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Related papers: Two-pion exchange NN potential from Lorentz-invari…

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We investigate neutral pion electroproduction off protons in the framework of heavy baryon chiral perturbation theory. The chiral expansion of the S--wave multipoles $E_{0+}$ and $L_{0+}$ is carried out to three orders. There appear several…

High Energy Physics - Phenomenology · Physics 2009-10-28 V. Bernard , N. Kaiser , Ulf-G. Meißner

The objectives of the present work are twofold. The first is to address and resolve some of the differences present in independent, chiral-effective-field-theory (\chiEFT) derivations up to one loop, recently appeared in the literature, of…

Nuclear Theory · Physics 2015-06-12 M. Piarulli , L. Girlanda , L. E. Marcucci , S. Pastore , R. Schiavilla , M. Viviani

We present calculations of the two-pion-exchange contribution to proton-proton scattering at 90 degrees using form factors appropriate for representing the distribution of the constituent partons of the nucleon. Talk given at MENU2001,…

Nuclear Theory · Physics 2007-05-23 W. R. Gibbs , Benoit Loiseau

The charge-dependent nucleon-nucleon ($NN$) interactions are crucial in understanding the nuclear structure and reaction problems. This work explores the charge-dependent $NN$ interaction in covariant chiral effective field theory. By…

Nuclear Theory · Physics 2025-04-23 Yang Xiao , Jun-Xu Lu , Li-Sheng Geng

I outline the effective field theory (EFT) calculation of nucleon-nucleon scattering which was recently carried out to next-to-next-to-leading order (NNLO) by Noam Shoresh and myself. In this calculation only potential pion contributions…

Nuclear Theory · Physics 2007-05-23 G. Rupak , N. Shoresh

The non-mesonic weak decay of $\Lambda$--hypernuclei is studied within a one-meson-exchange potential supplemented by a chirally motivated two-pion-exchange mechanism. The effects of final state interactions on the outgoing nucleons are…

Nuclear Theory · Physics 2008-11-26 C. Chumillas , G. Garbarino , A. Parreno , A. Ramos

We address the issue of a consistent power counting scheme in manifestly Lorentz-invariant baryon chiral perturbation theory. We discuss the inclusion of vector mesons in the calculation of the nucleon electromagnetic form factors. We…

High Energy Physics - Phenomenology · Physics 2008-11-26 S. Scherer

We reformulate the analysis of nuclear parity-violation (PV) within the framework of effective field theory (EFT). To order Q, the PV nucleon-nucleon (NN) interaction depends on five a priori unknown constants that parameterize the…

Nuclear Theory · Physics 2014-11-18 Shi-Lin Zhu , C. M. Maekawa , B. R. Holstein , M. J. Ramsey-Musolf , U van Kolck

Chirally invariant Lagrangian containing nucleon, pion and chiral scalar fields is considered. A consistent scheme is proposed for obtaining the nonrelativistic operator of pion absorption by NN-pair taking into account the chiral scalar…

Nuclear Theory · Physics 2007-05-23 D. A. Zaikin , I. I. Osipchuk

I review recent progress made in the description of pion-nucleon scattering, the $\sigma$--term, the scalar form factor and the strangeness content of the nucleon in the framework of heavy baryon chiral perturbation theory. Other topics are…

High Energy Physics - Phenomenology · Physics 2011-04-15 Ulf-G. Meißner

We consider nucleon-nucleon (NN) interactions from chiral effective field theory. In this work we restrict ourselves to the elastic NN scattering. We apply the N/D method to calculate the NN partial waves taking as input the one-pion…

Nuclear Theory · Physics 2015-05-28 M. Albaladejo , J. A. Oller

A recently proposed super-heat-kernel technique is applied to heavy baryon chiral perturbation theory with two flavours. A previous result for the one-loop divergences of the pion-nucleon system is confirmed, giving at the same time an…

High Energy Physics - Phenomenology · Physics 2011-09-13 H. Neufeld

We calculate shell-model matrix elements of the axial-charge exchange current operators that have been obtained up to the next-to-leading order from heavy-fermion chiral perturbation theory. It is found that loop corrections to the soft…

Nuclear Theory · Physics 2009-10-28 Tae-Sun Park , Ian S. Towner , Kuniharu Kubodera

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

The main progress in the field of nucleon-nucleon (NN) potentials, which we have seen in recent years, is the construction of some very quantitative (high-quality/high-precision) NN potentials. These potentials will serve as excellent input…

Nuclear Theory · Physics 2007-05-23 R. Machleidt

We review recent progress in our understanding of elastic and inelastic pion reactions on two nucleon systems from the point of view of effective field theory. The discussion includes pion-deuteron scattering, gamma d to pi-nn, and NN to…

Nuclear Theory · Physics 2007-05-23 C. Hanhart

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

In view of ongoing experimental activities to determine the pion polarizabilities, we have started to recalculate the available two-loop expressions in the framework of chiral perturbation theory, because they have never been checked…

High Energy Physics - Phenomenology · Physics 2008-11-26 Juerg Gasser , Mikhail A. Ivanov , Mikko E. Sainio

We consider a new approach to the nucleon-nucleon scattering problem in the framework of the higher-derivative formulation of baryon chiral perturbation theory. Starting with a Lorentz-invariant form of the effective Lagrangian we work out…

Nuclear Theory · Physics 2008-11-26 D. Djukanovic , J. Gegelia , S. Scherer , M. R. Schindler

Motivated by the recent lattice QCD study of the $DD^*$ interaction at unphysical quark masses, we perform a theoretical study of the $DD^*$ interaction in covariant chiral effective field theory (ChEFT). In particular, we calculate the…

High Energy Physics - Phenomenology · Physics 2023-11-14 Qing-Yu Zhai , Ming-Zhu Liu , Jun-Xu Lu , Li-Sheng Geng