English
Related papers

Related papers: Pion transverse charge density from $e^+$$e^-$ ann…

200 papers

Based on the light-cone (LC) framework and the $k_T$ factorization formalism, the transverse momentum effects and the different helicity components' contributions to the pion form factor $F_{\pi}(Q^2)$ are recalculated. In particular, the…

High Energy Physics - Phenomenology · Physics 2009-11-11 Xing-Gang Wu , Tao Huang

The light-front approach is applied to calculate the electromagnetic current for quark-antiquark bound states for the pion. The pion electromagnetic form factor is obtnaide from the "+" and "-" components of the electromagnetic current in…

High Energy Physics - Phenomenology · Physics 2007-05-23 J. P. B. C. de Melo

We explore the structure of the spin-1/2 flavor-octet baryons (hyperons) through their electromagnetic transverse densities. The transverse densities describe the distribution of charge and magnetization at fixed light-front time and enable…

High Energy Physics - Phenomenology · Physics 2018-02-05 Jose Manuel Alarcón , Astrid N. Hiller Blin , Manuel J. Vicente Vacas , Christian Weiss

A fit of the experimental data to the total cross section of the process $\gamma\gamma->\pi^+\pi^-$ in the energy region from threshold to 2500 MeV has been carried out using dispersion relations with subtractions for the invariant…

Nuclear Theory · Physics 2011-07-19 L. V. Fil'kov , V. L. Kashevarov

We present a dispersion theoretical analysis of the experimental data on the electromagnetic form factors of the nucleon covering both the space- and time-like regions. The nucleon form factors over the full range of momentum transfers and…

High Energy Physics - Phenomenology · Physics 2022-02-18 Yong-Hui Lin

Inspired by light-front holography, we compute the pion mass, charge radius, decay constant, electromagnetic form factor and electromagnetic transition form factor. To do so, we model the longitudinal quark dynamics using potentials due to…

High Energy Physics - Phenomenology · Physics 2025-01-03 Jeff Forshaw , Ruben Sandapen

A method is explained through which a pointwise accurate approximation to the pion's valence-quark distribution amplitude (PDA) may be obtained from a limited number of moments. In connection with the single nontrivial moment accessible in…

Nuclear Theory · Physics 2015-06-16 I. C. Cloët , L. Chang , C. D. Roberts , S. M. Schmidt , P. C. Tandy

We study in various chiral models the pion charge radius, $\pi_{e3}$ form factor ratio, $\pi^\circ \to \gamma \gamma$ amplitude, charge pion polarizabilities, $\gamma\gamma \to \pi^\circ \pi^\circ$ amplitude at low energies and the $\pi\pi$…

High Energy Physics - Phenomenology · Physics 2014-11-17 M. D. Scadron

We use a method to calculate the hadron's charge radius without model-dependent momentum extrapolations. The method does not require the additional quark propagator inversions on the twisted boundary conditions or the computation of the…

High Energy Physics - Lattice · Physics 2020-04-01 Xu Feng , Yang Fu , Lu-Chang Jin

Using our present knowledge on effective hadronic theories, short-distance QCD information, the $1/N_C$ expansion, analyticity and unitarity, we derive an expression for the pion form factor, in terms of $m_\pi, m_K, M_\rho$ and $f_\pi$.…

High Energy Physics - Phenomenology · Physics 2011-05-05 F. Guerrero , A. Pich

Correlation data from high-energy p-p collisions indicate substantial anticorrelation of like-sign pions and correlation of unlike-sign pions on rapidity and azimuth at small length scale suggesting approach to a 1D lattice structure during…

High Energy Physics - Phenomenology · Physics 2007-05-23 Thomas A. Trainor

The spectral function of the charged pion form factor was extracted from two data sets. The difference between the two sets is based on the presence or absence of the recent measurement of the $\pi^+ \pi^-$ production by CMD3. Although the…

High Energy Physics - Experiment · Physics 2026-03-16 Dimitrios Petrellis , Vladimir Sauli

We perform a nonperturbative lattice calculation of the complex phase and modulus of the pion form factor in the timelike momentum region using the finite-volume technique. We use two ensembles of 2+1-flavor overlap fermion at pion masses…

High Energy Physics - Lattice · Physics 2015-03-18 Xu Feng , Sinya Aoki , Shoji Hashimoto , Takashi Kaneko

We consider how to extract the pion form factors in the epsilon regime. Using the correlators with non-zero momenta and taking appropriate ratios of them, we eliminate the dominant finite volume effect from the zero-momentum pion mode. Our…

High Energy Physics - Lattice · Physics 2012-11-06 JLQCD Collaboration , H. Fukaya , S. Aoki , S. Hashimoto , T. Kaneko , H. Matsufuru , J. Noaki , T. Onogi , N. Yamada

Recent experimental pion polarizability data are reviewed and analyzed. Data on the radiative \pi^+ meson photoproduction on the proton at MAMI has been used to determine the difference of the electric and magnetic dipole polarizabilities…

High Energy Physics - Phenomenology · Physics 2007-05-23 L. V. Fil'kov , V. L. Kashevarov

A puzzling discrepancy exists between the values of the proton charge radius obtained using different experimental techniques: elastic electron-proton scattering and spectroscopy of electronic and muonic hydrogen. The proton radius is…

Nuclear Experiment · Physics 2022-03-07 Alexander V. Gramolin , Rebecca L. Russell

The leptonic decay of the charged pion in the presence of background magnetic fields is investigated using quenched Wilson fermions. It is demonstrated that the magnetic field opens up a new channel for this decay. The magnetic…

High Energy Physics - Lattice · Physics 2018-04-18 Gunnar S. Bali , Bastian B. Brandt , Gergely Endrodi , Benjamin Glaessle

We present a precise calculation of the pion form factor using overlap fermions on seven ensembles of 2+1-flavor domain-wall configurations with pion masses varying from 139 to 340 MeV. Taking advantage of the fast Fourier transform and…

High Energy Physics - Phenomenology · Physics 2021-10-13 Gen Wang , Jian Liang , Terrence Draper , Keh-Fei Liu , Yi-Bo Yang

We analyze a low-energy theorem of threshold pion electroproduction which allows one to determine the charge radius of the pion. We show that at the same order where the radius appears, pion loops induce a correction to the momentum…

Nuclear Theory · Physics 2009-11-06 Véronique Bernard , Norbert Kaiser , Ulf-G. Meißner

The nonperturbative, Dyson-Schwinger equation approach to solving QCD provides a straightforward, microscopic description of dynamical chiral symmetry breaking and confinement. It is an ideal tool for the study of pion observables. This is…

High Energy Physics - Phenomenology · Physics 2009-10-28 Craig D. Roberts