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Related papers: Triage of the Sign Problem

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Attempts to extract the order of the chiral transition of QCD at zero chemical potential, with two dynamical flavors of massless quarks, from simulations with progressively decreasing pion mass have remained inconclusive because of their…

High Energy Physics - Lattice · Physics 2018-11-13 Francesca Cuteri , Owe Philipsen , Alessandro Sciarra

In addition to temperature and baryon chemical potential there are other parameters that matter in the real quark matter. One of them is isospin asymmetry which does exist in nature, for example, in the compact stars and in heavy ion…

High Energy Physics - Phenomenology · Physics 2020-01-08 T. G. Khunjua , K. G. Klimenko , R. N. Zhokhov

As was shown by Leutwyler and Smilga, the fact that chiral symmetry is broken and the existence of a effective finite volume partition function leads to an infinite number of sum rules for the eigenvalues of the Dirac operator in QCD. In…

High Energy Physics - Theory · Physics 2009-09-25 Jacobus Verbaarschot

We study the quark-mass dependence of the QCD critical point at varying bare up/down quark masses with fixed strange quark mass. We explore the corresponding second-order critical surface in the three-dimensional Columbia plot and study the…

High Energy Physics - Phenomenology · Physics 2025-08-06 Julian Bernhardt , Christian S. Fischer

In this proceeding we present our first results of the study of the QCD Equation of State at non-zero baryon density and in external magnetic field. We focused on the first three non-vanishing expansion coefficients of pressure in chemical…

High Energy Physics - Lattice · Physics 2022-04-13 N. Yu. Astrakhantsev , V. V. Braguta , N. V. Kolomoyets , A. Yu. Kotov , A. A. Roenko

We investigate the Euclidean path integral formulation of QCD at finite baryon density and temperature. We show that the partition function Z can be written as a difference between two sums Z+ and Z-, each of which defines a partition…

High Energy Physics - Theory · Physics 2010-02-05 Stephen D. H. Hsu , David Reeb

We link the spontaneous breakdown of chiral symmetry in Euclidean QCD to the collision of spectral shock waves in the vicinity of zero eigenvalue of Dirac operator. The mechanism, originating from complex Burger's-like equation for viscid,…

High Energy Physics - Phenomenology · Physics 2015-12-23 Jean-Paul Blaizot , Maciej A. Nowak , Piotr Warchoł

In this lecture we discuss correlations of the QCD Dirac eigenvalues. We find that below a scale of $E_c\sim \Lambda/L^2$ they are given by chiral Random Matrix Theory. This follows from analytical arguments based on partially quenched…

High Energy Physics - Theory · Physics 2007-05-23 J. J. M. Verbaarschot

We introduce a new non-Hermitian random matrix model for QCD with a baryon chemical potential. This model is a direct chiral extension of a previously studied model that interpolates between the Wigner-Dyson and Ginibre ensembles. We…

High Energy Physics - Theory · Physics 2009-11-10 James C. Osborn

The notorious sign problem severely limits the applicability of quantum Monte Carlo (QMC) simulations, as statistical errors grow exponentially with system size and inverse temperature. A recent proposal of a quantum-computing stochastic…

Quantum Physics · Physics 2026-03-11 Kwai-Kong Ng , Min-Fong Yang

The chiral symmetry of QCD is studied at finite temperature and chemical potential using the Schwinger-Dyson equation in the improved ladder approximation. We calculate three order parameters; the vacuum expectation value of the quark…

High Energy Physics - Phenomenology · Physics 2009-10-28 Yusuke Taniguchi , Yuhsuke Yoshida

We employ non-perturbative flow equations to compute the equation of state for two flavor QCD within an effective quark meson model. Our treatment covers both the chiral perturbation theory domain of validity and the domain of validity of…

High Energy Physics - Phenomenology · Physics 2007-05-23 J. Berges

We propose a random matrix theory for QCD in three dimensions with a Chern-Simons term at level $k$ which spontaneously breaks the flavor symmetry according to U($2N_{\rm f}$) $\to $ U($N_{\rm f}+k$)$\times$U($N_{\rm f}-k$). This random…

High Energy Physics - Theory · Physics 2019-10-22 Takuya Kanazawa , Mario Kieburg , Jacobus J. M. Verbaarschot

We use the linear sigma model with quarks to study the QCD phase diagram from the point of view of chiral symmetry restoration. We compute the leading order effective potential for high and low temperatures and finite quark chemical…

High Energy Physics - Phenomenology · Physics 2018-01-31 Alejandro Ayala , Saul Hernandez-Ortiz , Luis A. Hernandez

According to the generally accepted phase diagram of QCD, at low temperature and high baryon number density the chiral phase transition of QCD is of first order and the co-existence of the Nambu-Goldstone phase and the Wigner phase should…

High Energy Physics - Phenomenology · Physics 2015-05-28 Yu Jiang , Hao Gong , Wei-min Sun , Hong-shi Zong

We incorporate chiral symmetry breaking in a soft-wall version of the AdS/QCD model by using a modified dilaton profile and a quartic term in the bulk scalar potential. This allows one to separate the dependence on spontaneous and explicit…

High Energy Physics - Phenomenology · Physics 2015-05-13 Joseph I. Kapusta , Thomas M. Kelley , Tony Gherghetta

The conventional view is that a solution of the strong CP problem lies beyond QCD. A strong argument supporting this view is that the chiral expansion shows that observables depend on theta (unless a quark mass is zero); this eliminates the…

High Energy Physics - Phenomenology · Physics 2019-05-15 Thomas D. Cohen

We study a random matrix model for QCD at finite density via complex Langevin dynamics. This model has a phase transition to a phase with nonzero baryon density. We study the convergence of the algorithm as a function of the quark mass and…

High Energy Physics - Lattice · Physics 2017-04-05 Jacques Bloch , Jonas Glesaaen , Owe Philipsen , Jacobus Verbaarschot , Savvas Zafeiropoulos

Despite its tremendous success, the Standard Model of particle physics does not explain why the weak interaction breaks chiral symmetry. Various unified theories got us closer to an answer, but too often the explanation consists of labeling…

High Energy Physics - Theory · Physics 2020-05-19 Ovidiu Cristinel Stoica

We present a phase diagram study of the O(4) model as an effective theory for 2-flavor QCD. In the chiral limit, both theories perform spontaneous symmetry breaking with isomorphic groups, which suggests that they belong to the same…