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Related papers: Twisted mass QCD for the pion electromagnetic form…

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We present an ongoing project aimed at determining the thermodynamic Equation of State (EoS) of quark--gluon matter from lattice QCD with two generations of dynamical quarks. We employ the Wilson twisted mass implementation for the…

High Energy Physics - Lattice · Physics 2016-02-17 F. Burger , E. -M. Ilgenfritz , M. P. Lombardo , M. Muller-Preussker , A. Trunin

In this report we present the status of the Mainz group's lattice QCD calculation of the pion transition form factor, which describes the interaction of an on-shell pion with two off-shell photons. This form factor is the main ingredient in…

High Energy Physics - Lattice · Physics 2023-11-14 Jonna Koponen , Antoine Gérardin , Harvey B. Meyer , Konstantin Ottnad , Georg von Hippel

The electromagnetic form factor of the pion in the space-like region, and at finite temperature, $F_{\pi}(Q^{2},T)$, is obtained from a QCD Finite Energy Sum Rule. The form factor decreases with increasing T, and vanishes at some critical…

High Energy Physics - Phenomenology · Physics 2009-10-28 C. A. Dominguez , M. Loewe , J. S. Rozowsky

We present a preliminary lattice calculation of the $D \to \pi$ and $D \to K$ tensor form factors $f_T(q^2)$ as a function of the squared 4-momentum transfer $q^2$. ETMC recently computed the vector and scalar form factors $f_+(q^2)$ and…

High Energy Physics - Lattice · Physics 2018-04-18 Vittorio Lubicz , Lorenzo Riggio , Giorgio Salerno , Silvano Simula , Cecilia Tarantino

This review contains an overview over recent results for the electromagnetic iso-vector form factor of the pion obtained in lattice QCD with dynamical fermions. Particular attention is given to the extrapolation to the physical point and an…

High Energy Physics - Lattice · Physics 2014-02-14 Bastian B. Brandt

It is known that the trace anomaly in the QCD energy-momentum tensor $T^{\mu \nu}$ can be attributed to the anomalies for each of the gauge-invariant quark part and gluon part of $T^{\mu \nu}$, and their explicit three-loop formulas have…

High Energy Physics - Phenomenology · Physics 2023-03-22 Kazuhiro Tanaka

The exact decomposition of the proton spin has been a much debated topic, on the experimental as well as the theoretical side. In this talk we would like to report on recent non-perturbative results and ongoing efforts to explore the proton…

We use a version of the instant-form relativistic quantum mechanics of composite systems to obtain the gravitational form factors of the pion in a common approach to its electroweak and gravitational properties. In the preceding work…

High Energy Physics - Phenomenology · Physics 2022-09-16 A. F. Krutov , V. E. Troitsky

The $\gamma^\ast \gamma \to \pi^0$ transition form factor, $G(Q^2)$, is computed on the entire domain of spacelike momenta using a continuum approach to the two valence-body bound-state problem in relativistic quantum field theory: the…

We compute the electromagnetic form factors of the proton and neutron using lattice QCD. We employ $N_\mathrm{f}$=2+1+1 twisted mass clover-improved fermions with quark masses tuned to their physical values. Three ensembles with lattice…

High Energy Physics - Lattice · Physics 2025-07-29 Constantia Alexandrou , Simone Bacchio , Giannis Koutsou , Bhavna Prasad , Gregoris Spanoudes

The hadron mass can be obtained through the calculation of the trace of the energy-momentum tensor in the hadron which includes the trace anomaly and sigma terms. The anomaly due to conformal symmetry breaking is believed to be an important…

High Energy Physics - Lattice · Physics 2024-05-10 Bigeng Wang , Fangcheng He , Gen Wang , Terrence Draper , Jian Liang , Keh-Fei Liu , Yi-Bo Yang

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

Lattice formulations of QCD with Wilson fermions and a chirally twisted quark mass matrix provide an attractive framework for non-perturbative numerical studies. Owing to reparameterization invariance, the limiting continuum theory is just…

High Energy Physics - Lattice · Physics 2009-11-07 R. Frezzotti

The pion form factors of the QCD energy-momentum tensor (EMT) are studied in the instanton liquid model (ILM) of the QCD vacuum. In this approach the breaking of conformal symmetry is encoded in the form of stronger-than-Poisson…

High Energy Physics - Phenomenology · Physics 2024-10-16 Wei-Yang Liu , Edward Shuryak , Christian Weiss , Ismail Zahed

We describe the present status of the pion distribution amplitude (DA) as it originated from several sources: (i) a nonperturbative approach, based on QCD sum rules with nonlocal condensates, (ii) an O(\alpha_s) QCD analysis of the CLEO…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. P. Bakulev

We compute the matrix elements of the electromagnetic (EM) operator (\bar{s} F{\mu \nu} \sigma{\mu \nu} d) between kaon and pion states, using lattice QCD with maximally twisted-mass fermions and two flavors of dynamical quarks (Nf = 2).…

High Energy Physics - Lattice · Physics 2011-10-27 I. Baum , V. Lubicz , G. Martinelli , L. Orifici , S. Simula

The gravitational form factors (GFFs) of pions are calculated from a top-down holographic quantum chromodynamics (QCD) approach with momentum transfer dependence for the first time. It is important because the GFFs of hadrons have…

High Energy Physics - Phenomenology · Physics 2024-11-13 Daisuke Fujii , Akihiro Iwanaka , Mitsuru Tanaka

Accessing hadronic form factors at large momentum transfers has traditionally presented a challenge for lattice QCD simulations. Here we demonstrate how a novel implementation of the Feynman-Hellmann method can be employed to calculate…

Non-leading contribution to the pion electromagnetic form factor which comes from the pion twist-3 wave function is analyzed in the modified hard scattering approach (MHSA) proposed by Li and Sterman. This contribution is enhanced…

High Energy Physics - Phenomenology · Physics 2009-08-25 Fu-Guang Cao , Yuan-Ben Dai , Chao-Shang Huang

Lattice QCD can provide a direct determination of meson electromagnetic form factors, making predictions for upcoming experiments at Jefferson Lab. The form factors are a reflection of the bound-state nature of the meson and so these…

High Energy Physics - Lattice · Physics 2019-02-12 C. T. H. Davies , J. Koponen , G. P. Lepage , A. T. Lytle , A. C. Zimermmane-Santos