Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userLinearized Boltzmann transport model for jet propagation in the quark-gluon plasma: Heavy quark evolution
127
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
A Linearized Boltzmann Transport (LBT) model coupled with hydrodynamical background is established to describe the evolution of jet shower partons and medium excitations in high energy heavy-ion collisions. We extend the LBT model to include both elastic and inelastic processes for light and heavy partons in the quark-gluon plasma. A hybrid model of fragmentation and coalescence is developed for the hadronization of heavy quarks. Within this framework, we investigate how heavy flavor observables depend on various ingredients, such as different energy loss and hadronization mechanisms, the momentum and temperature dependences of the transport coefficients, and the radial flow of the expanding fireball. Our model calculations show good descriptions of the $D$ meson suppression and elliptic flow observed at the LHC and RHIC. The prediction for the Pb-Pb collisions at $sqrt{s_mathrm{NN}}$=5.02~TeV is provided.
rate research
Read More
Several transport models have been employed in recent years to analyze heavy-flavor meson spectra in high-energy heavy-ion collisions. Heavy-quark transport coefficients extracted from these models with their default parameters vary, however, by up to a factor of 5 at high momenta. To investigate the origin of this large theoretical uncertainty, a systematic comparison of heavy-quark transport coefficients is carried out between various transport models. Within a common scheme devised for the nuclear modification factor of charm quarks in a brick medium of a quark-gluon plasma, the systematic uncertainty of the extracted drag coefficient among these models is shown to be reduced to a factor of 2, which can be viewed as the smallest intrinsic systematical error band achievable at present time. This indicates the importance of a realistic hydrodynamic evolution constrained by bulk hadron spectra and of heavy-quark hadronization for understanding the final heavy-flavor hadron spectra and extracting heavy-quark drag coefficient. The transverse transport coefficient is less constrained due to the influence of the underlying mechanism for heavy-quark medium interaction. Additional constraints on transport models such as energy loss fluctuation and transverse-momentum broadening can further reduce theoretical uncertainties in the extracted transport coefficients.
We study the evolution of the quark-gluon composition of the plasma created in ultra-Relativistic Heavy-Ion Collisions (uRHICs) employing a partonic transport theory that includes both elastic and inelastic collisions plus a mean fields dynamics associated to the widely used quasi-particle model. The latter, able to describe lattice QCD thermodynamics, implies a chemical equilibrium ratio between quarks and gluons strongly increasing as $Trightarrow T_c$, the phase transition temperature. Accordingly we see in realistic simulations of uRHICs a rapid evolution from a gluon dominated initial state to a quark dominated plasma close to $T_c$. The quark to gluon ratio can be modified by about a factor of $sim 20$ in the bulk of the system and appears to be large also in the high $p_T$ region. We discuss how this aspect, often overflown, can be important for a quantitative study of several key issues in the QGP physics: shear viscosity, jet quenching, quarkonia suppression. Furthermore a bulk plasma made by more than $80%$ of quarks plus antiquarks provides a theoretical basis for hadronization via quark coalescence.
In this paper we study the real-time evolution of heavy quarkonium in the quark-gluon plasma (QGP) on the basis of the open quantum systems approach. In particular, we shed light on how quantum dissipation affects the dynamics of the relative motion of the quarkonium state over time. To this end we present a novel non-equilibrium master equation for the relative motion of quarkonium in a medium, starting from Lindblad operators derived systematically from quantum field theory. In order to implement the corresponding dynamics, we deploy the well established quantum state diffusion method. In turn we reveal how the full quantum evolution can be cast in the form of a stochastic non-linear Schrodinger equation. This for the first time provides a direct link from quantum chromodynamics (QCD) to phenomenological models based on non-linear Schrodinger equations. Proof of principle simulations in one-dimension show that dissipative effects indeed allow the relative motion of the constituent quarks in a quarkonium at rest to thermalize. Dissipation turns out to be relevant already at early times well within the QGP lifetime in relativistic heavy ion collisions.
We present a new determination of $hat{q}$, the jet transport coefficient of the quark-gluon plasma. Using the JETSCAPE framework, we use Bayesian parameter estimation to constrain the dependence of $hat{q}$ on the jet energy, virtuality, and medium temperature from experimental measurements of inclusive hadron suppression in Au-Au collisions at RHIC and Pb-Pb collisions at the LHC. These results are based on a multi-stage theoretical approach to in-medium jet evolution with the MATTER and LBT jet quenching models. The functional dependence of $hat{q}$ on jet energy, virtuality, and medium temperature is based on a perturbative picture of in-medium scattering, with components reflecting the different regimes of applicability of MATTER and LBT. The correlation of experimental systematic uncertainties is accounted for in the parameter extraction. These results provide state-of-the-art constraints on $hat{q}$ and lay the groundwork to extract additional properties of the quark-gluon plasma from jet measurements in heavy-ion collisions.
The interaction of heavy flavor with the quark-gluon plasma (QGP) in relativistic heavy-ion collisions is studied using JETSCAPE, a publicly available software package containing a framework for Monte Carlo event generators. Multi-stage (and multi-model) evolution of heavy quarks within JETSCAPE provides a cohesive description of heavy flavor quenching inside the QGP. As the parton shower develops, a model becomes active as soon as its kinematic region of validity is reached. Two combinations of heavy-flavor energy-loss models are explored within a realistic QGP medium, using parameters which were tuned to describe {it light-flavor} partonic energy-loss.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
