English
Related papers

Related papers: Pion-photon exchange nucleon-nucleon potentials

200 papers

We present the expansion of the two-pion exchange three-nucleon potential (TPE-3NP) to chiral order q^4, which corresponds to a subset of all possibilities at this order and is based on the \piN amplitude at O(q^3). Results encompass both…

Nuclear Theory · Physics 2008-11-26 S. Ishikawa , M. R. Robilotta

We present and apply a novel scheme for studying photon- and pion-nucleon scattering beyond the threshold region. Partial-wave amplitudes for the $\gamma\, N$ and $\pi N$ states are obtained by an analytic extrapolation of subthreshold…

High Energy Physics - Phenomenology · Physics 2015-03-13 A. Gasparyan , M. F. M. Lutz

We present details of the derivation of local chiral effective field theory interactions to next-to-next-to-leading order, and show results for nucleon-nucleon phase shifts and deuteron properties for these potentials. We then perform…

Nuclear Theory · Physics 2014-11-27 A. Gezerlis , I. Tews , E. Epelbaum , M. Freunek , S. Gandolfi , K. Hebeler , A. Nogga , A. Schwenk

We extract the next-to-next-to-leading order results for spin-flip generalized polarizabilities (GPs) of the nucleon from the spin-dependent amplitudes for virtual Compton scattering (VCS) at ${\cal O}(p^4)$ in heavy baryon chiral…

High Energy Physics - Phenomenology · Physics 2014-11-17 Chung-Wen Kao , Barbara Pasquini , Marc Vanderhaeghen

Employing the covariant baryon chiral perturbation theory, we calculate the leading and next-to-leading order two-pion exchange (TPE) contributions to $NN$ interaction up to order $O(p^3)$. We compare the so-obtained $NN$ phase shifts with…

Nuclear Theory · Physics 2020-11-18 Yang Xiao , Chun-Xuan Wang , Jun-Xu Lu , Li-Sheng Geng

Three instances are discussed in which results produced by chiral perturbation theory can be reliably pushed to high space-like values of transferred momenta: 1. nuclear interactions, 2. nucleon sigma-term and 3. space-like structure of the…

Nuclear Theory · Physics 2014-11-20 M. R. Robilotta

Chiral perturbation theory is the effective field theory of the strong interactions at low energies. We will give a short introduction to chiral perturbation theory for mesons and will discuss, as an example, the electromagnetic…

High Energy Physics - Phenomenology · Physics 2015-06-25 Stefan Scherer

In the scaling regime, amplitudes for backward virtual Compton scattering and hadron annihilation into two photons depend on structure functions that describe the hadron-photon transition at the partonic level. We construct simple…

High Energy Physics - Phenomenology · Physics 2009-11-11 B. C. Tiburzi

We argue that the minimal chiral background for the two-pion exchange nucleon-nucleon interaction has nowadays a rather firm conceptual basis, which entitles it to become a standard ingredient of any modern potential. In order to facilitate…

High Energy Physics - Phenomenology · Physics 2016-08-15 C. A. da Rocha , M. R. Robilotta

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

The production of mesons in nucleon-nucleon collisions is reviewed from the viewpoint of the meson-exchange picture. In the first part various possible production mechanisms and their relative importance are discussed. In addition, general…

Nuclear Theory · Physics 2010-12-13 C. Hanhart

From the subsubleading chiral three-nucleon force [intermediate-range contributions, published in Phys. Rev. C\,87, 054007 (2013)] a density-dependent NN-interaction $V_\text{med}$ is derived in isospin-symmetric nuclear matter. Following…

Nuclear Theory · Physics 2021-02-01 N. Kaiser

We study the interactions of an elementary pion with a nucleon made of constituent quarks and show that the enforcement of chiral symmetry requires the use of a two-body operator, whose form does not depend on the choice of the pion-quark…

High Energy Physics - Phenomenology · Physics 2008-11-26 C. M. Maekawa , M. R. Robilotta

Elastic scattering of pions from finite nuclei is investigated utilizing a contemporary, momentum--space first--order optical potential combined with microscopic estimates of second--order corrections. The calculation of the first--order…

Nuclear Theory · Physics 2009-10-22 C. M. Chen , D. J. Ernst , M. B. Johnson

I consider some selected topics in chiral perturbation theory (CHPT) as probed at colliders such as DA$\Phi$NE. Emphasis is put on processes involving pions in the isospin zero S-wave which require multi-loop calculations. These include the…

High Energy Physics - Phenomenology · Physics 2009-09-25 Ulf-G. Meißner

We derive from the subleading contributions to the chiral three-nucleon force (long-range terms, published in Phys.\,Rev.\,C\,77, 064004 (2008)) a density-dependent two-nucleon interaction $V_\text{med}$ in isospin-symmetric, spin-saturated…

Nuclear Theory · Physics 2021-04-09 N. Kaiser , B. Singh

We first describe a new way to access the chiral odd transversity parton distribution in the proton through the photoproduction of lepton pairs. The basic ingredient is the interference of the usual Bethe-Heitler or Drell-Yan amplitudes…

High Energy Physics - Phenomenology · Physics 2011-06-02 M. El Beiyad , B. Pire , L. Szymanowski , S. Wallon

Using the two-loop approximation of chiral perturbation theory, we calculate the momentum and density dependent nuclear spin-orbit strength $U_{ls}(p,k_f)$. This quantity is derived from the spin-dependent part of the interaction energy…

Nuclear Theory · Physics 2009-11-07 N. Kaiser

We analyze elastic-pion nucleon scattering to third order in the so-called small scale expansion. It is based on an effective Lagrangian including pions, nucleons and deltas as active degrees of freedom and counting external momenta, the…

High Energy Physics - Phenomenology · Physics 2009-10-31 Nadia Fettes , Ulf-G. Meißner

A review of photo-pion experiments on the nucleon in the near threshold region is presented. Comparisons of the results are made with the predictions of the low energy theorems of QCD calculated using chiral perturbation theory (ChPT) which…

Nuclear Experiment · Physics 2009-12-15 Aron M. Bernstein , Mohammad W. Ahmed , Sean Stave , Ying K. Wu , Henry R. Weller