English
Related papers

Related papers: With complex Langevin towards the QCD phase diagra…

200 papers

Monte Carlo studies of QCD at finite density suffer from the sign problem, which becomes easily uncontrollable as the chemical potential $\mu$ is increased even for a moderate lattice size. In this work we make an attempt to approach the…

High Energy Physics - Lattice · Physics 2018-12-06 Yuta Ito , Hideo Matsufuru , Jun Nishimura , Shinji Shimasaki , Asato Tsuchiya , Shoichiro Tsutsui

We summarise recent progress in simulating QCD at nonzero baryon density using complex Langevin dynamics. After a brief outline of the main idea, we discuss gauge cooling as a means to control the evolution. Subsequently we present a status…

High Energy Physics - Lattice · Physics 2014-12-03 Gert Aarts , Felipe Attanasio , Benjamin Jäger , Erhard Seiler , Denes Sexty , Ion-Olimpiu Stamatescu

The latest results of an ongoing project for the lattice simulation of QCD with a single quark flavor are presented. The Symanzik tree-level-improved Wilson action is adopted in the gauge sector and the (unimproved) Wilson action for the…

High Energy Physics - Lattice · Physics 2010-01-21 F. Farchioni , I. Montvay , G. Münster , E. E. Scholz , T. Sudmann , J. Wuilloud

We simulate one-flavor QCD with standard Wilson fermions at finite temperature by the rational hybrid Monte Carlo algorithm. In the heavy quark region when we decrease the quark mass there is an endpoint which terminates the first order…

High Energy Physics - Lattice · Physics 2008-11-26 Tetsuya Takaishi , Atsushi Nakamura

It is well known that investigating QCD at finite density by standard Monte Carlo methods is extremely difficult due to the sign problem. Some years ago, the complex Langevin method with gauge cooling was shown to work at high temperature,…

High Energy Physics - Lattice · Physics 2019-01-15 Keitaro Nagata , Jun Nishimura , Shinji Shimasaki

We present results of a lattice simulation of quantum chromodynamics with two degenerate flavors of dynamic Wilson fermions at $6/g^2=5.3$ at each of two dynamical fermion hopping parameters, $\kappa=0.1670$ and 0.1675, corresponding to…

High Energy Physics - Lattice · Physics 2009-10-22 K. M. Bitar

We explore the QCD phase diagram at finite density with four-flavor staggered fermions using the complex Langevin method, which is a promising approach to overcome the sign problem. In our previous work on an $8^3 \times 16$ lattice at…

High Energy Physics - Lattice · Physics 2019-12-03 Shoichiro Tsutsui , Yuta Ito , Hideo Matsufuru , Jun Nishimura , Shinji Shimasaki , Asato Tsuchiya

We demonstrate that the complex Langevin method (CLM) enables calculations in QCD at finite density in a parameter regime in which conventional methods, such as the density of states method and the Taylor expansion method, are not…

High Energy Physics - Lattice · Physics 2020-12-02 Yuta Ito , Hideo Matsufuru , Yusuke Namekawa , Jun Nishimura , Shinji Shimasaki , Asato Tsuchiya , Shoichiro Tsutsui

We study QCD at finite density and low temperature by using the complex Langevin method. We employ the gauge cooling to control the unitarity norm and introduce a deformation parameter in the Dirac operator to avoid the singular-drift…

High Energy Physics - Lattice · Physics 2018-04-18 Keitro Nagata , Jun Nishimura , Shinji Shimasaki

We apply the relative weights method to SU(3) gauge theory with staggered fermions of mass 695 MeV at a set of temperatures in the range $151 \le T \le 267$ MeV, to obtain an effective Polyakov line action at each temperature. We then apply…

High Energy Physics - Lattice · Physics 2018-06-13 Jeff Greensite , Roman Höllwieser

We present results for phase structure of lattice QCD with two degenerate flavors ($N_f=2$) of Wilson quarks at finite temperature $T$ and small baryon chemical potential $\mu_B$. Using the imaginary chemical potential for which the fermion…

High Energy Physics - Lattice · Physics 2008-11-26 Liang-Kai Wu , Xiang-Qian Luo , He-Sheng Chen

We present an update of our study of the phase diagram of two-flavour QCD at zero baryon density with dynamical $O(a)$ improved Wilson quarks. All simulations are done on lattices with a temporal extent of $N_t=16$ and spatial extent…

High Energy Physics - Lattice · Physics 2013-11-01 Bastian B. Brandt , Anthony Francis , Harvey B. Meyer , Owe Philipsen , Hartmut Wittig

We calculate connected and disconnected contributions to the flavour singlet scalar density amplitude of the nucleon in a full QCD lattice simulation with $n_f=2$ dynamical Wilson fermions at $\beta=5.6$ on a $16^3 \times 32$ lattice. We…

High Energy Physics - Lattice · Physics 2012-08-27 SESAM-Collaboration , : , S. Güsken , P. Ueberholz , J. Viehoff , N. Eicker , P. Lacock , T. Lippert , K. Schilling , A. Spitz , Th. Struckmann

Complex Langevin simulations provide an alternative to sample path integrals with complex weights and therefore are suited to determine the phase diagram of QCD from first principles. Adaptive step-size scaling and gauge cooling are used to…

High Energy Physics - Lattice · Physics 2015-11-02 Gert Aarts , Felipe Attanasio , Benjamin Jäger , Erhard Seiler , Dénes Sexty , Ion-Olimpiu Stamatescu

We study genuine finite density effects in QCD-like theories with three-dimensional Polyakov-loop effective theories for heavy quarks. These are derived from the full QCD-like theories by combined strong-coupling and hopping expansions. In…

High Energy Physics - Lattice · Physics 2016-02-16 Philipp Scior , Lorenz von Smekal

We use the linear sigma model with two flavors of quarks to study the phase diagram at finite temperature and baryon chemical potential as a function of the vacuum pion mass. Our calculations include thermal fluctuations of both the bosonic…

Nuclear Theory · Physics 2014-11-20 J. I. Kapusta , E. S. Bowman

We study the scaling properties of the finite temperature QCD phase transition, for light quark masses ranging from the heavy quark regime to their physical values. The lattice results are obtained in the fixed scale approach from…

High Energy Physics - Lattice · Physics 2021-11-03 A. Yu. Kotov , M. P. Lombardo , A. Trunin

Simulations of QCD with a finite chemical potential typically lead to a severe sign problem, prohibiting any standard Monte Carlo approach. Complex Langevin simulations provide an alternative to sample path integrals with oscillating weight…

High Energy Physics - Lattice · Physics 2014-11-12 Gert Aarts , Felipe Attanasio , Benjamin Jäger , Erhard Seiler , Denes Sexty , Ion-Olimpiu Stamatescu

We present results of an ongoing study of two flavour QCD with Wilson fermions at finite temperature. We have used tree level Symanzik improvement in both the gauge and fermion part of the action. The phase diagram was previously determined…

High Energy Physics - Lattice · Physics 2009-10-31 F. Karsch , E. Laermann , M. Oevers , P. Schmidt

We investigate high density state of SU(2) QCD by using Lattice QCD simulation with Wilson fermions. The ratio of fermion determinants is evaluated at each step of the Metropol is link update by Woodbury formula. At $\beta=0.7$, and $\kappa…

Nuclear Theory · Physics 2007-05-23 S. Muroya , A. Nakamura , C. Nonaka