English
Related papers

Related papers: Quenched QCD near the chiral limit

200 papers

We analyze the chiral behavior of the hadron spectrum obtained with quenched Wilson fermions on 170 $32^3 \times 64$ lattices at $\beta = 6.0$. We calculate masses of hadrons composed of both degenerate and non-degenerate quarks. We reduce…

High Energy Physics - Lattice · Physics 2007-05-23 Tanmoy Bhattacharya , Rajan Gupta , Stephen Sharpe

We extend our lagrangian technique for chiral perturbation theory for quenched QCD to include theories in which only some of the quarks are quenched. We discuss the relationship between the partially quenched theory and a theory in which…

High Energy Physics - Lattice · Physics 2016-08-31 Claude Bernard , Maarten Golterman

We examine the chiral limit of domain wall fermions in quenched QCD. One expects that in a quenched simulation, exact fermion zero modes will give a divergent, 1/m behavior in the chiral condensate for sufficiently small valence quark…

Quenched lattice QCD simulations and quenched chiral perturbation theory are used together for this study of strangeness in the nucleon. Dependences of the matrix elements on strange quark mass, valence quark mass and momentum transfer are…

High Energy Physics - Phenomenology · Physics 2009-11-07 Randy Lewis , W. Wilcox , R. M. Woloshyn

We present results of a high statistics study of the quenched spectrum using Wilson fermions at $\beta=6.0$ on $32^3 \times 64$ lattices. We calculate the masses of mesons and baryons composed of both degenerate and non-degenerate quarks.…

High Energy Physics - Lattice · Physics 2008-02-03 Tanmoy Bhattacharya , Rajan Gupta , Gregory Kilcup , Stephen Sharpe

We compute the strange and the average up/down quark masses in the quenched approximation of lattice QCD, by using the O(a)-improved Wilson action and operators and by implementing the non-perturbative renormalization. Our computation is…

High Energy Physics - Lattice · Physics 2008-11-26 Damir Becirevic , Vittorio Lubicz , Cecilia Tarantino

Recent results for the spectrum of light hadrons provide clear evidence for the failure of quenched QCD and encouraging signs that simulations with dynamical sea quarks rectify some of the discrepancies, although string breaking has not yet…

High Energy Physics - Lattice · Physics 2009-10-31 R. D. Kenway

The vector meson mass is extracted from a large sample of partially quenched, two-flavor lattice QCD simulations. For the first time, discretisation, finite-volume and partial quenching artefacts are treated in a unified framework which is…

High Energy Physics - Lattice · Physics 2010-02-17 C. R. Allton , W. Armour , D. B. Leinweber , A. W. Thomas , R. D. Young

We review recent work by the ALPHA and UKQCD Collaborations where masses and matrix elements were computed in lattice QCD using Schr\"odinger functional boundary conditions and where the strange quark mass was determined in the quenched…

High Energy Physics - Lattice · Physics 2015-06-25 Joyce Garden , Marco Guagnelli , Jochen Heitger , Rainer Sommer , Hartmut Wittig

We study the properties of the B-->pi and B-->K transition form factors in partially quenched QCD by using the approach of partially quenched chiral perturbation theory combined with the static heavy quark limit. We show that the form…

High Energy Physics - Lattice · Physics 2014-11-17 Damir Becirevic , Sasa Prelovsek , Jure Zupan

The mass spectrum of the lowest lying octet baryons is calculated to next-to-next-to-leading order in heavy baryon chiral perturbation theory and partially quenched heavy baryon chiral perturbation theory. We work in the isospin limit and…

High Energy Physics - Lattice · Physics 2009-11-10 Andre Walker-Loud

We present an update of our study of the phase diagram of two-flavour QCD at zero baryon density with dynamical $O(a)$ improved Wilson quarks. All simulations are done on lattices with a temporal extent of $N_t=16$ and spatial extent…

High Energy Physics - Lattice · Physics 2013-11-01 Bastian B. Brandt , Anthony Francis , Harvey B. Meyer , Owe Philipsen , Hartmut Wittig

We report on simulations of quenched QCD using domain wall fermions, where we focus on basic questions about the formalism and its ability to produce expected low energy hadronic physics for light quarks. The work reported here is on…

High Energy Physics - Lattice · Physics 2009-10-31 P. Chen , N. Christ , G. Fleming , A. Kaehler , C. Malureanu , R. Mawhinney , G. Siegert , C. Sui , P. Vranas , Y. Zhestkov

We argue that consistency of the combined heavy quark and chiral effective lagrangian requires the QCD scale which multiplies $1/M$ in the heavy quark expansion to be the chiral symmetry breaking scale, $\Lambda_{CSB}$, rather than the QCD…

High Energy Physics - Phenomenology · Physics 2009-09-15 Lisa Randall , Eric Sather

We present results from simulations using 2 flavours of O(a)-improved Wilson quarks whose masses are about 1/3 of the physical strange quark mass. We present new data on the mass of the singlet pseudoscalar meson and evidence of the onset…

High Energy Physics - Lattice · Physics 2008-11-26 CR Allton , A Hart , D Hepburn , AC Irving , B Joo , C McNeile , C Michael , SV Wright

Consideration of the analytic properties of pion-induced baryon self energies leads to new functional forms for the extrapolation of light baryon masses. These functional forms reproduce the leading non-analytic behavior of chiral…

Nuclear Theory · Physics 2010-02-17 Anthony W. Thomas , Derek B. Leinweber , Kazuo Tsushima , Stewart V. Wright

The development of improved algorithms for QCD on the lattice has enabled us to do calculations at small quark masses and get control over the chiral extrapolation. Also finer lattices have become possible, however, a severe slowing down…

High Energy Physics - Phenomenology · Physics 2011-07-28 Stefan Schaefer

We have studied the light hadron spectrum and decay constants for quenched QCD at beta=6.2 on a 24^3x48 lattice. We compare the results obtained using a nearest-neighbour O(a)-improved ("clover") fermion action with those obtained using the…

High Energy Physics - Lattice · Physics 2019-06-05 UKQCD Collaboration , presented by Alan D. Simpson

The comparison of chiral perturbation theory formulae with data from lattice QCD simulations is discussed. Observables in the pion sector as well as in the baryon sector are considered, including the nucleon mass in a finite volume.

High Energy Physics - Lattice · Physics 2007-05-23 M. Göckeler

We examine artifacts associated with the chiral symmetry breaking induced through the use of Wilson-Dirac fermions in lattice Monte Carlo computations. For light quark masses, the conventional quenched theory can not be defined using direct…

High Energy Physics - Lattice · Physics 2009-10-31 W. Bardeen , A. Duncan , E. Eichten , H. Thacker