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Related papers: Systematic approximation for QCD at non-zero densi…

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Convergence properties of Taylor expansions of observables, which are also used in lattice QCD calculations at non-zero chemical potential, are analyzed in an effective N_f = 2+1 flavor Polyakov-quark-meson model. A recently developed…

High Energy Physics - Phenomenology · Physics 2011-03-29 Frithjof Karsch , Bernd-Jochen Schaefer , Mathias Wagner , Jochen Wambach

We present a lattice investigation, partially including the effects of dynamical quarks, of the heavy-light mesons using NRQCD for the heavy quark and the Wilson action for the light quark. We performed an extensive calculation of the…

High Energy Physics - Lattice · Physics 2010-01-18 S. Collins , U. M. Heller , J. Sloan , J. Shigemitsu , A. Ali Khan , C. Davies

We discuss the equation of state for QCD at non-zero temperature and density. We present results of a simulation for QCD with 2 flavors of p4-improved staggered fermions. Derivatives of $\ln {\cal Z}$ with respect to quark chemical…

High Energy Physics - Lattice · Physics 2009-11-10 S. Ejiri , C. R. Allton , S. J. Hands , O. Kaczmarek , F. Karsch , E. Laermann , C. Schmidt

We present the results of a precision computation of B_K with Wilson fermions. Simulations are performed at different lattice spacings, enabling continuum limit extrapolations. Two different twisted mass QCD (tmQCD) regularisations are…

High Energy Physics - Lattice · Physics 2007-05-23 P. Dimopoulos , J. Heitger , C. Pena , S. Sint , A. Vladikas

We use complex Langevin simulations to explore the QCD phase diagram over a large range of chemical potentials and temperatures. For our simulations, we use two flavours of dynamical Wilson fermions with a pion mass of approximately…

High Energy Physics - Lattice · Physics 2021-11-04 Felipe Attanasio , Benjamin Jäger , Felix P. G. Ziegler

The equation of state (EoS), quark number density and susceptibility at nonzero quark chemical potential $\mu$ are studied in lattice QCD simulations with a clover-improved Wilson fermion of 2-flavors and RG-improved gauge action. To access…

High Energy Physics - Lattice · Physics 2015-06-03 Keitaro Nagata , Atsushi Nakamura

We discuss the flavor number dependence of QCD at low temperature and high density by the complex Langevin method. In our previous work, the complex Langevin method is confirmed to satisfy the criterion for correct convergence in certain…

Thermodynamics of two-flavor QCD at finite temperature and density is studied on a $16^3 \times 4$ lattice, using a renormalization group improved gauge action and the clover improved Wilson quark action. In the simulations along lines of…

High Energy Physics - Lattice · Physics 2008-11-26 Y. Maezawa , S. Aoki , S. Ejiri , T. Hatsuda , N. Ishii , K. Kanaya , N. Ukita , T. Umeda

Quantum chromodynamics (QCD) at sufficiently high density is expected to undergo a chiral phase transition. Understanding such a transition is of particular importance for neutron star or quark star physics. In Lagrangian SU(3) lattice…

High Energy Physics - Lattice · Physics 2009-11-07 Yi-Zhong Fang , Xiang-Qian Luo

We confront our quasi-particle model for the equation of state of strongly interacting matter with recent first-principle QCD calculations. In particular, we test its applicability at finite baryon densities by comparing with Taylor…

High Energy Physics - Phenomenology · Physics 2011-09-13 Marcus Bluhm , Burkhard Kampfer , Robert Schulze , Daniel Seipt

We study the use of the complex-Langevin equation (CLE) to simulate lattice QCD at a finite chemical potential ($\mu$) for quark-number, which has a complex fermion determinant that prevents the use of standard simulation methods based on…

High Energy Physics - Lattice · Physics 2019-10-02 J. B. Kogut , D. K. Sinclair

The equation of state of Quantum Chromodynamics (QCD) at finite density is currently known only in a limited range in the baryon chemical potential $\mu_B$. This is due to fundamental shortcomings of traditional methods such as Taylor…

We study QCD in 2 dimensions using the improved lattice fermionic Hamiltonian proposed by Luo, Chen, Xu and Jiang. The vector mass and the chiral condensate are computed for various $SU(N_C)$ gauge groups. We do observe considerable…

High Energy Physics - Lattice · Physics 2009-10-31 Xiang-Qian Luo , J. Jiang , S. Guo , J. Li , J. Liu , Z. Mei , H. Jirari , H. Kroger , C. M. Wu

We investigate high density state of SU(2) QCD in the case of the Wilson fermions with Iwasaki improved action. Based on the Woodbery formula, the ratio of fermion determinants is evaluated at each step of the Metropolis link update. At…

High Energy Physics - Lattice · Physics 2007-05-23 S. Muroya , A. Nakamura , C. Nonaka

The problem of unphysical zero modes in lattice QCD with Wilson fermions can be solved in a clean way by including a mass term proportional to $i \psibar \gamma_5 \tau^3 \psi$ in the standard lattice theory with Nf=2 mass degenerate Wilson…

High Energy Physics - Lattice · Physics 2015-06-25 Roberto Frezzotti , Pietro Antonio Grassi , Stefan Sint , Peter Weisz

We test an algebraic algorithm based on the coordinate-space method, evaluating with high accuracy the critical mass for Wilson fermions in lattice QCD at two loops. We test the results by using different types of infrared regularization.

High Energy Physics - Lattice · Physics 2007-05-23 Sergio Caracciolo , Andrea Pelissetto , Antonio Rago

We present selected results obtained by RQCD from simulations of $N_f=2+1$ flavours of non-perturbatively $\mathcal{O}(a)$ improved Wilson fermions, employing open boundary conditions in time. The ensembles were created within the CLS…

We first test the Complex Langevin method (CLE) on various simple models. We then introduce the method of Gauge Cooling to control the dynamics of the process and ensure thin distributions in the imaginary direction. We finally apply CLE…

High Energy Physics - Lattice · Physics 2013-10-29 Gert Aarts , Lorenzo Bongiovanni , Erhard Seiler , Denes Sexty , Ion-Olimpiu Stamatescu

Long-range interactions in finite density QCD necessitate a non-perturbative approach in order to reliably map out the key features and spectrum of the QCD phase diagram. However, the complex nature of the fermion determinant in this sector…

High Energy Physics - Lattice · Physics 2008-11-26 A. Dougall

Lattice QED2 with the Wilson formulation of fermions is used as a convenient model system to study artifacts of the quenched approximation on a finite lattice. The quenched functional integral is shown to be ill-defined in this system as a…

High Energy Physics - Lattice · Physics 2009-10-30 W. Bardeen , A. Duncan , E. Eichten , H. Thacker