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We extend the density-of-states approach to gauge systems (LLR method) to QCD at finite temperature and density with heavy quarks. The approach features an exponential error suppression and yields the Polyakov loop probability distribution…

High Energy Physics - Lattice · Physics 2013-11-18 Kurt Langfeld , Jan M. Pawlowski

We compute the two-loop fermion self-energy in massless reduced quantum electrodynamics for an arbitrary gauge using the method of integration by parts. Focusing on the limit where the photon field is four-dimensional, our formula involves…

High Energy Physics - Phenomenology · Physics 2014-03-31 A. V. Kotikov , S. Teber

We calculate the leading mass-suppressed two-loop contribution, proportional to alpha_s^3/(m_q r^2), to the potential of a heavy quark-antiquark system. This contribution originates in the nonabelian nature of quantum chromodynamics (QCD)…

High Energy Physics - Phenomenology · Physics 2011-07-19 Bernd A. Kniehl , Alexander A. Penin , Vladimir A. Smirnov , Matthias Steinhauser

We apply optimized perturbation theory to the quark-meson model at finite temperature T and quark chemical potential mu. The effective potential is calculated to one loop both in the chiral limit and at the physical point and used to study…

High Energy Physics - Phenomenology · Physics 2011-02-15 Jens O. Andersen , Rashid Khan , Lars T. Kyllingstad

The Cornell potential with the best fitted parameters $\alpha_{s}$ and $\kappa$ are modified by adding terms derived from non-perturbative QCD, which are characterized by a series of non-vanishing vacuum condensates of quarks and gluons. In…

High Energy Physics - Phenomenology · Physics 2008-11-26 Y. B. Ding , X. -H. Guo , X. Q. Li , P. N. Shen

The QCD one-loop renormalization is restudied in a mass-dependent subtraction scheme in which the quark mass is not set to vanish and the renormalization point is chosen to be an arbitrary timelike momentum. The correctness of the…

High Energy Physics - Theory · Physics 2007-05-23 Jun-Chen Su , Lian-You Shan , Ying-Hui Cao

QCD at fixed baryon number can be formulated in terms of transfer matrices explicitly defined in the canonical sectors. In the heavy-dense limit, the fermionic contributions to the canonical partition functions in terms of Polyakov loops…

High Energy Physics - Lattice · Physics 2021-10-29 Patrick Bühlmann , Urs Wenger

In recent years the perturbative expansion of the pressure of massless QCD has been driven to order g^6ln(g) at high temperatures and finite chemical potentials, which has required calculations up to three-loop order in the full theory and…

High Energy Physics - Phenomenology · Physics 2009-11-10 A. Vuorinen

We have investigated the spectra of light-heavy quarkonia with the use of a quantum-chromodynamic potential model which is similar to that used earlier for the heavy quarkonia. An essential feature of our treatment is the inclusion of the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Suraj N. Gupta , James M. Johnson

Based on the observation that the heavy quark-antiquark potential value at infinity corresponds to twice the D meson mass, we constrain the asymptotic value of the heavy quark potential in a hot medium through a QCD sum rule calculation of…

High Energy Physics - Phenomenology · Physics 2020-06-30 Philipp Gubler , Taesoo Song , Su Houng Lee

The first-principle approach to the dense state of QCD matter, i.e. the lattice-QCD simulation at finite baryon density, is not under theoretical control for the moment. The effective model study based on QCD symmetries is a practical…

High Energy Physics - Phenomenology · Physics 2015-05-19 Kenji Fukushima

We compare SU(2) Polyakov loop models with different effective actions with data from full two-color QCD simulations around and above the critical temperature. We then apply the effective theories at finite temperature and density to…

High Energy Physics - Lattice · Physics 2014-12-23 Philipp Scior , David Scheffler , Dominik Smith , Lorenz von Smekal

It is argued that it is valid to use QCD sum rules to determine the scalar and pseudoscalar two-point functions at zero momentum, which in turn determine the ratio of the strange to non-strange quark condensates $R_{su} = \frac{<\bar{s}…

High Energy Physics - Phenomenology · Physics 2009-01-06 C. A. Dominguez , N. F. Nasrallah , K. Schilcher

We give a recurrence relation for two-loop integrals encountered in the effective field theory of an infinitely heavy quark, Q, interacting with gluons and Nl massless quarks, q, from which we obtain exact two-loop results, in any dimension…

High Energy Physics - Phenomenology · Physics 2010-11-01 D. J. Broadhurst , A. G. Grozin

We discuss the thermodynamics of two-colour QCD with four flavours of staggered quarks on 8^3x4 and 16^3x4 lattices. In our simulations we use the Naik action for the fermions and a (1,2) tree-level improved gauge action. We analyze the…

High Energy Physics - Lattice · Physics 2016-09-01 O. Kaczmarek , F. Karsch , E. Laermann

A comprehensive determination of the quark mass dependence in the dispersion relations of thermal excitations of gluons and quarks in non-Abelian gauge theory (QCD) is presented for the one-loop approximation in Feynman gauge. Larger values…

High Energy Physics - Phenomenology · Physics 2014-11-18 D. Seipt , M. Bluhm , B. Kampfer

We give an outline of a recent proof that the low-energy effective gauge theory exhibiting quark confinement due to magnetic monopole condensation can be derived from QCD without any specific assumption. We emphasize that the low-energy…

High Energy Physics - Theory · Physics 2008-11-26 Kei-Ichi Kondo

We calculate the two-loop QCD corrections to $gg \to ZZ$ involving a closed top-quark loop. We present a new method to systematically construct linear combinations of Feynman integrals with a convergent parametric representation, where we…

High Energy Physics - Phenomenology · Physics 2021-06-16 Bakul Agarwal , Stephen P. Jones , Andreas von Manteuffel

A method of computing two-loop fermionic contributions to the width of a heavy quark is described. An analytical formula for this effect in the limit of mass of the quark much larger than the decay products is obtained for the first time.…

High Energy Physics - Phenomenology · Physics 2011-03-02 Andrzej Czarnecki

We evaluate the second and fourth order quark number susceptibilities in hot QCD using two variations of resummed perturbation theory. On one hand, we carry out a one-loop calculation within hard-thermal-loop perturbation theory, and on the…

High Energy Physics - Phenomenology · Physics 2013-04-10 Jens O. Andersen , Sylvain Mogliacci , Nan Su , Aleksi Vuorinen