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Related papers: Pion and Rho Structure Functions from Lattice QCD

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We construct several classes of hadronic matrix elements and relate them to the low-energy constants in Chiral Perturbation Theory that describe the electromagnetic effects in the semileptonic beta decay of the pion and the kaon. We propose…

High Energy Physics - Lattice · Physics 2020-10-29 Chien-Yeah Seng , Xu Feng , Mikhail Gorchtein , Lu-Chang Jin , Ulf-G. Meißner

Quantum Chromodynamics on a lattice with Wilson fermions and a chirally twisted mass term for two degenerate quark flavours is considered in the framework of chiral perturbation theory. The pion masses and decay constants are calculated in…

High Energy Physics - Lattice · Physics 2010-12-23 Gernot Münster , Christian Schmidt , Enno E. Scholz

The pion masses and the pion decay constant are calculated to 1-loop order in twisted mass Wilson chiral perturbation theory, assuming a large pion mass splitting and tuning to maximal twist. Taking the large mass splitting at leading order…

High Energy Physics - Lattice · Physics 2010-12-13 Oliver Bar

We present the first-ever lattice computation of pi pi-scattering in the I=1 channel with Nf=2 dynamical quark flavours obtained including an ensemble with physical value of the pion mass. Employing a global fit to data at three values of…

The charge form factor of the pion is calculated in lattice QCD. The non-perturbatively improved Sheikholeslami-Wohlert action is used together with the $\mathcal{O}(a)$ improved vector current. Other choices for the current are examined.…

High Energy Physics - Lattice · Physics 2009-11-10 J. van der Heide , J. Koch , E. Laermann

We extend the epsilon-expansion of continuum chiral perturbation theory to nonzero lattice spacing in the framework of Wilson Chiral Perturbation Theory. We distinguish various regimes by defining the relative power counting of the quark…

High Energy Physics - Lattice · Physics 2010-11-05 Oliver Bar , Silvia Necco , Stefan Schaefer

The pion structure function is investigated in a simple model, where pion and constituent quark fields are coupled through the simplest pseudoscalar coupling. The imaginary part of the forward gamma* pi-> gamma* pi scattering amplitude is…

High Energy Physics - Phenomenology · Physics 2009-11-07 F. Bissey , J. R. Cudell , J. Cugnon , M. Jaminon , J. P. Lansberg , P. Stassart

We present first results on the $\rho$ resonance parameters obtained with $N_f=2+1+1$ Wilson twisted mass fermions at maximal twist. Using ensembles of the ETM collaboration, we provide results for two values of the lattice spacing and a…

High Energy Physics - Lattice · Physics 2015-12-02 C. Helmes , C. Jost , B. Knippschild , L. Liu , C. Urbach , M. Werner , Z. Wang

We present a brief review of results of chiral quark models for soft matrix elements in the pion state, appearing in high-energy processes as well as accessible in present and future lattice studies. A particular attention is paid to the…

High Energy Physics - Phenomenology · Physics 2021-02-03 Wojciech Broniowski , Enrique Ruiz Arriola

We present a lattice calculation of the electromagnetic form factor of the pion obtained using the tree-level Symanzik improved gauge action with two flavors of dynamical twisted Wilson quarks. The simulated pion masses range approximately…

High Energy Physics - Lattice · Physics 2009-11-06 R. Frezzotti , V. Lubicz , S. Simula

We study light meson properties in a magnetic field, focusing on a charged pion and a charged and polarized rho meson, in quenched lattice QCD. The gauge-invariant density-density correlators are calculated to investigate the deformation…

High Energy Physics - Lattice · Physics 2019-04-30 Koichi Hattori , Arata Yamamoto

We report on numerical lattice QCD calculations of some of the low moments of the nucleon structure functions. The calculations are carried out with gauge configurations generated by the RBC and UKQCD collaborations with (2+1)-flavors of…

High Energy Physics - Lattice · Physics 2014-11-20 Yasumichi Aoki , Tom Blum , Huey-Wen Lin , Shigemi Ohta , Shoichi Sasaki , Robert Tweedie , Takeshi Yamazaki , James Zanotti

This is a review of hadron structure physics from lattice QCD. Throughout this report, we place emphasis on the contribution of lattice results to our understanding of a number of fundamental physics questions related to, e.g., the origin…

High Energy Physics - Lattice · Physics 2010-04-29 Ph. Hägler

The variational method allows one to study the mixing of interpolators with different chiral transformation properties in the nonperturbatively determined physical state. It is then possible to define and calculate in a gauge-invariant…

High Energy Physics - Lattice · Physics 2010-10-28 L. Ya. Glozman , C. B. Lang , M. Limmer

We present results for the nucleon structure functions and form factors obtained from 2+1 flavor lattice QCD with physical light quark masses ($m_{\pi}=135$ MeV) in a large spatial extent of about 10 fm. Our calculations are performed with…

High Energy Physics - Lattice · Physics 2022-01-03 Ryutaro Tsuji , Yasumichi Aoki , Ken-Ichi Ishikawa , Yoshinobu Kuramashi , Shoichi Sasaki , Eigo Shintani , Takeshi Yamazaki

We present results for Monte Carlo calculations of the electromagnetic vector and scalar form factors of the pion in a quenched simulation. We work at a lattice spacing of 0.15 fm and use two lattice volumes up to a spatial size of 2.4 fm.…

High Energy Physics - Lattice · Physics 2007-05-23 Stefano Capitani , Christof Gattringer , C. B. Lang

We present an investigation of pion structure based on ETMC $N_f=2$ and $N_f=2+1+1$ twisted mass configurations at maximal twist. We compute the first moment of the quark momentum fraction of the pion, $\langle x \rangle$ and the…

High Energy Physics - Lattice · Physics 2016-12-06 Bartosz Kostrzewa , Maximilian Oehm , Francesco Sanfilippo , Silvano Simula , Carsten Urbach

We report the first Lattice QCD calculation using the almost physical pion mass mpi=149 MeV that agrees with experiment for four fundamental isovector observables characterizing the gross structure of the nucleon: the Dirac and Pauli radii,…

High Energy Physics - Lattice · Physics 2014-08-04 J. R. Green , M. Engelhardt , S. Krieg , J. W. Negele , A. V. Pochinsky , S. N. Syritsyn

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 present a lattice QCD calculation of the parameters of the $\rho$ meson decay. The study is carried out on spatially asymmetric boxes using nHYP-smeared clover fermions with two mass-degenerate quark flavors. Our calculations are carried…

High Energy Physics - Lattice · Physics 2013-05-30 Craig Pelissier , Andrei Alexandru