An estimate for the thermal photon rate from lattice QCD

We estimate the production rate of photons by the quark-gluon plasma in lattice QCD. We propose a new correlation function which provides better control over the systematic uncertainty in estimating the photon production rate at photon momenta in the range πT/2 to 2πT. The relevant Euclidean vector current correlation functions are computed with Nf = 2 Wilson clover fermions in the chirally-symmetric phase. In order to estimate the photon rate, an ill-posed problem for the vector-channel spectral function must be regularized. We use both a direct model for the spectral function and a modelindependent estimate from the Backus-Gilbert method to give an estimate for the photon rate.

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Insight into Thermal Modifications of Quarkonia From a Comparison of Continuum-Extrapolated Lattice Results to Perturbative QCD

Proceedings ◽

10.3390/proceedings2019010045 ◽

2019 ◽

Vol 10 (1) ◽

pp. 45 ◽

Cited By ~ 1

Author(s):

Anna-Lena Kruse ◽

H.-T. Ding ◽

O. Kaczmarek ◽

H. Ohno ◽

H. Sandmeyer

Keyword(s):

Heavy Quark ◽

Spectral Function ◽

Bound States ◽

Low Frequency ◽

Vector Channel ◽

Systematic Uncertainties ◽

Integration Kernel ◽

Frequency Regime ◽

Ill Posed ◽

Insight Into

In this work, we strive to gain insight into thermal modifications of charmonium and bottomonium bound states as well as the heavy quark diffusion coefficient. The desired information is contained in the spectral function which can not be calculated on the lattice directly. Instead, the correlator given by an integration over the spectral function times an integration kernel is obtained. Extracting the spectral function is an ill-posed inversion problem and various different solutions have been proposed. We focus on a comparison to a spectral function obtained from combining perturbative and pNRQCD calculations. In order to get precise results, continuum extrapolated correlators originating from large and fine lattices are used. We first analyze the pseudoscalar channel since the absence of a transport peak simplifies the analysis. The knowledge gained from this is then used to extend the analysis to the vector channel, where information on heavy quark transport is encoded in the low frequency regime of the spectral function. The comparison shows a qualitatively good agreement between perturbative and lattice correlators. Quantitative differences can be explained by systematic uncertainties.

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Thermal dilepton rate and electrical conductivity: An analysis of vector current correlation functions in quenched lattice QCD

Physical Review D ◽

10.1103/physrevd.83.034504 ◽

2011 ◽

Vol 83 (3) ◽

Cited By ~ 160

Author(s):

H.-T. Ding ◽

A. Francis ◽

O. Kaczmarek ◽

F. Karsch ◽

E. Laermann ◽

...

Keyword(s):

Electrical Conductivity ◽

Lattice Qcd ◽

Correlation Functions ◽

Vector Current ◽

Current Correlation

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Quark Cluster Expansion Model for Interpreting Finite-T Lattice QCD Thermodynamics

Symmetry ◽

10.3390/sym13030514 ◽

2021 ◽

Vol 13 (3) ◽

pp. 514

Author(s):

David Blaschke ◽

Kirill A. Devyatyarov ◽

Olaf Kaczmarek

Keyword(s):

Lattice Qcd ◽

Cluster Expansion ◽

Quark Gluon Plasma ◽

Degrees Of Freedom ◽

Gluon Plasma ◽

Polyakov Loop ◽

Unified Approach ◽

Narrow Temperature Interval ◽

Levinson Theorem ◽

Expansion Model

In this work, we present a unified approach to the thermodynamics of hadron–quark–gluon matter at finite temperatures on the basis of a quark cluster expansion in the form of a generalized Beth–Uhlenbeck approach with a generic ansatz for the hadronic phase shifts that fulfills the Levinson theorem. The change in the composition of the system from a hadron resonance gas to a quark–gluon plasma takes place in the narrow temperature interval of 150–190 MeV, where the Mott dissociation of hadrons is triggered by the dropping quark mass as a result of the restoration of chiral symmetry. The deconfinement of quark and gluon degrees of freedom is regulated by the Polyakov loop variable that signals the breaking of the Z(3) center symmetry of the color SU(3) group of QCD. We suggest a Polyakov-loop quark–gluon plasma model with O(αs) virial correction and solve the stationarity condition of the thermodynamic potential (gap equation) for the Polyakov loop. The resulting pressure is in excellent agreement with lattice QCD simulations up to high temperatures.

