English
Related papers

Related papers: Meson loop effects on the pion electromagnetic for…

200 papers

The first three coefficients of the Taylor's series expansion of the vector pion form factor as a function of the momentum transfer are evaluated using experimental data on the pion form factor and the P-wave pi pi phase shifts. The real…

High Energy Physics - Phenomenology · Physics 2007-05-23 Tran N. Truong

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 s^(1/2) ~ 1.2 GeV and allows a model-independent…

High Energy Physics - Phenomenology · Physics 2009-11-07 A. Pich , J. Portoles

We study the electromagnetic structure of the pion in terms of the quantum cromodynamic~(QCD) model on the Breit-frame. We calculated the observables, such as the electromagnetic form factor. The priori to have a calculation covariant need…

High Energy Physics - Phenomenology · Physics 2016-05-17 Clayton Santos Mello , J. P. B. C. de Melo , T. Frederico

We study the pion form factor in a broad range of spacelike momentum transfers within the local-duality version of QCD sum rules. We make use of the recently calculated two-loop double spectral density of the $<AVA>$ correlator including…

High Energy Physics - Phenomenology · Physics 2008-11-26 Victor Braguta , Wolfgang Lucha , Dmitri Melikhov

A microscopic model of the electromagnetic form factor of the nucleon is developed in a hadronic framework, including pions, nucleons and the Delta-resonance explicitly. The space like on-shell form factors are reproduced and predictions…

Nuclear Theory · Physics 2009-09-25 H. C. Doenges , M. Schaefer , U. Mosel

Medium modification of pion form factor has been evaluated in asymmetric nuclear matter. It is shown that both the shape and the pole position of the pion form factor in dense asymmetric nuclear matter is different from its vacuum…

Nuclear Theory · Physics 2008-11-26 Pradip Roy , Abhee K. Dutt-Mazumder , Sourav Sarkar , Jan-e Alam

We extend a recent analysis of the pion electromagnetic form factor constrained by the conformal symmetry to explore the time-like region. We show explicitly that the time-like form factor obtained by the analytic continuation of the…

High Energy Physics - Phenomenology · Physics 2008-11-26 Ho-Meoyng Choi , Chueng-Ryong Ji

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 reanalyze the world data on the electromagnetic form factors of the nucleon. The calculations are performed in the framework of an algebraic model of the nucleon combined with vector meson dominance.

Nuclear Theory · Physics 2017-11-03 R. Bijker , A. Leviatan

We analyze the electromagnetic pion and kaon form factor by including radiative and higher-twist effects within the framework of resummed pQCD in the space-like region. We focus on the transition from the perturbative to non-perturbative…

High Energy Physics - Phenomenology · Physics 2009-03-02 Udit Raha , Andreas Aste

The isospin symmetry breakings of q{\bar q} are investigated in the QCD sum rule method. The electromagnetic effects are evaluated following the procedure requiring that the electromagnetic effects for charged meson be gauge invariant. We…

High Energy Physics - Phenomenology · Physics 2009-10-30 Shi-lin Zhu , Zhenping Li

We review our studies of spectator-induced electromagnetic (EM) effects on the emission of charged mesons in the final state of ultrarelativistic heavy ion collisions. We argue that these effects offer sensitivity to the distance $d_E$…

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

The inclusion of the $\rho-\omega$ mixing effect is essential for a precise description of the pion electromagnetic form factor in the $e^+e^- \rightarrow \pi^+\pi^-$ process, which quantifies the two-pion contribution to the anomalous…

High Energy Physics - Phenomenology · Physics 2023-08-23 Yun-Hua Chen , Meng-Ge Qin

We present a lattice calculation of the vector form factor of the pion for two flavours of non-perturbatively O(a) improved Wilson fermions. For the measurements we utilise the CLS ensembles which include various lattice spacings and pion…

High Energy Physics - Lattice · Physics 2011-09-02 Bastian B. Brandt , Andreas Juttner , Hartmut Wittig

We discuss various aspects of vector meson production, first analysing the interplay between perturbative and nonperturbative aspects of the QCD calculation. Using a general method adapted to incorporate both perturbative and nonpertubative…

High Energy Physics - Phenomenology · Physics 2008-11-26 H. G. Dosch , E. Ferreira

We investigate the valence quark distribution function of the pion $v^{\pi}(x,Q^2)$ in the framework of the chiral constituent quark model and evaluate the meson cloud effects on $v^{\pi}(x,Q^2)$. We explicitly demonstrate how the meson…

High Energy Physics - Phenomenology · Physics 2016-12-14 Akira Watanabe , Chung Wen Kao , Katsuhiko Suzuki

We present the first calculation of the pion electromagnetic form factor at physical light quark masses. This form factor parameterises the deviations from the behaviour of a point-like particle when a photon hits the pion. These deviations…

High Energy Physics - Lattice · Physics 2017-10-23 Jonna Koponen , Francis Bursa , Christine T. H. Davies , Rachel J. Dowdall , G. Peter Lepage

We have applied the light-front formalism to calculate the electromagnetic form factors for the pion and the kaon from two models at low and high energies in order to explore the differences between such models. We have also compared the…

High Energy Physics - Phenomenology · Physics 2014-11-20 O. A. T. Dias , V. S. Filho , J. P. B. C. de Melo

We comment on the results of a complete leading-twist next-to-leading order QCD analysis of the spacelike pion electromagnetic form factor at large-momentum transfer Q. For the asymptotic distribution amplitude, we have examined the…

High Energy Physics - Phenomenology · Physics 2007-05-23 B. Melic , B. Nizic , K. Passek