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Related papers: Coarse grained NN potential with Chiral Two Pion E…

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We evaluate the electric and magnetic polarizabilities of charged pions in the framework of chiral perturbation theory at next-to-leading order. This requires a two-loop evaluation of the Compton amplitude near threshold. We estimate the…

High Energy Physics - Phenomenology · Physics 2011-07-19 Urs Buergi

We consider nucleon-nucleon ($NN$) interactions from Chiral Effective Field Theory applying the $N/D$ method. The dynamical input is given by the discontinuity of the $NN$ partial-wave amplitudes across the left-hand cut (LHC) calculated in…

Nuclear Theory · Physics 2015-06-16 Zhi-Hui Guo , J. A. Oller , G. Rios

The astrophysical S-factor for proton-proton weak capture is calculated in chiral effective field theory over the center-of-mass relative-energy range 0--100 keV. The chiral two-nucleon potential derived up to next-to-next-to-next-to…

Nuclear Theory · Physics 2013-05-14 L. E. Marcucci , R. Schiavilla , M. Viviani

We present technical details of the evaluation of the elastic pi-pi scattering amplitude to two loops in chiral perturbation theory. In particular, we elaborate on the renormalization procedure at the two-loop order and on the evaluation of…

High Energy Physics - Phenomenology · Physics 2009-10-30 J. Bijnens , G. Colangelo , G. Ecker , J. Gasser , M. E. Sainio

It has been shown for the first time that $NN$ interaction, at least in some partial waves, can be quantitatively described by the superposition of a long-range one-pion exchange and a short-range mechanism based on the complex pole in the…

Nuclear Theory · Physics 2020-03-18 V. I. Kukulin , V. N. Pomerantsev , O. A. Rubtsova , M. N. Platonova

The available data on the forward charge exchange of nucleons on the deuteron up to 2GeV per nucleon are reviewed. The value of the inclusive nd->pnn/np->pn cross section ratio is sensitive to the fraction of spin-independent neutron-proton…

Nuclear Experiment · Physics 2014-11-20 F. Lehar , C. Wilkin

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

We calculate at two-loop order in chiral perturbation theory the electromagnetic corrections to the two-pion exchange nucleon-nucleon interaction that is generated by the isovector spin-flip $\pi\pi NN$ contact-vertex proportional to the…

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

Based on Compton scattering and meson photoproduction data the polarizabilities of the nucleon are precisely studied and well understood due to recent experimental and theoretical work based on nonsubtracted dispersion relations. The {\it…

High Energy Physics - Phenomenology · Physics 2014-08-01 Martin Schumacher

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

We report Quantum Monte Carlo calculations of weak transitions in $A\leq 10$ nuclei, based on the Norfolk two- and three-nucleon chiral interactions, and associated one- and two-body axial currents. We find that the contribution from…

Nuclear Theory · Physics 2020-08-26 G. B. King , L. Andreoli , S. Pastore , M. Piarulli , R. Schiavilla , R. B. Wiringa , J. Carlson , S. Gandolfi

The recently derived long-range two-pion exchange (TPE) contributions to the nuclear current operator which appear at next-to-leading order (NLO) of the chiral expansion are used to describe electromagnetic processes. We study their role in…

Nuclear Theory · Physics 2011-08-03 D. Rozpedzik , J. Golak , S. Kolling , E. Epelbaum , R. Skibinski , H. Witala , H. Krebs

We extend a recent chiral approach to nuclear matter by including the most general (momentum-independent) NN-contact interaction. Iterating this two-parameter contact-vertex with itself and with one-pion exchange the emerging energy per…

Nuclear Theory · Physics 2009-11-10 S. Fritsch , N. Kaiser

Motivated by the recent paper arXiv:2602.11815 [nucl-th], we calculate in these notes the spectral functions (i.e. imaginary parts) of the NN-potentials as they arise from $2\pi$-exchange with single and double Roper resonance excitation.…

Nuclear Theory · Physics 2026-02-26 Norbert Kaiser

We investigate the parity-violating analyzing power in neutron capture on the proton at thermal energies in the framework of chiral effective field theory. By combining this analysis with a previous analysis of parity violation in…

Nuclear Theory · Physics 2015-06-15 J. de Vries , N. Li , Ulf-G. Meißner , A. Nogga , E. Epelbaum , N. Kaiser

We study the nucleon-nucleon interaction up to next-to-next-to-leading order using time-ordered perturbation theory in the framework of manifestly Lorentz-invariant chiral effective field theory. We present the two-pion exchange…

Nuclear Theory · Physics 2022-09-12 Xiu-Lei Ren , E. Epelbaum , J. Gegelia

We calculate in (two-loop) chiral perturbation theory the local NN-potentials generated by certain classes of three-pion exchange diagrams. We stress that the chiral $3\pi NN$-contact vertex depends on the particular choice of the…

Nuclear Theory · Physics 2009-10-31 N. Kaiser

The electromagnetic corrections to the low energy scattering amplitude involving charged pions only are investigated at leading and next-to-leading orders in the two-flavour chiral expansion. As an application, the corresponding variation…

High Energy Physics - Phenomenology · Physics 2009-11-07 M. Knecht , A. Nehme

Pion-nucleon scattering, pion photoproduction, and nucleon Compton scattering are analyzed within a scheme based on the chiral Lagrangian. Partial-wave amplitudes are obtained by an analytic extrapolation of subthreshold reaction amplitudes…

High Energy Physics - Phenomenology · Physics 2011-02-11 A. M. Gasparyan , M. F. M. Lutz

Two-pion exchange parity-violating nucleon-nucleon interactions from recent effective field theories and earlier fully covariant approaches are investigated. The potentials are compared with the idea to obtain better insight on the role of…

Nuclear Theory · Physics 2008-11-26 B. Desplanques , C. H. Hyun , S. Ando , C. -P. Liu