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Related papers: Statistical QCD with non-positive measure

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We investigate inhomogeneous chiral condensates, such as the so-called dual chiral density wave of dense quark matter, under an external magnetic field at finite real and imaginary chemical potentials. In a model-independent manner, we find…

High Energy Physics - Phenomenology · Physics 2015-08-04 Kouji Kashiwa , Tong-Gyu Lee , Kazuya Nishiyama , Ryo Yoshiike

We investigate the eigenvalue spectrum of the staggered Dirac matrix in full QCD with two colors and finite chemical potential. Along the strong-coupling axis up to the temperature phase transition, the low-lying Dirac spectrum is well…

High Energy Physics - Lattice · Physics 2007-05-23 Elmar Bittner , Maria-Paola Lombardo , Harald Markum , Rainer Pullirsch

Monte Carlo simulations of finite density systems are often plagued by the complex action problem. We point out that there exists certain non-commutativity in the zero chemical potential limit and the thermodynamic limit when one tries to…

High Energy Physics - Lattice · Physics 2009-11-10 Jan Ambjorn , Konstantinos N. Anagnostopoulos , Jun Nishimura , Jacobus J. M. Verbaarschot

The chiral condensate, which is constant in vacuum, may become spatially modulated at moderately high densities where in the traditional picture of the QCD phase diagram a first-order chiral phase transition occurs. We review the current…

High Energy Physics - Phenomenology · Physics 2015-06-19 Michael Buballa , Stefano Carignano

We consider a lattice-inspired random matrix model for the QCD chiral phase transition at finite chemical potential. Useful features of the usual RMM for QCD at finite chemical potential are reobtained, some being brought closer to their…

High Energy Physics - Lattice · Physics 2007-05-23 M. A. Halasz

The nature of the chiral phase transition of QCD continues to represent a fundamental open problem in the study of strongly interacting matter. In recent years, significant progress has been achieved by exploiting systematic variations of…

High Energy Physics - Lattice · Physics 2025-12-23 Alessandro Sciarra

We propose a framework for quantitative evaluation of dynamical tendency for polarization in arbitrary random variable that can be decomposed into a pair of orthogonal subspaces. The method uses measures based on comparisons of given…

High Energy Physics - Lattice · Physics 2011-08-05 Andrei Alexandru , Terrence Draper , Ivan Horvath , Thomas Streuer

The expectation value of the complex phase factor of the fermion determinant is computed in the microscopic domain of QCD at nonzero chemical potential. We find that the average phase factor is non-vanishing below a critical value of the…

High Energy Physics - Lattice · Physics 2008-11-26 K. Splittorff , J. J. M. Verbaarschot

Inhomogeneous chiral phase is discussed in the presence of the magnetic field. A topological aspect is pointed out for the complex order parameter, in relation to the spectral asymmetry of the Dirac operator. It induces an anomalous baryon…

High Energy Physics - Phenomenology · Physics 2015-06-18 T. Tatsumi , K. Nishiyama , S. Karasawa

We investigate the effects of a finite chemical potential $\mu$ in QCD viewed as a disordered medium. In the quenched approximation, $A_4=i\mu$ induces a complex electric Aharonov-Bohm effect that causes the diagonal contribution to the…

High Energy Physics - Phenomenology · Physics 2009-10-31 Romuald A. Janik , Maciej A. Nowak , Gabor Papp , Ismail Zahed

We compute derivatives of thermodynamic quantities with respect to $\mu$, at $\mu=0$ for 2 and 3 flavors of degenerate quark masses. This allows us to estimate the phase transition line in the $T,\mu$ plane and quantify the influence of a…

High Energy Physics - Lattice · Physics 2017-08-23 C. Schmidt

QCD monopoles are magnetically charged quasiparticles whose Bose-Einstein condensation (BEC) at $T<T_c$ creates electric confinement and flux tubes. The "magnetic scenario" of QCD proposes that scattering on the non-condensed component of…

High Energy Physics - Phenomenology · Physics 2019-07-24 Adith Ramamurti , Edward Shuryak

The Banks-Casher relation links the spectral density of the Dirac operator with the existence of a chiral condensate and spontaneous breaking of chiral symmetry. This relation receives corrections from a finite value of the quark mass, a…

High Energy Physics - Lattice · Physics 2013-02-25 S. Necco , A. Shindler

A method for obtaining the low chemical potential dependence of the dressed quark propagator from an effective quark-quark interaction model is developed. From this the chemical potential dependence of the chiral quark condensate and bag…

Nuclear Theory · Physics 2009-11-07 Hong-shi Zong , Jia-lun Ping , Wei-min Sun , Fang Wang , Chao-hsi Chang

A chiral fermion action allows one to do very clean studies of chiral symmetry breaking in QCD. I will briefly describe how to compute with the overlap action (relatively) cheaply, and then turn to physics: Low modes of the Dirac operator…

High Energy Physics - Lattice · Physics 2007-05-23 Thomas DeGrand

The spontaneous breaking of chiral symmetry in QCD is known to be linked to a non-zero density of eigenvalues of the massless Dirac operator near the origin. Numerical studies of two-flavour QCD now suggest that the low quark modes are…

High Energy Physics - Lattice · Physics 2008-11-26 Martin Lüscher

The QCD phase diagram is studied in the presence of an isospin asymmetry using continuum extrapolated staggered quarks with physical masses. In particular, we investigate the phase boundary between the normal and the pion condensation…

High Energy Physics - Lattice · Physics 2018-04-04 B. B. Brandt , G. Endrodi , S. Schmalzbauer

In this contribution we investigate the phase diagram of QCD in the presence of an isospin chemical potential. To alleviate the infrared problems of the theory associated with pion condensation, we introduce the pionic source as an infrared…

High Energy Physics - Lattice · Physics 2016-11-22 Bastian B. Brandt , Gergely Endrodi

The behaviour of the chiral condensate in QCD is investigated by means of a study of the distribution of the zeros of the partition function in the complex quark mass plane. Simulations are performed at fixed temperature on three different…

High Energy Physics - Lattice · Physics 2009-10-22 I. M. Barbour , A. J. Bell , E. G. Klepfish

We investigate the universal features of chiral symmetry breaking in large-$N$ QCD by comparing non-perturbative determinations of the low-lying Dirac spectrum with chiral Random Matrix Theory (RMT) predictions. Our numerical Monte Carlo…