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A parameter free, model independent analysis of quark mass matrices is carried out. We find a representation in terms of a diagonal mass matrix for the down (up) quarks and a suitable matrix for the up (down) quarks, such that the mass…

High Energy Physics - Phenomenology · Physics 2011-02-01 D. Falcone , O. Pisanti , L. Rosa

We derive the chiral effective Lagrangian for heavy-light mesons in the heavy quark limit from QCD under proper approximations. The low energy constants in the effective Lagrangian are expressed in terms of the light quark self-energy. With…

High Energy Physics - Phenomenology · Physics 2020-09-02 Qing-Sen Chen , Hui-Feng Fu , Yong-Liang Ma , Qing Wang

A bottom-up approach has been adopted to identify a flavour model that agrees with present experimental measurements. The charged fermion mass hierarchies suggest that only the top Yukawa term should be present at the renormalisable level.…

High Energy Physics - Phenomenology · Physics 2022-09-21 L. Merlo

QCD lattice simulations with 2+1 flavours (when two quark flavours are mass degenerate) typically start at rather large up-down and strange quark masses and extrapolate first the strange quark mass and then the up-down quark mass to its…

We study properties of pseudoscalar flavour-singlet mesons from Wilson twisted mass lattice QCD with Nf=2+1+1 dynamical quark flavors. Results for masses are presented at three values of the lattice spacing and light quark masses…

A physically defined QCD coupling parameter naturally incorporates massive quark flavor thresholds in a gauge invariant, renormalization scale independent and analytical way. In this paper we summarize recent results for the finite-mass…

High Energy Physics - Phenomenology · Physics 2009-10-31 Michael Melles

A first study of critical behavior in the vicinity of the chiral phase transition of (2+1)-flavor QCD is presented. We analyze the quark mass and volume dependence of the chiral condensate and chiral susceptibilities in QCD with two…

High Energy Physics - Lattice · Physics 2014-11-20 S. Ejiri , F. Karsch , E. Laermann , C. Miao , S. Mukherjee , P. Petreczky , C. Schmidt , W. Soeldner , W. Unger

We extend a known method to integrate out the strange quark in three flavour chiral perturbation theory to the context of an arbitrary number of flavours. As an application, we present the explicit formulae to one--loop accuracy for the…

High Energy Physics - Phenomenology · Physics 2011-09-23 Mikhail A. Ivanov , Martin Schmid

We summarize developments concerning the quark mass dependence of nucleon magnetic moments and the axial-vector coupling constant g_A. The aim is to explore the feasibility of chiral effective field theory methods for the extrapolation of…

High Energy Physics - Lattice · Physics 2009-11-10 Thomas R. Hemmert , Massimiliano Procura , Wolfram Weise

We present a computation of the charm quark's mass and the leptonic D-meson decay constants f_D and f_{D_s} in two-flavour lattice QCD with non-perturbatively O(a) improved Wilson quarks. Our analysis is based on the CLS configurations at…

High Energy Physics - Lattice · Physics 2013-12-31 Jochen Heitger , Georg M. von Hippel , Stefan Schaefer , Francesco Virotta

We present results for the light quark masses in lattice QCD with two degenerate flavours of dynamical fermions. We used configurations generated by the UKQCD and QCDSF collaborations at six different combinations of beta and kappa_sea.

High Energy Physics - Lattice · Physics 2009-10-31 D. Pleiter , QCDSF Collaboration , UKQCD Collaboration

We compare analytic predictions of non-Hermitian chiral random matrix theory with the complex Dirac operator eigenvalue spectrum of two-colour lattice gauge theory with dynamical fermions at nonzero chemical potential. The Dirac eigenvalues…

High Energy Physics - Lattice · Physics 2009-11-11 G. Akemann , E. Bittner

Lattice simulations for (2+1)-flavor QCD with external magnetic field demonstrated that the quark mass is one of the important parameters responsible for the (inverse) magnetic catalysis. We discuss the dependences of chiral condensates and…

High Energy Physics - Lattice · Physics 2018-04-18 Akio Tomiya , Heng-Tong Ding , Swagato Mukherjee , Christian Schmidt , Xiao-Dan Wang

QCD with three degenerate quark flavours at zero baryon density exhibits a first order thermal phase transition for small quark masses, which changes to a smooth crossover for some critical quark mass m^c_0, i.e. the chiral critical point.…

High Energy Physics - Lattice · Physics 2008-11-26 Philippe de Forcrand , Owe Philipsen

A fully non-perturbative lattice determination of the up/down and strange quark masses is given for quenched QCD using both, $O(a)$ improved Wilson fermions and ordinary Wilson fermions. For the strange quark mass with $O(a)$ improved…

High Energy Physics - Lattice · Physics 2008-11-26 M. Gockeler , R. Horsley , H. Oelrich , D. Petters , D. Pleiter , P. E. L. Rakow , G. Schierholz , P. Stephenson

We consider two-flavor asymmetric QCD combined with a low-energy effective model inspired by chiral perturbation theory and lattice data to investigate the effects of masses, isospin and baryon number on the pressure and the deconfinement…

High Energy Physics - Phenomenology · Physics 2009-03-23 L. F. Palhares , E. S. Fraga , C. Villavicencio

We present the results of the physical point simulation in 2+1 flavor lattice QCD with the nonperturbatively $O(a)$-improved Wilson quark action and the Iwasaki gauge action at $\beta=1.9$ on a $32^3 \times 64$ lattice. The physical quark…

We present results of computing the p6 order low energy constants in the normal part of chiral Lagrangian both for two and three flavor pseudo-scalar mesons. This is a generalization of our previous work on calculating the p4 order…

High Energy Physics - Phenomenology · Physics 2014-11-20 Shao-Zhou Jiang , Ying Zhang , Chuan Li , Qing Wang

As is pointed out in a recent work (Phys. Rev. Lett. 120, 222001), quark matter may not be strange. Inspired by this argument, we use a new self-consistent mean field approximation method to study the equation of state of cold dense matter…

Nuclear Theory · Physics 2019-08-26 Tong Zhao , Wei Zheng , Fei Wang , Cheng-Ming Li , Yan Yan , Yong-Feng Huang , Hong-Shi Zong

We study the phase structure of mixed-action QCD with two Wilson sea quarks and two chiral valence quarks, starting from the chiral lagrangian. A priori, the effective theory allows for a rich phase structure, including a phase with a…

High Energy Physics - Lattice · Physics 2011-10-13 Oliver Baer , Maarten Golterman , Yigal Shamir