English
Related papers

Related papers: The nucleon axial-vector coupling beyond one loop

200 papers

We report on a novel scheme based on the chiral Lagrangian. It is used to analyze pion-nucleon scattering, pion photoproduction, and nucleon Compton scattering. Subthreshold partial-wave amplitudes are calculated in chiral perturbation…

High Energy Physics - Phenomenology · Physics 2015-05-20 A. M. Gasparyan , M. F. M. Lutz

We compute the polarisability of the nucleon to leading order in chiral perturbation theory. The contributions from kaons and baryon resonances as intermediate states are included in addition to the contribution from pions and nucleons that…

High Energy Physics - Phenomenology · Physics 2009-10-22 Malcolm N. Butler , Martin J. Savage

Nucleon weak matrix elements can be extracted from nucleon correlation functions with lattice QCD simulations. The signal-to-noise ratio prohibits the analysis at large source-sink separations and as a consequence, excited state…

High Energy Physics - Lattice · Physics 2024-06-03 Lorenzo Barca , Gunnar Bali , Sara Collins

In this work we present the isovector flavor combination for the nucleon tensor charge extracted from lattice QCD simulations using overlap fermions on $N_f=2+1$ domain-wall configurations. The pion mass dependence is studied using six…

High Energy Physics - Lattice · Physics 2020-05-13 Derek Horkel , Yujiang Bi , Martha Constantinou , Terrence Draper , Jian Liang , Keh-Fei Liu , Zhaofeng Liu , Yi-Bo Yang

It is shown that the strong volume-dependence of the axial charge of the nucleon seen in lattice QCD calculations can be understood quantitatively in terms of the pion-induced interactions between neighbouring nucleons. The associated wave…

High Energy Physics - Lattice · Physics 2012-05-09 N. L. Hall , A. W. Thomas , R. D. Young , J. M. Zanotti

Leading-order electromagnetic loop corrections to the one-pion-exchange potential are computed within the framework of chiral perturbation theory. These corrections generate an effective nucleon-nucleon potential, $V_{\pi \gamma}$, which…

Nuclear Theory · Physics 2008-11-26 U. van Kolck , M. C. M. Rentmeester , J. L. Friar , T. Goldman , J. J. de Swart

We report nucleon mass, isovector vector and axial-vector charges, and tensor and scalar couplings, calculated using two recent 2+1-flavor dynamical domain-wall fermions lattice-QCD ensembles generated jointly by the RIKEN-BNL-Columbia and…

High Energy Physics - Lattice · Physics 2020-02-19 Michael Abramczyk , Thomas Blum , Taku Izubuchi , Chulwoo Jung , Meifeng Lin , Andrew Lytle , Shigemi Ohta , Eigo Shintani

We study the pion-mass dependence of the two-pion channel in the hadronic-vacuum-polarization (HVP) contribution to the anomalous magnetic moment of the muon $a_\mu^\text{HVP}$, by using an Omn\`es representation for the pion vector form…

High Energy Physics - Phenomenology · Physics 2022-01-07 Gilberto Colangelo , Martin Hoferichter , Bastian Kubis , Malwin Niehus , Jacobo Ruiz de Elvira

In the scaling regime, amplitudes for backward virtual Compton scattering and hadron annihilation into two photons depend on structure functions that describe the hadron-photon transition at the partonic level. We construct simple…

High Energy Physics - Phenomenology · Physics 2009-11-11 B. C. Tiburzi

We present a relativistic formulation of pion loop corrections to the coupling of photons with nucleons on the light-front. Vertex and wave function renormalization constants are computed to lowest order in the pion field, including their…

High Energy Physics - Phenomenology · Physics 2015-06-16 Chueng-Ryong Ji , W. Melnitchouk , A. W. Thomas

We analyze the CP-violating electric dipole form factor of the nucleon in the framework of covariant baryon chiral perturbation theory. We give a new upper bound on the vacuum angle, |\theta_0| \lesssim 2.5 \cdot 10^{-10}. The quark mass…

High Energy Physics - Phenomenology · Physics 2010-05-07 K. Ottnad , B. Kubis , U. -G. Meißner , F. -K. Guo

We discuss the question in the title employing manifestly covariant Baryon Chiral Perturbation Theory and recent high-statistics lattice results published in [1].

High Energy Physics - Lattice · Physics 2014-12-01 Peter C. Bruns , Ludwig Greil , Rudolf Rödl , Andreas Schäfer

An analysis is presented of the ground state baryon's (N and \Delta) masses and axial couplings in the combined 1/Nc and chiral expansions. Renormalization and alternative power counting schemes are discussed to one loop (NNLO). An…

High Energy Physics - Phenomenology · Physics 2012-09-04 A. Calle Cordon , J. L. Goity

We calculate the nucleon and the delta mass to fourth order in a covariant formulation of the small scale expansion. We analyze lattice data from the MILC collaboration and demonstrate that the available lattice data combined with our…

High Energy Physics - Lattice · Physics 2007-05-23 Véronique Bernard , Thomas R. Hemmert , Ulf-G. Meißner

A quantitative understanding of isospin violation is an increasingly important ingredient for the extraction of the nucleon's strange vector form factors from experimental data. We calculate the isospin violating electric and magnetic form…

Nuclear Theory · Physics 2008-11-26 Bastian Kubis , Randy Lewis

We consider the axial-vector together with its induced pseudo-scalar form factor of the nucleon as computed from the chiral Lagrangian with nucleon and isobar degrees of freedom. The form factors are evaluated at the one-loop level, where…

High Energy Physics - Phenomenology · Physics 2024-04-05 Felix Hermsen , Tobias Isken , David Thoma , Matthias F. M. Lutz

We investigate the chiral extrapolation of the lattice data for the light-heavy meson hyperfine splittings D^*-D and B^*-B to the physical region for the light quark mass. The chiral loop corrections providing non-analytic behavior in m_\pi…

High Energy Physics - Lattice · Physics 2010-02-17 X. -H. Guo , P. C. Tandy , A. W. Thomas

Within the framework of two-flavor covariant baryon chiral perturbation theory we have expressed the Chernyak-Zhitnitsky, Ioffe and Dosch currents in terms of chiral fields to provide leading one-loop extrapolation formulae for the leading…

High Energy Physics - Phenomenology · Physics 2015-05-28 Philipp Wein , Peter C. Bruns , Thomas R. Hemmert , Andreas Schäfer

Multi-particle states with additional pions are expected to be a non-negligible source of the excited-state contamination in lattice simulations at the physical point. It is shown that baryon chiral perturbation theory (ChPT) can be…

High Energy Physics - Lattice · Physics 2018-04-18 Oliver Bar

We present isovector nucleon observables: the axial, tensor, and scalar charges and the Dirac radius. Using the BMW clover-improved Wilson action and pion masses as low as 149 MeV, we achieve good control over chiral extrapolation to the…

High Energy Physics - Lattice · Physics 2013-01-11 Jeremy Green , Michael Engelhardt , Stefan Krieg , John Negele , Andrew Pochinsky , Sergey Syritsyn
‹ Prev 1 4 5 6 7 8 10 Next ›