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Related papers: Low--Energy Theorems for Weak Pion Production

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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

Some open topics in the field of low energy photon-nucleon interactions are discussed--which in my opinion are of interest both for obtaining new information on nucleon structure as well as for precision tests of our theoretical…

Nuclear Theory · Physics 2007-05-23 Thomas R. Hemmert

The charge changing weak production of Delta in nucleons and nuclei is studied. The reactions e^{-} p -> Delta^{0} \nu_{e} and e^{+} p -> Delta^{++} \bar{\nu}_{e} are considered as a possible source of information about the weak N-Delta…

Nuclear Theory · Physics 2011-02-09 L. Alvarez-Ruso , E. Oset , S. K. Singh , M. J. Vicente Vacas

We present a microscopic model for neutrino induced one-pion production off the nucleon and its implementation for the purpose of calculating coherent pion production in nuclei. We further criticize the use of the Rein--Sehgal model for…

High Energy Physics - Phenomenology · Physics 2009-12-07 J. E. Amaro , E. Hernández , J. Nieves , M. Valverde , M. J. Vicente-Vacas

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 2009-08-25 T. Huang , X. G. Wu , X. H. Wu

The leading-particle effect and the factorization property of the scattering amplitude in the impact parameter space are used to study semiclassical production of pions in the central region. The mechanism is related to the isospin-uniform…

High Energy Physics - Phenomenology · Physics 2011-04-15 M. Martinis , V. Mikuta-Martinis , J. Črnugelj

A large set of cross sections for semi-inclusive electroproduction of charged pions ($\pi^\pm$) from both proton and deuteron targets was measured. The data are in the deep-inelastic scattering region with invariant mass squared $W^2$ > 4…

The electric dipole form factor of the nucleon stemming from the QCD $\bar{\theta}$ term is calculated in chiral perturbation theory in leading order. To this order, the form factor originates from the pion cloud. Its momentum-dependence is…

Nuclear Theory · Physics 2009-11-11 W. H. Hockings , U. van Kolck

Following the Gauge Theory Bootstrap method proposed in our previous work [arXiv:2309.12402], we compute pion scattering phase shifts for all partial waves with angular momentum $\ell\le 3$ up to 2 GeV and calculate the low energy $\chi$PT…

High Energy Physics - Theory · Physics 2025-08-11 Yifei He , Martin Kruczenski

We consider the cross section of the deep inelastic pion electroproduction on a proton target at threshold for Q^2 in the region 5-10 GeV^2. The corresponding amplitudes are described in terms of two form factors which we calculate using…

High Energy Physics - Phenomenology · Physics 2008-11-26 V. M. Braun , D. Yu. Ivanov , A. Lenz , A. Peters

The longest-range part of the nuclear force due to the one-pion exchange governs the energy dependence of the scattering amplitude in the near-threshold region and imposes correlations between the coefficients in the effective range…

Nuclear Theory · Physics 2015-07-15 V. Baru , E. Epelbaum , A. A. Filin , J. Gegelia

A lattice determination of the form factor and decay constants for the semileptonic decay of heavy pseudoscalar (PS) mesons at zero recoil is presented from which the soft pion relation is satisfied. Chiral extrapolation of the form factor…

High Energy Physics - Lattice · Physics 2015-06-25 UKQCD Collaboration , K. C. Bowler , C. M. Maynard , L. Lellouch , J. Nieves , D. G. Richards , L. Del Debbio , J. M. Flynn , V. I. Lesk

The quark-level linear sigma model is employed to compute a variety of electromagnetic and weak observables of light mesons, including pion and kaon form factors and charge radii, charged-pion polarizabilities, semileptonic weak $K_{\ell3}$…

High Energy Physics - Phenomenology · Physics 2008-11-26 Michael D. Scadron , Frieder Kleefeld , George Rupp , Eef van Beveren

Single pion production in neutrino-nucleon scattering is discussed. The neutrino energies characteristic for T2K project are considered. Two new parameterizations of $C_5^A$ axial form factor are proposed. Both of them are obtained in…

High Energy Physics - Phenomenology · Physics 2008-10-08 Krzysztof M. Graczyk

We provide a precise calculation for the contribution of hard near threshold pion electro production to all nucleon structure functions. This framework will allow us to split the required nucleon to pion nucleon transition probability…

High Energy Physics - Phenomenology · Physics 2011-11-04 Thorsten Sachs

Near threshold neutral pion electroproduction on the deuteron is studied in the framework of baryon chiral perturbation theory at next-to-leading order in the chiral expansion. We develop the multipole decomposition for pion production off…

Nuclear Theory · Physics 2009-11-07 H. Krebs , V. Bernard , Ulf-G. Meißner

The electromagnetic form factor of the pion is calculated in a pseudoscalar field theoretical model which constituent quarks. We extract the form factor using the "+" component of the electromagnetic current in the light-cone formalism. For…

High Energy Physics - Phenomenology · Physics 2009-10-30 J. P. B. C. de Melo , H. W. L. Naus , T. Frederico

The study of exclusive $\pi^{\pm}$ electroproduction on the nucleon, including separation of the various structure functions, is of interest for a number of reasons. The ratio $R_L=\sigma_L^{\pi^-}/\sigma_L^{\pi^+}$ is sensitive to…

We investigate the pion scalar form factor in the Meiman-Okubo framework, implementing the phase below the inelastic $K\bar K$ threshold, where it is known from the $\pi\pi$ scalar isoscalar phase shift $\delta_0^0$ by Watson theorem.…

High Energy Physics - Phenomenology · Physics 2018-09-19 Irinel Caprini

We have investigated exclusive photoproduction of light vector mesons ($\omega$, $\rho$ and $\phi$) on the nucleon at low energies. In order to explore the questions concerning the so-called missing nucleon resonances, we first establish…

Nuclear Theory · Physics 2007-05-23 Yongseok Oh , Alexander I. Titov , T. -S. Harry Lee