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Related papers: Pion electroproduction in a nonrelativistic theory

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These lectures give an introduction to baryon chiral perturbation theory. I show in detail how to construct the chiral effective pion-nucleon Lagrangian in the one loop approximation. Particular emphasis is put on the physics related to…

High Energy Physics - Phenomenology · Physics 2007-05-23 Ulf-G. Meißner

Methods are set forth for determining the hadron electromagnetic structure in the sub-$N\bar{N}$-threshold timelike region of the virtual-photon ``mass'' and for investigating the nucleon weak structure in the spacelike region from…

Nuclear Theory · Physics 2009-11-10 Yu. S. Surovtsev , T. D. Blokhintseva , P. Bydzovsky , M. Nagy

Single pion production off nucleons is studied in the framework of relativistic baryon chiral perturbation theory at tree level with the inclusion of the terms from the dimension two effective pion-nucleon Lagrangian. The five appearing…

High Energy Physics - Phenomenology · Physics 2009-10-30 V. Bernard , N. Kaiser , Ulf-G. Meißner

We present novel low--energy theorems for the P--wave multipoles $2M_{1+} + M_{1-}$, $M_{1+} -M_{1-}$, $E_{1+}$ and $L_{1\pm}$ for neutral pion electroproduction off protons. These should be very useful for the analysis of existing or…

High Energy Physics - Phenomenology · Physics 2009-10-28 V. Bernard , N. Kaiser , Ulf-G. Meißner

We present a calculation of pion photo- and electroproduction in manifestly Lorentz-invariant baryon chiral perturbation theory up to and including order q^4. We fix the low-energy constants by fitting experimental data in all available…

Nuclear Theory · Physics 2015-06-18 Lothar Tiator , Stefan Scherer , Marius Hilt

We have investigated the neutrino induced coherent pion production reaction at low and intermediate energies including pion, nucleon and Delta(1232) resonance. Medium effects in the production mechanism and the distortion of the pion wave…

Nuclear Theory · Physics 2007-09-06 L. Alvarez-Ruso , L. S. Geng , S. Hirenzaki , M. J. Vicente Vacas

In this review we present the recent advances for calculations of the reactions $NN\to NN\pi$ using chiral effective field theory. Discussed are the next-to-next-to leading order loop contributions with nucleon and Delta-isobar for near…

Nuclear Theory · Physics 2015-06-17 Vadim Baru , Christoph Hanhart , Fred Myhrer

I review the interesting tale of the electric dipole amplitude in neutral pion photoproduction and the resulting consequences. I also discuss why there is new life related to P--wave multipoles. Electroproduction is briefly touched upon.

High Energy Physics - Phenomenology · Physics 2007-05-23 Ulf-G. Meißner

The invariant amplitudes for pion electroproduction on the nucleon are evaluated by dispersion relations at constant t with MAID as input for the imaginary parts of these amplitudes. In the threshold region these amplitudes are confronted…

High Energy Physics - Phenomenology · Physics 2008-11-26 B. Pasquini , D. Drechsel , L. Tiator

We study the reaction of pion photoproduction on the nucleon in the framework of chiral perturbation theory with explicit $\Delta(1232)$ degrees of freedom. In the covariant approach, we give results up to order $\epsilon^3$ in the small…

Nuclear Theory · Physics 2021-08-04 N. Rijneveen , A. M. Gasparyan , H. Krebs , E. Epelbaum

The neutral pion electroproduction on the proton is considered in the framework phenomenological model based on the PCAC, current algebra with hard pions and chiral symmetry breaking interaction. The s- wave differential cross-section of…

High Energy Physics - Phenomenology · Physics 2007-05-23 Alexander Tabachenko

We derive an analytic expression for the Kroll-Ruderman amplitude up to the order 1/N_C for general Skyrme-type models of the nucleon. Due to the degeneracy of intermediate N- and Delta-states we find deviations from the standard low-energy…

High Energy Physics - Phenomenology · Physics 2009-10-22 B. Schwesinger , H. Walliser

We present a theory of neutrino interactions with nuclei aimed at the description of the partial cross-sections, namely quasi-elastic and multi-nucleon emission, coherent and incoherent single pion production. For this purpose, we use the…

Nuclear Theory · Physics 2013-03-21 M. Martini , M. Ericson , G. Chanfray , J. Marteau

A calculation of the pion-production operator up to next-to-next-to-leading order for s-wave pions is performed within chiral effective field theory. In the previous study [Phys. Rev. C 85, 054001 (2012)] we discussed the contribution of…

Nuclear Theory · Physics 2013-12-16 A. A. Filin , V. Baru , E. Epelbaum , C. Hanhart , H. Krebs , F. Myhrer

The S-matrix approach is used to calculate charged as well as neutral pion production reactions from NN scattering, with the same set of underlying processes and interactions. The chiral perturbation theory piN scattering amplitude is used.…

Nuclear Theory · Physics 2008-11-26 V. Malafaia , M. T. Pena , Ch. Elster , J. Adam

Weak pion production off the nucleon at low energies has been systematically investigated in manifestly relativistic baryon chiral perturbation theory with explicit inclusion of the $\Delta$(1232) resonance. Most of the involved low-energy…

High Energy Physics - Phenomenology · Physics 2018-10-10 De-Liang Yao , Luis Alvarez-Ruso , Astrid N. Hiller Blin , M. J. Vicente Vacas

QCD-based scaling arguments predict the predominance of longitudinal over transverse electroproduction of pions by terms $\propto Q^2$. However, data from JLAB, Cornell and DESY, covering a wide kinematical range $1 < Q^2 < 11\, {\rm…

Nuclear Theory · Physics 2015-05-30 Murat Kaskulov , Ulrich Mosel

Understanding pion production in nucleon-nucleon collisions near threshold has been a challenge for the last decades. In particular, the reaction pp -> pppi0 is highly sensitive to short-range mechanisms, because isospin conservation…

Nuclear Theory · Physics 2009-09-29 Veronica Malafaia

We analyze the $\gamma N\to\pi N$ process in the negative parity channel with Hamiltonian effective filed theory which is successful in studying the nucleon resonances associated with the meson-nucleon scattering and lattice QCD…

High Energy Physics - Phenomenology · Physics 2022-06-28 Dan Guo , Zhan-Wei Liu

We present a detailed quark-model study of pion photoproduction within the effective Lagrangian approach. Cross sections and single-polarization observables are investigated for the four charge channels, $\gamma p\to \pi^+ n$, $\gamma n\to…

Nuclear Theory · Physics 2009-11-07 Q. Zhao , J. S. Al-Khalili , Z. -P. Li , R. L. Workman