear Collisions written by and published by . This book was released on 1984 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dilepton Production from a Non equilibrium Quark gluon Plasma in Ultrarelativistic Nucleus nucleus Collisions written by M. Asakawa and published by . This book was released on 1990 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Physics of the Quark gluon Plasma written by Sourav Sarkar and published by . This book was released on 2010 with total page 369 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Physics of the Quark Gluon Plasma written by Berndt Müller and published by Springer. This book was released on 1985-03 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Globally Polarized Quark gluon Plasma in Non central A ACollisions written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Produced partons have large local relative orbital angular momentum along the direction opposite to the reaction plane in the early stage of non-central heavy-ion collisions. Parton scattering is shown to polarize quarks along the same direction due to spin-orbital coupling. Such global quark polarization will lead to many observable consequences, such as left-right asymmetry of hadron spectra, global transverse polarization of thermal photons, dileptons and hadrons. Hadrons from the decay of polarized resonances will have azimuthal asymmetry similar to the elliptic flow. Global hyperon polarization is predicted with indifferent hadronization scenarios and can be easily tested.

Download or read book Very High Energy Probes of the Quark gluon Plasma written by and published by . This book was released on 1984 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Very High Energy Probes Of The Quark Gluon Plasma written by and published by . This book was released on 1984 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nonequilibrium Quantum Field Theory written by Esteban A. Calzetta and published by Cambridge University Press. This book was released on 2023-01-31 with total page 553 pages. Available in PDF, EPUB and Kindle. Book excerpt: This 2008 book, reissued as OA, captures the essence of nonequilibrium quantum field theory, graduate students and researchers.

Download or read book The Physics of the Quark gluon Plasma written by Jorge Dias Deus and published by World Scientific Publishing Company. This book was released on 1988 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: