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Related papers: CHIRAL BACKGROUND FOR THE TWO PION EXCHANGE NUCLEA…

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We consider two methods to find the effective parameters of the pion traversing a nuclear medium. One is the first order chiral perturbation theoretic evaluation of the pion pole contribution to the two-point function of the axial-vector…

Nuclear Theory · Physics 2009-11-10 S. Mallik , Sourav Sarkar

We calculate in (two-loop) chiral perturbation theory the local NN-potentials generated by the three-pion exchange diagrams with one insertion from the second order chiral effective pion-nucleon Lagrangian proportional to the low-energy…

Nuclear Theory · Physics 2009-11-07 Norbert Kaiser

We use proton-nucleus reaction data at intermediate energies to test the emerging new generation of chiral nucleon-nucleon (NN) potentials. Predictions from a high quality one-boson-exchange (OBE) force are used for comparison and…

Nuclear Theory · Physics 2009-11-07 F. Sammarruca , D. Alonso , E. J. Stephenson

We propose an arrangement of the most commonly invoked version of the two-nucleon chiral potential such that the low-lying amplitude zero of the 1S0 partial wave is captured at leading order of the effective expansion. Adopting other…

Nuclear Theory · Physics 2020-08-26 M. Sanchez Sanchez , N. A. Smirnova , A. M. Shirokov , P. Maris , J. P. Vary

A new tool which combines chiral perturbation theory and unitarity in coupled channels is applied with success to the study of the meson-meson interaction, extending the theoretical predictions up to sqrt{s} = 1.2 GeV, hence improving…

High Energy Physics - Phenomenology · Physics 2007-05-23 E. Oset , J. A. Oller , J. R. Peláez , Chiang Huan Ching , M. J. Vicente Vacas

The scalar-isoscalar term in the two-pion exchange $NN$ potential is abnormally large and does not respect the hierarchy of effects predicted by chiral perturbation theory. We argue that this anomaly is associated with non-perturbative…

Nuclear Theory · Physics 2009-01-16 M. R. Robilotta , G. R. S. Zarnauskas

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 derive a novel chiral power counting scheme for in-medium chiral perturbation theory with explicit nucleonic and pionic degrees of freedom coupled to external sources. It allows for a systematic expansion taking into account local as…

Nuclear Theory · Physics 2009-12-08 J. A. Oller , A. Lacour , U. -G. Meißner

We construct the leading order hyperon-nucleon potential in chiral effective field theory. We show that a good description of the available data is possible and discuss briefly further improvements of this scheme.

Nuclear Theory · Physics 2008-11-26 Henk Polinder , Johann Haidenbauer , Ulf-G. Meißner

We consider two-nucleon scattering close to threshold. Partial-wave amplitudes are obtained by an analytic extrapolation of subthreshold reaction amplitudes calculated in a relativistic formulation of chiral perturbation theory. The…

Nuclear Theory · Physics 2015-06-12 A. M. Gasparyan , M. F. M. Lutz , E. Epelbaum

The nucleon-nucleon ($NN$) potential is the residual interaction of the strong interaction in the low-energy region and is also the fundamental input to the study of atomic nuclei. Based on the non-perturbative properties of the quantum…

Nuclear Theory · Physics 2024-10-02 Ke Nan , Jinniu Hu , Hong Shen , Ying Zhang

We show how the unitarized description of pion nucleon scattering within Heavy Baryon Chiral Perturbation Theory can be considerably improved, by a suitable reordering of the expansion over the nucleon mass. Within this framework, the…

High Energy Physics - Phenomenology · Physics 2009-10-31 A. Gómez Nicola , J. Nieves , J. R. Peláez , E. Ruiz Arriola

We propose a novel way to formulate Chiral Perturbation Theory in a nuclear background, characterized by a static, non-uniform distribution of the baryon number that describes the finite nucleus. In the limiting case of a uniform…

High Energy Physics - Phenomenology · Physics 2015-06-25 L. Girlanda , A. Rusetsky , W. Weise

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 analyze the renormalization of the NN interaction at low energies and the deuteron bound state through the Chiral Two Pion Exchange Potential assumed to be valid from zero to infinity. The short distance Van der Waals singularity…

Nuclear Theory · Physics 2008-11-26 M. Pavon Valderrama , E. Ruiz Arriola

The parity-violating nucleon-nucleon (NN) potential is considered up to next-to-next-to leading order in heavy-baryon chiral perturbation theory. We include one-pion exchange at leading order and the two-pion exchange and two-nucleon…

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

After outlining the basic ideas of nuclear chiral perturbation theory, I discuss its application, presenting three examples which I believe are of great current interest: (1) Exchange currents in those cases where the leading chiral-order…

Nuclear Theory · Physics 2007-05-23 K. Kubodera

We investigate the reaction pn -> dpipi in the framework of Chiral Perturbation Theory. For the first time a complete calculation of the leading order contributions is presented. We identify various diagrams that are of equal importance as…

Nuclear Theory · Physics 2015-05-19 Bochao Liu , Vadim Baru , Johann Haidenbauer , Christoph Hanhart

I present some recent results on neutral pion photo- and electroproduction in the threshold region and discuss the low energy theorem for $E_{0+}$ and some novel ones for the $P$-waves. I also study the two-pion production process $\gamma N…

High Energy Physics - Phenomenology · Physics 2009-10-28 V. Bernard

We discuss renormalization of chiral nuclear forces in the 3P0 channel of N N scattering at next- to-next-to leading order (N2LO) if the one-pion exchange is treated nonperturbatively at leading order. The matrix elements of the subleading…

Nuclear Theory · Physics 2024-11-22 Rui Peng , Bingwei Long , Fu-Rong Xu
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