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Related papers: U(1) Problem at Finite Temperature

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In order to quantify the universal properties of the chiral phase transition in (2+1)-flavor QCD, we make use of an improved, renormalized order parameter for chiral symmetry breaking which is obtained as a suitable difference of the…

High Energy Physics - Lattice · Physics 2024-11-28 Sabarnya Mitra , Frithjof Karsch , Sipaz Sharma

Violation of the $U(1)$ axial symmetry in QCD is stricter than the chiral $SU(2)$ breaking, simply because of the presence of the quantum axial anomaly. If the QCD gauge coupling is sent to zero, the strength of the $U(1)$ axial breaking…

High Energy Physics - Phenomenology · Physics 2024-03-12 Chuan-Xin Cui , Mamiya Kawaguchi , Jin-Yang Li , Shinya Matsuzaki , Akio Tomiya

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 several aspects of chiral symmetry in QCD at a temperature of $T = 128\,\text{MeV}$. The study is based on a $24\times 96^3$ lattice-QCD ensemble with O($a$)-improved Wilson quarks and physical up, down and strange quark…

High Energy Physics - Lattice · Physics 2023-04-05 Marco Cè , Tim Harris , Ardit Krasniqi , Harvey B. Meyer , Csaba Török

We perform hybrid Monte-Carlo (HMC) simulation of lattice QCD with $N_f=2+1+1$ domain-wall quarks at the physical point, on the $64^3 \times (64,20,16,12,10,8,6)$ lattices, each with three lattice spacings. The lattice spacings and the bare…

High Energy Physics - Lattice · Physics 2022-10-13 Yu-Chih Chen , Ting-Wai Chiu , Tung-Han Hsieh

We reinvestigate constraints on the eigenvalue density of the Dirac operator in the chiral symmetric phase of 2 flavor QCD at finite temperature, employing the overlap Dirac operator with the exact chiral symmetry at finite lattice spacings…

High Energy Physics - Lattice · Physics 2012-12-10 Sinya Aoki , Hidenori Fukaya , Yusuke Taniguchi

We use a modified directed path algorithm to study the finite temperature chiral singularities of two color lattice QCD with staggered fermions at strong coupling. Our lattice calculations are done at a fixed finite temperature in the…

High Energy Physics - Lattice · Physics 2008-11-26 Fu-Jiun Jiang

We study the effect of a finite quark mass on the quark number susceptibility in the framework of holographic QCD. We work in a bottom-up model with a deformed AdS black hole and D3/D7 model to calculate the quark number susceptibility at…

High Energy Physics - Phenomenology · Physics 2011-11-03 Kyung-il Kim , Youngman Kim , Shingo Takeuchi , Takuya Tsukioka

To quantify the universal properties of chiral phase transition in (2+1)-flavor QCD, we use an improved, renormalized order parameter for the chiral symmetry breaking. We construct ratios of this divergence-free order parameter from its…

High Energy Physics - Lattice · Physics 2026-02-09 Sabarnya Mitra , Frithjof Karsch

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

We determine the magnetic susceptibility of thermal QCD matter by means of first principles lattice simulations using staggered quarks with physical masses. A novel method is employed that only requires simulations at zero background field,…

High Energy Physics - Lattice · Physics 2020-07-29 Gunnar S. Bali , Gergely Endrődi , Stefano Piemonte

Multiple lattice evidences support the existence of a confining but chirally symmetric regime of QCD above the chiral symmetry restoration crossover at Tch ~ 155 MeV. This regime is characterised by an approximate chiral spin symmetry of…

High Energy Physics - Phenomenology · Physics 2024-05-08 L. Ya. Glozman , A. V. Nefediev , R. Wagenbrunn

We utilize lattice simulations of the dimensionally reduced effective field theory (EQCD) to determine the quark number susceptibility of QCD at high temperature ($T>2T_c$). We also use analytic continuation to obtain results at finite…

High Energy Physics - Lattice · Physics 2008-11-26 Ari Hietanen , Kari Rummukainen

We investigate the nature of the finite-temperature chiral transition in QCD with two light flavors, in the case of an effective suppression of the the U(1)_A symmetry breaking induced by the axial anomaly, which implies the symmetry…

High Energy Physics - Lattice · Physics 2015-07-01 Andrea Pelissetto , Ettore Vicari

We study the scaling properties of the finite temperature QCD phase transition, for light quark masses ranging from the heavy quark regime to their physical values. The lattice results are obtained in the fixed scale approach from…

High Energy Physics - Lattice · Physics 2021-11-03 A. Yu. Kotov , M. P. Lombardo , A. Trunin

The properties of net quark number fluctuations in the vicinity of the QCD chiral phase transition are discussed in terms of an effective chiral model in the mean-field approximation. We focus on the ratio of the fourth- to second- order…

High Energy Physics - Phenomenology · Physics 2009-03-27 B. Stokić , B. Friman , K. Redlich

We investigate the topological properties of unquenched $QCD$ on the basis of numerical results of simulations at fixed topological charge, recently reported by Borsanyi et al.. We demonstrate that their results for the mean value of the…

High Energy Physics - Lattice · Physics 2016-12-07 Vicente Azcoiti

It is widely believed that chiral symmetry is spontaneously broken at zero temperature in the strong coupling limit of staggered fermions, for any number of colors and flavors. Using Monte Carlo simulations, we show that this conventional…

High Energy Physics - Lattice · Physics 2012-11-15 Philippe de Forcrand , Seyong Kim , Wolfgang Unger

We study the anomalous breaking of U_A(1) symmetry just above the QCD phase transition for zero and two flavors of quarks, using a staggered fermion, lattice discretization. The properties of the QCD phase transition are expected to depend…

High Energy Physics - Lattice · Physics 2009-10-31 Shailesh Chandrasekharan , Dong Chen , Norman Christ , Weonjong Lee , Robert Mawhinney , Pavlos Vranas

Chiral symmetry restoration at nonzero temperature and quark densities are investigated in the framework of a linear sigma model with N_f=3 light quark flavors. After the derivation of the grand potential in mean-field approximation, the…

High Energy Physics - Phenomenology · Physics 2009-11-19 Bernd-Jochen Schaefer , Mathias Wagner