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Related papers: Scalar form factors and nuclear interactions

200 papers

We have performed a theoretical study of the axial Nucleon to Delta(1232) ($N\to\Delta$) transition form factors up to one-loop order in covariant baryon chiral perturbation theory within a formalism in which the unphysical spin-1/2…

High Energy Physics - Phenomenology · Physics 2008-11-26 L. S. Geng , J. Martin Camalich , L. Alvarez-Ruso , M. J. Vicente Vacas

We derive the subleading contributions to the two-pion-one-pion exchange and ring three-nucleon force topologies emerging at next-to-next-to-next-to-next-to-leading order in chiral effective field theory. The resulting expressions do not…

Nuclear Theory · Physics 2013-06-05 Hermann Krebs , Ashot Gasparyan , Evgeny Epelbaum

We calculate the spin-polarizabilities of the nucleon by means of dispersion relation, where the pion photoproduction amplitude predicted by chiral soliton model is utilized. We consider the $N\pi$ and $\Delta\pi$ channels in the…

Nuclear Theory · Physics 2009-10-31 Y. Tanushi , S. Saito , M. Uehara

We study the two-pion exchange potential at next-to-next-to-leading order in chiral effective field theory. We propose a new cut-off scheme for the pion loop integrals based on spectral function regularization. We show that this method…

Nuclear Theory · Physics 2014-11-18 Evgeny Epelbaum , Walter Glöckle , Ulf-G. Meißner

We report on shell-model calculations employing effective interactions derived from a new realistic nucleon-nucleon (NN) potential based on chiral effective field theory. We present results for 18O, 134Te, and 210Po. Our results are in…

Nuclear Theory · Physics 2009-11-07 L. Coraggio , A. Covello , A. Gargano , N. Itaco , T. T. S. Kuo , D. R. Entem , R. Machleidt

We present a calculation of pion electromagnetic and scalar form factors in two-flavor QCD with the non-perturbatively O(a)-improved Wilson fermion. Chiral extrapolation of the corresponding charge radius is discussed based on the chiral…

As a first step toward circumventing the difficulty to obtain an attractive isospin-independent NN spin-orbit force from Skyrme-type models involving only pions, we investigate an improved Skyrme Lagrangian that incorporates the…

High Energy Physics - Phenomenology · Physics 2016-09-06 Abdellatif Abada

We use a recently improved version of the chiral nucleon-nucleon potential at next-to-next-to-leading order to calculate the $^1S_0$ pairing gap in isospin-symmetric nuclear matter. The pairing potential consists of the long-range one- and…

Nuclear Theory · Physics 2009-11-10 N. Kaiser , T. Niksic , D. Vretenar

We present a comprehensive analysis of form factors for two light pseudoscalar mesons induced by scalar, vector, and tensor quark operators. The theoretical framework is based on a combination of unitarized chiral perturbation theory and…

High Energy Physics - Phenomenology · Physics 2021-04-28 Yu-Ji Shi , Chien-Yeah Seng , Feng-Kun Guo , Bastian Kubis , Ulf-G. Meißner , Wei Wang

We extend a recent calculation of the nuclear energy density functional in the framework of chiral perturbation theory by computing the isovector surface and spin-orbit terms: $(\vec \nabla \rho_p- \vec \nabla \rho_n)^2 G_d(\rho)+ (\vec…

Nuclear Theory · Physics 2014-11-20 N. Kaiser

We calculate the impact of the complete set of two-pion exchange contributions at chiral order four (also known as next-to-next-to-next-to-leading order, N3LO) on peripheral partial waves of nucleon-nucleon scattering. Our calculations are…

Nuclear Theory · Physics 2009-11-07 D. R. Entem , R. Machleidt

For decades, a lot of work has been devoted to the problem of constructing a non-trivial quantum field theory in four-dimensional space time. This letter addresses the attempts to construct an algebraic quantum field theory in the framework…

High Energy Physics - Theory · Physics 2019-04-12 Andreas Aste

We extend our analysis for scalar fields in a Robertson-Walker metric to the electromagnetic field and Dirac fields by the method of invariants. The issue of the relation between conformal properties and particle production is re-examined…

General Relativity and Quantum Cosmology · Physics 2008-11-26 F. Finelli , A. Gruppuso , G. Venturi

Corrections to $K\rightarrow\pi\pi\pi$ induced by vector and scalar meson exchange are investigated within chiral perturbation theory.

High Energy Physics - Phenomenology · Physics 2009-10-22 S. Fajfer

The pion structure function is investigated in a simple model, where pion and constituent quark fields are coupled through the simplest pseudoscalar coupling. The imaginary part of the forward gamma* pi-> gamma* pi scattering amplitude is…

High Energy Physics - Phenomenology · Physics 2009-11-07 F. Bissey , J. R. Cudell , J. Cugnon , M. Jaminon , J. P. Lansberg , P. Stassart

The pseudo scalar form factor, which represents the pseudo scalar quark density distribution due to finite quark masses on the nucleon, is shown to manifest itself with the induced pseudo scalar form factor in the $L_0^+$ amplitude for the…

Nuclear Theory · Physics 2008-11-26 Myung Ki Cheoun , K. S. Kim

This is a revised version of a talk given at the Chiral Dynamics Workshop at M.I.T., July 25, 1994. It reports results in three areas: (1) The isospin-violating interactions between one non-relativistic nucleon and any number of soft pions…

High Energy Physics - Phenomenology · Physics 2009-10-28 Steven Weinberg

Within the framework of chiral effective field theory, perturbative calculation for $NN$ scattering is carried out in partial waves with orbital angular momentum $L \geqslant 1$. The primary goal is to identify the lowest angular momenta at…

Nuclear Theory · Physics 2019-02-26 Shaowei Wu , Bingwei Long

We present a determination of the pion-nucleon sigma-term based on a novel analysis of the $\pi N$ scattering amplitude in Lorentz covariant baryon chiral perturbation theory renormalized in the extended-on-mass-shell scheme. This…

High Energy Physics - Phenomenology · Physics 2015-06-03 J. Martin Camalich , J. M. Alarcon , J. A. Oller

We discuss a relativistic chiral theory of nuclear matter with $\sigma$ and $\omega$ exchange using a formulation of the $\sigma$ model in which all the chiral constraints are automatically fulfilled. We establish a relation between the…

Nuclear Theory · Physics 2008-11-26 M. Ericson , G. Chanfray