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Related papers: Random matrix analysis of the QCD sign problem for…

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The study of QCD at finite baryon density is severely hampered by the so-called fermion sign problem. As a result, we have no known first principles approach to study nuclear matter, or neutron stars from QCD. On the surface, the large Nc…

High Energy Physics - Phenomenology · Physics 2011-10-27 Aleksey Cherman , Brian C. Tiburzi

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 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

All approaches currently used to study finite baryon density lattice QCD suffer from uncontrolled systematic uncertainties in addition to the well-known sign problem. We formulate and test an algorithm, sign reweighting, that works directly…

High Energy Physics - Lattice · Physics 2020-06-24 Matteo Giordano , Kornel Kapas , Sandor D. Katz , Daniel Nogradi , Attila Pasztor

The use of known analytic results for the continuum fermion determinants in QCD and QED as benchmarks for zero lattice spacing extrapolations of lattice fermion determinants is proposed. Specifically, they can be used as a check on the…

High Energy Physics - Lattice · Physics 2009-11-10 M. P. Fry

We study an effective theory for QCD at finite temperature and density which contains the leading center symmetric and center symmetry breaking terms. The effective theory is studied in a flux representation where the complex phase problem…

High Energy Physics - Lattice · Physics 2011-07-21 Ydalia Delgado Mercado , Hans Gerd Evertz , Christof Gattringer

Recently, cluster methods have been used to solve a variety of sign problems including those that arise in the presence of fermions. In all cases an analytic partial re-summation over a class of configurations in the path integral was…

High Energy Physics - Lattice · Physics 2009-10-31 Shailesh Chandrasekharan

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…

The quantum theory of antiferromagnetism in metals is necessary for our understanding of numerous intermetallic compounds of widespread interest. In these systems, a quantum critical point emerges as external parameters (such as chemical…

Strongly Correlated Electrons · Physics 2012-12-24 Erez Berg , Max A. Metlitski , Subir Sachdev

We consider a rather general type of matrix model, where the matrix M represents a Hamiltonian of the interaction of a bosonic system with a single fermion. The fluctuations of the matrix are partly given by some fundamental randomness and…

Mathematical Physics · Physics 2017-03-27 Ivan Andric , Larisa Jonke , Danijel Jurman , Holger Bech Nielsen

The thermal restoration of chiral symmetry in QCD is known to proceed by an analytic crossover, which is widely expected to turn into a phase transition with a critical endpoint as the baryon density is increased. In the absence of a…

High Energy Physics - Lattice · Physics 2021-11-08 Owe Philipsen

I review the theoretical foundations, properties as well as the simulation results obtained so far of a variant of the Wilson lattice QCD formulation: Wilson twisted mass lattice QCD. Emphasis is put on the discretization errors and on the…

High Energy Physics - Lattice · Physics 2008-05-19 A. Shindler

We apply a random matrix model to the study of the phase diagram of QCD with two colors, two flavors, and a small quark mass. Although the effects of temperature are only included schematically, this model reproduces most of the ground…

High Energy Physics - Phenomenology · Physics 2016-09-06 Benoit Vanderheyden , A. D. Jackson

We apply the methods of Chiral Perturbation Theory to the analysis of the first moments of the Generalized Parton Distributions in a Nucleon, usually known as generalized form factors. These quantities are currently also under investigation…

High Energy Physics - Lattice · Physics 2009-04-14 Marina Dorati , Tobias A. Gail , Thomas R. Hemmert

Once the quark chemical potential $\mu$ is introduced in finite density QCD, the fermion determinant appeared in the path integral measure becomes complex. In order to investigate the phase effect of SU(3) lattice QCD (2-flavors), we…

High Energy Physics - Lattice · Physics 2009-11-10 Y. Sasai , A. Nakamura , T. Takaishi

The chiral phase transition of QCD is analyzed in a model combining random matrix elements of the Dirac operator with specially chosen non-random ones. The special form of the latter is motivated by the assumption that the fermionic…

High Energy Physics - Phenomenology · Physics 2008-11-26 Tilo Wettig , A. Schäfer , H. A. Weidenmüller

Peripheral heavy-ion collisions are expected to exhibit magnetic fields with magnitudes comparable to the QCD scale, as well as non-zero baryon densities. Whereas QCD at finite magnetic fields can be simulated directly with standard lattice…

High Energy Physics - Lattice · Physics 2024-01-05 S. Borsányi , B. B. Brandt , G. Endrődi , J. Guenther , R. Kara , A. D. M. Valois

We study the phase structure and chiral limit of $4d$ compact lattice QED with Wilson fermions (both dynamical and quenched). We use the standard Wilson action (WA) and also the modified action (MA) with some lattice artifacts suppressed.…

High Energy Physics - Lattice · Physics 2009-10-22 A. Hoferichter , V. K. Mitrjushkin , M. Müller-Preussker , Th. Neuhaus

We analyze the phase diagram of QCD with two massless quark flavors in the space of temperature, T, and chemical potential of the baryon charge, mu, using available experimental knowledge of QCD, insights gained from various models, as well…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. A. Halasz , A. D. Jackson , R. E. Shrock , M. A. Stephanov , J. J. M. Verbaarschot

We introduce Random Matrix Models for the Hermitian Wilson-Dirac operator of QCD-like theories. We show that they are equivalent to the $\epsilon$-limit of the chiral Lagrangian for Wilson chiral perturbation theory. Results are obtained…

High Energy Physics - Lattice · Physics 2013-03-14 Mario Kieburg , Jacobus J. M. Verbaarschot , Savvas Zafeiropoulos