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Related papers: Unphysical Operators in Partially Quenched QCD

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We calculate the kaon B-parameter, B_K, to next-to-leading order in staggered chiral perturbation theory. We find expressions for partially quenched QCD with three sea quarks, quenched QCD, and full QCD with m_u = m_d but not equal to m_s.…

High Energy Physics - Lattice · Physics 2009-11-11 Ruth S. Van de Water , Stephen R. Sharpe

The dependence of the pseudoscalar meson masses and decay constants on sea and valence quark masses is compared to next-to-leading order (NLO) Chiral Perturbation Theory (ChPT). The numerical simulations with two light dynamical quark…

High Energy Physics - Lattice · Physics 2008-11-26 F. Farchioni , I. Montvay , E. Scholz , L. Scorzato

Different versions of improved staggered fermions can be used as valence quarks to reduce discretization effects in lattice QCD calculations while increasing statistics on existing staggered gauge ensembles. Such mixed-action simulations…

High Energy Physics - Lattice · Physics 2013-11-26 Jon A. Bailey , Jongjeong Kim , Weonjong Lee , Hyung-Jin Kim , Boram Yoon

The masses of baryons containing a heavy quark are calculated to next-to-leading order in partially quenched heavy hadron chiral perturbation theory. Calculations are performed for three light flavors in the isospin limit and additionally…

High Energy Physics - Lattice · Physics 2009-11-10 Brian C. Tiburzi

We study the structure of mass terms in the effective theory for quasi-particles in QCD at high baryon density. To next-to-leading order in the $1/p_F$ expansion we find two types of mass terms, chirality conserving two-fermion operators…

High Energy Physics - Phenomenology · Physics 2009-11-07 Thomas Schaefer

We calculate results for K to pi and K to 0 matrix elements to next-to-leading order in 2+1 flavor partially quenched chiral perturbation theory. Results are presented for both the Delta I=1/2 and 3/2 channels, for chiral operators…

High Energy Physics - Lattice · Physics 2009-02-23 C. Aubin , J. Laiho , S. Li , M. F. Lin

In the limit of vanishing up, down and strange quark masses, QCD exhibits a chiral symmetry. This symmetry is broken spontaneously to its vector subgroup, giving rise to Goldstone bosons. These acquire a small mass through the explicit…

High Energy Physics - Phenomenology · Physics 2024-12-31 Ulf-G. Meißner

In the calculation of non-leptonic weak decay rates, a "mismatch" arises when the QCD evolution of the relevant weak hamiltonian down to hadronic scales is performed in unquenched QCD, but the hadronic matrix elements are then computed in…

High Energy Physics - Lattice · Physics 2010-02-03 Maarten Golterman , Elisabetta Pallante

The anomalous Lagrangian in mesonic Chiral Perturbation Theory, of odd intrinsic parity, is determined to next-to-next-to-leading order thereby completing the order $p^8$ Lagrangian. A schematic view of its construction with the MINIBAR…

High Energy Physics - Phenomenology · Physics 2023-12-06 Johan Bijnens , Nils Hermansson-Truedsson , Joan Ruiz-Vidal

We construct the U_L(3) x U_R(3) effective lagrangian which encodes the dynamics of the low energy pseudoscalar excitations in the Color-Flavor-Locking superconducting phase of QCD at finite quark density. We include the effects of…

High Energy Physics - Phenomenology · Physics 2009-10-31 Cristina Manuel , Michel H. G. Tytgat

We extend to quenched QCD an earlier investigation of the chiral structure of the masses of the nucleon and the delta in lattice simulations of full QCD. Even after including the meson-loop self-energies which give rise to the leading and…

High Energy Physics - Lattice · Physics 2010-02-17 R. D. Young , D. B. Leinweber , A. W. Thomas , S. V. Wright

Progress in computing the spectrum of excited baryons and mesons in lattice QCD is described. Large sets of spatially-extended hadron operators are used. The need for multi-hadron operators in addition to single-hadron operators is…

High Energy Physics - Lattice · Physics 2015-05-30 Colin Morningstar , John Bulava , Justin Foley , You-Cyuan Jhang , Keisuke Juge , David Lenkner , Chik Him Wong

We have performed fits of the pseudoscalar masses and decay constants, from a variety of RBC-UKQCD domain wall fermion ensembles, to $SU(2)$ partially quenched chiral perturbation theory at next-to leading order (NLO) and next-to-next-to…

High Energy Physics - Lattice · Physics 2016-03-23 P. A. Boyle , N. H. Christ , N. Garron , C. Jung , A. Jüttner , C. Kelly , R. D. Mawhinney , G. McGlynn , D. J. Murphy , S. Ohta , A. Portelli , C. T. Sachrajda

We examine the spectrum of 2-colour lattice QCD with 4 continuum flavours at a finite chemical potential ($\mu$) for quark-number, on a $12^3 \times 24$ lattice. First we present evidence that the system undergoes a transition to a state…

High Energy Physics - Lattice · Physics 2009-11-10 J. B. Kogut , D. Toublan , D. K. Sinclair

For a low-temperature expansion in QCD it is well-known that the Lagrangian of vacuum chiral perturbation theory can be applied. This is due to the fact that the thermal effects of the heavy modes are Boltzmann suppressed. The present work…

High Energy Physics - Phenomenology · Physics 2007-05-23 Stefan Leupold

This paper summarizes the recent calculations of the masses and decay constants of the pseudoscalar mesons at the two-loop level, or NNLO, in Partially Quenched Chiral Perturbation Theory (PQxPT). Possible applications include chiral…

High Energy Physics - Lattice · Physics 2009-11-11 Timo A. Lahde , Johan Bijnens , Niclas Danielsson

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

We investigate the nonperturbative renormalisation of composite operators in lattice QCD restricting ourselves to operators that are bilinear in the quark fields. These include operators which are relevant to the calculation of moments of…

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

The chiral effective meson-baryon Lagrangian for the description of interactions between the doubly charmed baryons and Goldstone bosons is constructed up to the order of $q^{4}$. The numbers of linearly independent invariant monomials of…

High Energy Physics - Phenomenology · Physics 2021-02-17 Peng-Cheng Qiu , De-Liang Yao

This thesis is dedicated to explore the feasibility of numerical calculations in the $\epsilon$--regime of QCD for the extraction of physical information. We apply two formulations of the Ginsparg-Wilson fermions the Neuberger operator and…

High Energy Physics - Lattice · Physics 2007-05-23 S. Shcheredin