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Nuclear potentials are known to exhibit a considerable degree of scheme dependence. For one- and two-pion exchange nucleon-nucleon (NN) potentials, unitary ambiguities start showing up at the level of the leading relativistic corrections to…

Nuclear Theory · Physics 2025-05-06 Victor Springer , Hermann Krebs , Evgeny Epelbaum

Pion photoproduction is analyzed with the chiral Lagrangian. Partial-wave amplitudes are obtained by an analytic extrapolation of subthreshold reaction amplitudes computed in chiral perturbation theory, where the constraints set by…

High Energy Physics - Phenomenology · Physics 2015-03-17 A. M. Gasparyan , M. F. M. Lutz

We analyse the interplay between nucleon-nucleon potentials deduced from chiral perturbation theory and a coarse grained representation of the short distance interactions by delta-shells potentials below a certain cut-off distance. While we…

Nuclear Theory · Physics 2013-01-30 Rodrigo Navarro Perez , J. E. Amaro , E. Ruiz Arriola

We consider the effective field theory of the NN system in a separable representation. The pionic part of the effective potential is included nonperturbatively and approximated by a separable potential. The use of a separable representation…

High Energy Physics - Phenomenology · Physics 2015-06-25 B. Krippa , B. L. G. Bakker

We derive the leading one-loop contribution to the one-pion exchange and short-range two-nucleon electromagnetic current operator in the framework of chiral effective field theory. The derivation is carried out using the method of unitary…

Nuclear Theory · Physics 2013-05-29 S. Koelling , E. Epelbaum , H. Krebs , U. -G. Meißner

We formulate lattice theories in which chiral symmetry is realized nonlinearly on the fermion fields. In this framework the fermion mass term does not break chiral symmetry. This property allows us to use the Wilson term to remove the…

High Energy Physics - Lattice · Physics 2014-11-17 S. Chandrasekharan , M. Pepe , F. D. Steffen , U. -J. Wiese

Hyperon-nucleon interactions are presented that are derived either in the conventional meson-exchange picture or within leading order chiral effective field theory. The chiral potential consists of one-pseudoscalar-meson exchanges and…

Nuclear Theory · Physics 2008-11-26 J. Haidenbauer , Ulf-G. Meißner , A. Nogga , H. Polinder

The relativistic interacting quark-diquark model of baryons, recently developed, is here extended to introduce a spin-isospin transition interaction into the mass operator. The refined version of the model is used to calculate the non…

High Energy Physics - Phenomenology · Physics 2016-08-02 M. De Sanctis , J. Ferretti , E. Santopinto , A. Vassallo

Underlying a general noncommutative algebra with both noncommutative coordinates and noncommutative momenta in a (1+1)-dimensional spacetime, a chiral boson Lagrangian with manifest Lorentz covariance is proposed by linearly imposing a…

High Energy Physics - Theory · Physics 2009-11-10 Yan-Gang Miao , Harald J. W. Müller-Kirsten , Dae Kil Park

We construct interactions of nucleons N with higher-spin resonances R invariant under point and gauge transformations of the Rarita-Schwinger field. It is found for arbitrarily high spin of a resonance that the requirement of point- and…

High Energy Physics - Phenomenology · Physics 2013-03-21 G. Vereshkov , N. Volchanskiy

We study the short-range nucleon-nucleon interaction in a nonrelativistic chiral constituent quark model by diagonalizing a Hamiltonian containing a linear confinement and a Goldstone boson exchange interaction between quarks. A finite…

High Energy Physics - Phenomenology · Physics 2009-10-31 D. Bartz , Fl. Stancu

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

A simple model of a composite nucleon is developed in which a fermion and a boson, representing quark and diquark constituents of the nucleon, form a bound state owing to a contact interaction. Photon and pion couplings to the quark provide…

Nuclear Theory · Physics 2008-11-26 J. A. Tjon , S. J. Wallace

The meson-exchange current in nuclei, a long-standing problem in nuclear physics, is described in modern theory of strong interactions, namely, QCD expressed in terms of effective chiral Lagrangian field theory. Some old results are given a…

Nuclear Theory · Physics 2007-05-23 Mannque Rho

The loop expansion is applied to a chiral effective hadronic lagrangian; with the techniques of Infrared Regularization, it is possible to separate out the short-range contributions and to write them as local products of fields that are…

Nuclear Theory · Physics 2008-11-26 Jeff McIntire , Ying Hu , Brian D. Serot

We construct the effective chiral Lagrangian involving hadronic and electromagnetic interactions originating from the QCD theta term. We impose vacuum alignment at both quark and hadronic levels, including field redefinitions to eliminate…

High Energy Physics - Phenomenology · Physics 2014-11-20 E. Mereghetti , W. H. Hockings , U. van Kolck

We study the nucleon-nucleon interaction within a chiral constituent quark model which reproduces succesfully the baryon spectra. We calculate the 3S1 and 1S0 phase shifts by using the resonating group method. They clearly indicate the…

High Energy Physics - Phenomenology · Physics 2009-10-31 D. Bartz , Fl. Stancu

We analyze magnetic and axial two-nucleon contact terms in a combined large-$N_c$ and pionless effective field theory expansion. These terms play important roles in correctly describing, e.g., the low-energy cross section of radiative…

Nuclear Theory · Physics 2020-05-27 Thomas R. Richardson , Matthias R. Schindler

We extend a chiral effective field theory approach to the $\Lambda$-nuclei interaction with the inclusion of the decuplet baryons. More precisely, we study the contributions due to the long-range two-pion exchange, with $\Sigma$ and…

Nuclear Theory · Physics 2007-05-23 J. Martín Cámalich

The non-Abelian tensor gauge fields take value in extended Poincar\'e algebra. In order to define the invariant Lagrangian we introduce a vector variable in two alternative ways: through the transversal representation of the extended…

High Energy Physics - Theory · Physics 2018-01-17 George Savvidy