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Related papers: The QCD Sign Problem for Small Chemical Potential

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Heavy-Dense QCD (HDQCD) is a popular theory to investigate the sign problem in quantum field theory. Besides its physical applications, HDQCD is relatively easy to implement numerically: the fermionic degrees of freedom are integrated out,…

High Energy Physics - Lattice · Physics 2016-11-07 Nicolas Garron , Kurt Langfeld

We review our results for the QCD phase diagram at baryonic chemical potential mu_B \leq pi T. Our simulations are performed with an imaginary chemical potential mu_I for which the fermion determinant is positive. For 2 flavors of staggered…

High Energy Physics - Phenomenology · Physics 2017-08-23 Ph. de Forcrand , O. Philipsen

Partition functions of two different matrix models for QCD with chemical potential are computed for an arbitrary number of quark and complex conjugate anti-quark flavors. In the large-N limit of weak nonhermiticity complete agreement is…

High Energy Physics - Theory · Physics 2010-04-05 G. Akemann , Y. V. Fyodorov , G. Vernizzi

In this lecture we discuss various aspects of QCD at nonzero chemical potential, including its phase diagram and the Dirac spectrum, and summarize what chiral random matrix theory has contributed to this subject. To illustrate the…

High Energy Physics - Phenomenology · Physics 2017-08-23 K. Splittorff , J. J. M. Verbaarschot

QCD at finite chemical potential is analytically investigated in the region of large bare fermion masses. We show that, contrary to the general wisdom, the phase of the fermion determinant is irrelevant at zero temperature. However if the…

High Energy Physics - Lattice · Physics 2009-10-31 R. Aloisio , V. Azcoiti , G. Di Carlo , A. Galante , A. F. Grillo

We propose a new method to investigate the thermal properties of QCD with a small quark chemical potential $\mu$. Derivatives of the phase transition point with respect to $\mu$ are computed at $\mu=0$ for 2 flavors of p-4 improved…

High Energy Physics - Lattice · Physics 2008-11-26 C. R. Allton , S. Ejiri , S. J. Hands , O. Kaczmarek , F. Karsch , E. Laermann , Ch. Schmidt , L. Scorzato

We discuss the distribution of the quark number over the gauge fields for QCD at nonzero quark chemical potential. As the quark number operator is non-hermitian, the distribution is over the complex plane. Moreover, because of the fermion…

High Energy Physics - Lattice · Physics 2011-07-22 M. P. Lombardo , K. Splittorff , J. J. M. Verbaarschot

We present results for the phase diagram of three flavor QCD for \mu_B ~ 500 MeV. Our simulations are performed with imaginary chemical potential \mu_I for which the fermion determinant is positive. Physical observables are then fitted by…

High Energy Physics - Lattice · Physics 2008-11-26 Ph. de Forcrand , O. Philipsen

We consider the distribution of the complex phase of the fermion determinant in QCD at nonzero chemical potential and examine the physical conditions under which the distribution takes a Gaussian form. We then calculate the baryon number as…

High Energy Physics - Lattice · Physics 2013-09-10 Jeff Greensite , Joyce C. Myers , K. Splittorff

I report on the current status of QCD phase diagram at vanishing baryon density. I focus on the QCD phase diagram with three degenerate quark flavor using Highly Improved Staggered Quarks on $N_{\tau}=6$ lattices. No evidence of a first…

High Energy Physics - Lattice · Physics 2015-06-15 Heng-Tong Ding

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

We show how the prescription of taking the absolute value of the fermion determinant in the integration measure of QCD at finite density, forgetting its phase, reproduces the correct thermodynamical limit. This prescription, which applies…

High Energy Physics - Lattice · Physics 2007-05-23 Vicente Azcoiti

We present results on the QCD phase diagram for mu_B <= pi T. Our simulations are performed with an imaginary chemical potential mu_I for which the fermion determinant is positive. On an 8^3 x 4 lattice with 2 flavors of staggered quarks,…

High Energy Physics - Lattice · Physics 2010-04-05 Ph. de Forcrand , O. Philipsen

We summarize recent results for the phase structure of QCD at finite temperature and light-quark chemical potential for N_f=2+1 and N_f=2+1+1 dynamical quark flavors. We discuss order parameters for the chiral and deconfinement transitions…

High Energy Physics - Phenomenology · Physics 2014-10-02 Christian S. Fischer , Jan Luecker , Christian A. Welzbacher

We investigate the order of the finite temperature chiral symmetry restoration transition for QCD with two massless fermions, by using a novel method, based on simulating imaginary values of the quark chemical potential…

High Energy Physics - Lattice · Physics 2014-10-30 Claudio Bonati , Philippe de Forcrand , Massimo D'Elia , Owe Philipsen , Francesco Sanfilippo

We investigate the phase of the quark determinant with finite chemical potential in lattice QCD using both analytic and numerical methods. Applying the winding number expansion and the hopping parameter expansion to the logarithm of the…

High Energy Physics - Lattice · Physics 2013-05-30 Shinji Takeda , Yoshinobu Kuramashi , Akira Ukawa

We study the scaling behavior of the (2+1)-flavor QCD crossover region towards the chiral limit with smaller-than-physical light quark mass gauge ensembles, generated using the HISQ fermion discretization. At zero chemical potential, we…

High Energy Physics - Lattice · Physics 2022-07-14 Olaf Kaczmarek , Frithjof Karsch , Anirban Lahiri , Sheng-Tai Li , Mugdha Sarkar , Christian Schmidt , Philipp Scior

At sufficiently high temperature and density, quantum chromodynamics (QCD) is expected to undergo a phase transition from the confined phase to the quark-gluon plasma phase. In the Lagrangian lattice formulation the Monte Carlo method works…

High Energy Physics - Lattice · Physics 2009-10-31 E. B. Gregory , S. Guo , H. Kroger , Xiang-Qian Luo

One of the distinctive feature of the QCD phase diagram is the possible emergence of a critical endpoint. The critical region around the critical point and the path dependency of the critical exponents is investigated within effective…

High Energy Physics - Phenomenology · Physics 2012-02-16 Bernd-Jochen Schaefer , Mathias Wagner

We present the renormalized Taylor expansion of the chiral condensate with chemical potential. The relation with the Taylor coefficients of meson susceptibilities and the quark mass dependence of the quark number susceptibilities are…

High Energy Physics - Lattice · Physics 2008-11-26 Sourendu Gupta , R. Ray