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Transport Coefficient of Gluon Plasma from Lattice QCD

10.22323/1.020.0186 ◽

2005 ◽

Author(s):

Sunao Sakai ◽

Atsushi Nakamura

Keyword(s):

Lattice Qcd ◽

Transport Coefficient ◽

Gluon Plasma

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Pion valence quark distribution from current-current correlation in lattice QCD

Physical Review D ◽

10.1103/physrevd.102.054508 ◽

2020 ◽

Vol 102 (5) ◽

Cited By ~ 5

Author(s):

Raza Sabbir Sufian ◽

Colin Egerer ◽

Joseph Karpie ◽

Robert G. Edwards ◽

Bálint Joó ◽

...

Keyword(s):

Lattice Qcd ◽

Valence Quark ◽

Quark Distribution ◽

Current Correlation

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Gluon-propagator functional form in the Landau gauge in SU(3) lattice QCD: Yukawa-type gluon propagator and anomalous gluon spectral function

Physical Review D ◽

10.1103/physrevd.80.114505 ◽

2009 ◽

Vol 80 (11) ◽

Cited By ~ 22

Author(s):

Takumi Iritani ◽

Hideo Suganuma ◽

Hideaki Iida

Keyword(s):

Lattice Qcd ◽

Spectral Function ◽

Functional Form ◽

Gluon Propagator ◽

Landau Gauge

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Dilepton production in thermal-dependent baryonic quark–gluon plasma

Canadian Journal of Physics ◽

10.1139/cjp-2012-0554 ◽

2014 ◽

Vol 92 (1) ◽

pp. 31-35 ◽

Cited By ~ 3

Author(s):

S. Somorendro Singh ◽

Yogesh Kumar

Keyword(s):

Production Rate ◽

Quark Gluon Plasma ◽

Chemical Potential ◽

Gluon Plasma ◽

Mass Region ◽

Dilepton Production ◽

Production Rates ◽

Baryonic Chemical Potential ◽

Low Mass ◽

Quark Mass Dependence

We evolute a fireball of quark–gluon plasma (QGP) at thermal-dependent chemical potential (TDCP) through a statistical model in the pionic medium. The evolution of the fireball is explained through the free energy created in the pionic medium. We study the dilepton production at TDCP from such a fireball of QGP and hadronic phase. In this model, we take a finite quark mass dependence on temperature and parametrization factor. The temperature and factor enhance in the growth of the droplet formation of quarks and gluons as well as in the dilepton production rates. The production rate shows dilepton spectrum in the low mass region of the lepton pair as 0–1.2 GeV and in the intermediate mass region of 1.0–4.0 GeV. The rate of production is observed to be a strong increasing function of the TDCP for quark and antiquark annihilation. We compare the result of dilepton production at this TDCP with the production rate of the recent dilepton productions at zero and finite baryonic chemical potential and found the result far ahead in the production rates of dilepton at TDCP.

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A Theory for Predicting the Turbulent-Spot Production Rate

Volume 1: Turbomachinery ◽

10.1115/98-gt-256 ◽

1998 ◽

Author(s):

R. E. Mayle

Keyword(s):

Boundary Layer ◽

Production Rate ◽

Free Stream ◽

Length Scale ◽

Bypass Transition ◽

Turbulence Level ◽

Turbulent Spot ◽

Boundary Layer Flows ◽

Free Stream Turbulence ◽

New Correlation

A theory is presented for predicting the production rate of turbulent spots. The theory, based on that by Mayle-Schulz for bypass transition, leads to a new correlation for the spot production rate in boundary layer flows with a zero pressure gradient. The correlation, which agrees reasonably well with data, clearly shows the effects of both free-stream turbulence level and length scale. In addition, the theory provides an estimate for the lowest level of free-stream turbulence causing bypass transition.

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