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Related papers: Chiral expansions of the pi0 lifetime

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We study the use of NLO and NNLO formulae from SU(2) chiral perturbation theory to fit results from the 2+1 flavor DWF QCD ensembles that have been generated by the RBC and UKQCD collaborations. These ensembles are at two different lattice…

High Energy Physics - Lattice · Physics 2019-08-14 Robert Mawhinney

We discuss chiral perturbation theory for two and three quark flavors in the epsilon expansion at next-to-next-to-leading order (NNLO) including a small imaginary chemical potential. We calculate finite-volume corrections to the low-energy…

High Energy Physics - Lattice · Physics 2014-11-20 Christoph Lehner , Shoji Hashimoto , Tilo Wettig

Chiral logarithms in $m_\pi^2$ are calculated at one loop, taking into account the leading contributions to flavor symmetry breaking due to staggered fermions. I treat both the full QCD case (2+1 light dynamical flavors) and the quenched…

High Energy Physics - Lattice · Physics 2008-11-26 C. Bernard

We test the convergence property of the chiral perturbation theory (ChPT) using a lattice QCD calculation of pion mass and decay constant with two dynamical quark flavors. The lattice calculation is performed using the overlap fermion…

High Energy Physics - Lattice · Physics 2019-08-14 J. Noaki , S. Aoki , T. W. Chiu , H. Fukaya , S. Hashimoto , T. H. Hsieh , T. Kaneko , H. Matsufuru , T. Onogi , E. Shintani , N. Yamada

In this paper we use one-loop chiral perturbation theory in order to compare lattice computations of the K+ to pi+ pi0 decay amplitude with the experimental value. This makes it possible to investigate three systematic effects that plague…

High Energy Physics - Lattice · Physics 2016-08-24 Maarten Golterman , Ka Chun Leung

Simulations with 2+1 flavors of domain wall fermions provide us with the opportunity to compare the lattice data directly to the predictions of continuum chiral perturbation theory, up to corrections from the residual chiral symmetry…

High Energy Physics - Lattice · Physics 2009-11-13 Meifeng Lin

We present the ingredients for determining $K^{+}\to\pi^{+}\pi^{0}$ matrix elements via the combination of lattice QCD and chiral perturbation theory ($\chi$PT). By simulating these matrix elements at unphysical kinematics, it is possible…

High Energy Physics - Lattice · Physics 2008-11-26 C. -J. D. Lin , G. Martinelli , E. Pallante , C. T. Sachrajda , G. Villadoro

We compute the imaginary part of the 2-loop vertex corrections in the QCD Factorization framework for hadronic two-body decays as B -> pi pi. This completes the NNLO calculation of the imaginary part of the topological tree amplitudes and…

High Energy Physics - Phenomenology · Physics 2008-11-26 Guido Bell

We present the scattering lengths for the $\pi K$ processes in the three flavour Chiral Perturbation Theory (ChPT) framework at next-to-next-to-leading order (NNLO). The calculation has been performed analytically but we only include…

High Energy Physics - Phenomenology · Physics 2011-03-22 Johan Bijnens , Pierre Dhonte , Pere Talavera

A calculation of the pion mass and decay constant at NNNLO in two-flavour chiral perturbation theory is presented. The results are cross-checked by using both the exponential and square root parameterizations of the Goldstone matrix field,…

High Energy Physics - Phenomenology · Physics 2018-01-17 Johan Bijnens , Nils Hermansson Truedsson

We present a calculation of the finite volume corrections to meson masses and decay constants in three flavour Partially Quenched Chiral Perturbation Theory (PQChPT) through two-loop order in the chiral expansion for the flavour-charged (or…

High Energy Physics - Lattice · Physics 2016-01-20 Johan Bijnens , Thomas Rössler

We compute the scattering amplitude in Wilson Chiral Perturbation Theory for two flavors. The lattice spacing effects due to the explicit chiral symmetry breaking are kept through O(a^2), and we consider the regime where the quark mass m is…

High Energy Physics - Lattice · Physics 2010-01-21 Sinya Aoki , Oliver Bar , Benedikt Biedermann

We study the decays $K\to\pi\pi$ in one-loop two-flavour Chiral Perturbation Theory. We provide arguments why the calculation of the coefficient of the pionic chiral logarithm $\logm = M^2\log M^2$ is unique and then perform the…

High Energy Physics - Phenomenology · Physics 2009-10-06 Johan Bijnens , Alejandro Celis

We compute chiral logarithms in the presence of "taste" symmetry breaking of staggered fermions. The lagrangian of Lee and Sharpe is generalized and then used to calculate the logs in $\pi$ and $K$ masses. We correct an error in Ref. [1]…

High Energy Physics - Lattice · Physics 2008-11-26 C. Aubin , C. Bernard , C. DeTar , Steven Gottlieb , Urs M. Heller , K. Orginos , R. Sugar , D. Toussaint

I discuss the properties of pions in ``partially quenched'' theories, i.e. those in which the valence and sea quark masses, $m_V$ and $m_S$, are different. I point out that for lattice fermions which retain some chiral symmetry on the…

High Energy Physics - Lattice · Physics 2014-11-17 Stephen R. Sharpe

The colour-suppressed tree amplitude in non-leptonic B decays is particularly sensitive to perturbative and non-perturbative corrections. We calculate the two-loop (NNLO) vertex corrections to the colour-suppressed and colour-allowed tree…

High Energy Physics - Phenomenology · Physics 2014-11-20 M. Beneke , T. Huber , Xin-Qiang Li

We present results for the O(alpha_s) virtual corrections to q g -> W b bbar q' obtained with a new automatized approach to the evaluation of one-loop amplitudes in terms of Feynman diagrams. Together with the O(alpha_s) corrections to q q'…

High Energy Physics - Phenomenology · Physics 2015-05-30 Laura Reina , Thomas Schutzmeier

We calculate the finite volume corrections to meson masses and decay constants in two and three flavour Chiral Perturbation Theory to two-loop order. The analytical results are compared with the existing result for the pion mass in…

High Energy Physics - Lattice · Physics 2015-06-23 Johan Bijnens , Thomas Rössler

We argue that light quark loops produce a paramagnetic suppression of infrared-sensitive order parameters such as <qq>, as the number N_f of light fermions increases. The possibly strong dependence of <qq> on N_f is related to the observed…

High Energy Physics - Phenomenology · Physics 2009-10-31 Sebastien Descotes , Luca Girlanda , Jan Stern

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
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