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Related papers: Pion form factor with chirally improved fermions

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We present a high-statistics calculation of nucleon electromagnetic form factors in $N_f=2+1$ lattice QCD using domain wall quarks on fine lattices, to attain a new level of precision in systematic and statistical errors. Our calculations…

We provide a novel approach to calculate the gravitational form factor of pion under the ladder approximation of the Bethe-Salpeter equation, with contact interactions. Central to this approach is a symmetry-preserving treatment of the…

High Energy Physics - Phenomenology · Physics 2023-03-01 Zanbin Xing , Minghui Ding , Lei Chang

We report a first principle lattice calculation of the pion electric polarizability $\alpha_\pi$ at the physical pion mass. First, we derive the master formula, which relates the pion polarizabilities with the position space hadronic…

High Energy Physics - Lattice · Physics 2022-01-06 Xu Feng , Taku Izubuchi , Luchang Jin , Maarten Golterman

We calculate the possible scalar, vector, and tensor form factors (FFs) for pion and kaon in the light-cone quark model (LCQM). These FFs are calculated from the leading and sub-leading twist generalized parton distribution functions (GPDs)…

High Energy Physics - Phenomenology · Physics 2025-09-19 Satyajit Puhan , Harleen Dahiya

We analyse the pion electromagnetic, charged-current, and $\pi\gamma$ transition form factors at timelike momentum transfers $q$, $q^2=s\le 1.4$ GeV$^2$, using a dispersion approach. We discuss in detail the propagator matrix of the…

High Energy Physics - Phenomenology · Physics 2009-11-10 D. Melikhov , O. Nachtmann , V. Nikonov , T. Paulus

We compare overlap fermions, which are chirally invariant, and Wilson twisted mass fermions in the approach to the chiral limit. Our quenched simulations reveal that with both formulations of lattice fermions pion masses of O(250 MeV) can…

We study a model-independent parameterization of the vector pion form factor that arises from the constraints of analyticity and unitarity. Our description should be suitable up to sqrt(s) ~ 1.2 GeV and allows a model-independent…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. Pich , J. Portoles

A variety of strong and electroweak interaction properties of the pion and the light scalar sigma meson are computed in a relativistic quark model. Under the assumption that the resulting coupling of these mesons to the constituent quarks…

High Energy Physics - Phenomenology · Physics 2009-11-10 Amand Faessler , Th. Gutsche , M. A. Ivanov , V. E. Lyubovitskij , P. Wang

A calculation for the one-loop pion vector form-factor in Resonance Chiral Theory is provided in this talk. The amplitude is computed up to next-to-leading order in 1/Nc and, by means of high-energy constraints, we are able to produce a…

High Energy Physics - Phenomenology · Physics 2011-02-01 J. J. Sanz-Cillero

We report a recent lattice-QCD calculation of nucleon and pion electromagnetic form factors and nucleon axial form factors, with special emphasis on large $Q^2$. Conventional lattice form-factor calculations can only reach about 2.5…

High Energy Physics - Lattice · Physics 2015-03-19 Huey-Wen Lin , Saul D. Cohen

The H(e,e'pi+)n cross section was measured at four-momentum transfers of Q2=1.60 and 2.45 GeV2 at an invariant mass of the photon nucleon system of W=2.22 GeV. The charged pion form factor (F_pi) was extracted from the data by comparing the…

We analyze the pion transition form factor using dispersion theory. We calculate the singly-virtual form factor in the time-like region based on data for the $e^+e^-\to 3\pi$ cross section, generalizing previous studies on…

High Energy Physics - Phenomenology · Physics 2014-12-19 Martin Hoferichter , Bastian Kubis , Stefan Leupold , Franz Niecknig , Sebastian P. Schneider

We employ a dispersion relation that allows to recover the phase of the electromagnetic form factor of the pion from its absolute value above threshold. Compared to alternative approaches building on the phase, this approach builds on…

High Energy Physics - Phenomenology · Physics 2024-07-29 Enrique Ruiz Arriola , Pablo Sanchez-Puertas

By considering a one loop background field method for a nonperturbative one gluon exchange between quarks, leading electromagnetic form factors of pion couplings to constituent quarks are derived by means of from a large quark and gluon…

High Energy Physics - Phenomenology · Physics 2020-08-25 Fabio L. Braghin , Willian F. de Sousa

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

The charged pion form factor, Fpi(Q^2), is an important quantity which can be used to advance our knowledge of hadronic structure. However, the extraction of Fpi from data requires a model of the 1H(e,e'pi+)n reaction, and thus is…

The electromagnetic form factors of vector mesons are calculated in an explicitly Poincar\'e covariant formulation, based on the Dyson--Schwinger equations of QCD, that respects electromagnetic current conservation, and unambiguously…

Nuclear Theory · Physics 2008-11-26 M. S. Bhagwat , P. Maris

We present results of a calculation of the electromagnetic pion form factor within the framework of QCD Sum Rules with nonlocal condensates, using a perturbative spectral density which includes $O(\alpha_s)$ contributions.

High Energy Physics - Phenomenology · Physics 2014-11-18 Alexander P. Bakulev , A. V. Pimikov , N. G. Stefanis

We investigate the pion and kaon (pi^+, K^+, K^0) electromagnetic form factors in the space-like region: Q^2 ~< 1 GeV, based on the gauged low-energy effective chiral action from the instanton vacuum in the large N_c limit. Explicit flavor…

High Energy Physics - Phenomenology · Physics 2008-11-26 Seung-il Nam , Hyun-Chul Kim

We compute the Kl3 and pion form factors using partially twisted boundary conditions. The twists are chosen so that the Kl3 form factors are calculated directly at zero momentum transfer (q^2=0), removing the need for a q^2 interpolation,…

High Energy Physics - Lattice · Physics 2010-01-21 P. A. Boyle , J. M. Flynn , A. Jüttner , C. Kelly , H. Pedroso de Lima , C. M. Maynard , C. T. Sachrajda , J. M. Zanotti