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From recent charge exchange measurements in the extreme forward direction, an independent and precise determination of the pion nucleon coupling constant is possible. This determination has reopened the debate on the value of this…

High Energy Physics - Phenomenology · Physics 2012-07-19 F. Myhrer

Results for the antinucleon-nucleon ($\bar NN$) interaction obtained at next-to-next-to-next-to-leading order in chiral effective field theory (EFT) are reported. A new local regularization scheme is used for the pion-exchange contributions…

Nuclear Theory · Physics 2017-08-02 Ling-Yun Dai , Johann Haidenbauer , Ulf-G. Meißner

We consider low-energy nucleons at next-to-next-to-leading order in lattice chiral effective field theory. Three-body interactions first appear at this order, and we discuss several methods for determining three-body interaction…

Nuclear Theory · Physics 2009-07-22 Evgeny Epelbaum , Hermann Krebs , Dean Lee , Ulf-G. Meißner

We recently introduced a wave-mechanical model for quasi-elastic neutron scattering (QENS) in proteins. We call the model ELM for "Energy Landscape Model". We postulate that the spectrum of the scattered neutrons consists of lines of…

Biological Physics · Physics 2015-08-24 Hans Frauenfelder , Robert D. Young , Paul W. Fenimore

We review on a chiral power counting for in-medium chiral perturbation theory with nucleons and pions as explicit degrees of freedom coupled to external sources. It allows for a systematic expansion including both local and pion-mediated…

Nuclear Theory · Physics 2019-09-04 J. A. Oller

We present realistic models of pion-exchange three-nucleon interactions obtained by fitting the energies of all the 17 bound or narrow states of 3 <= A <= 8 nucleons, calculated with less than 2% error using the Green's function Monte Carlo…

Nuclear Theory · Physics 2008-11-26 Steven C. Pieper , V. R. Pandharipande , R. B. Wiringa , J. Carlson

Neutron matter is an ideal laboratory for nuclear interactions derived from chiral effective field theory since all contributions are predicted up to next-to-next-to-next-to-leading order (N$^3$LO) in the chiral expansion. By making use of…

Nuclear Theory · Physics 2016-12-12 C. Drischler , A. Carbone , K. Hebeler , A. Schwenk

Pion exchange is the central ingredient to nucleon-nucleon interactions used in nuclear structure calculations, and one pion exchange (OPE) enters at leading order in chiral effective field theory. In the $^{2S+1}L_J={^1S_0}$ partial wave,…

Nuclear Theory · Physics 2022-08-29 Chinmay Mishra , A. Ekström , G. Hagen , T. Papenbrock , L. Platter

We present a method to calculate neutron scattering cross sections for deformed nuclei using many--body wavefunctions described with multiple reference states. Nuclear states are calculated with the generator coordinate method using a low…

Nuclear Theory · Physics 2025-09-08 J. Boström , J. Rotureau , B. G. Carlsson , A. Idini

The leading-order nucleon-nucleon (NN) potential derived from chiral perturbation theory consists of one-pion exchange plus a short-distance contact interaction. We show that in the 1S0 and 3S1-3D1 channels renormalization of the…

Nuclear Theory · Physics 2008-11-26 C. -J. Yang , Ch. Elster , D. R. Phillips

The quark model symmetry can be adopted to establish relations between the low-energy constants (LECs) in the baryon chiral perturbation theory ($\chi PT$) if one assumes that a baryon-baryon-meson coupling is described equivalently by a…

High Energy Physics - Phenomenology · Physics 2022-10-07 Jun Jiang , Shao-Zhou Jiang , Shi-Yuan Li , Yan-Rui Liu , Zong-Guo Si , Hong-Qian Wang

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 highlight some of the recent advances in the application of chiral effective field theory (chiral EFT) with baryons to the $\pi N$ scattering process. We recall some problems that cast doubt on the applicability of chiral EFT to $\pi N$…

High Energy Physics - Phenomenology · Physics 2015-06-18 Jose Manuel Alarcón

Contributions of perturbative pions around a non-trivial fixed point are studied by utilizing di-baryon fields. We calculate ${}^1S_0$ and ${}^3S_1$ phase shifts for the $np$ scattering at low energies up to one-pion-exchange contributions.…

Nuclear Theory · Physics 2013-05-30 Shung-Ichi Ando , Chang Ho Hyun

The scattering amplitude of the pion-nucleon elastic scattering is calculated by the lowest-order approximation of the perturbative expansion with the non-perturbative term. The self-energy of nucleon is determined so as to give the…

Nuclear Theory · Physics 2022-04-22 Susumu Kinpara

These lectures are a pedagogical -- not comprehensive -- introduction to the applications of effective field theory in the context of nuclear and atomic physics. A common feature of these applications is the interplay between…

Nuclear Theory · Physics 2019-02-11 U. van Kolck

We construct a relativistic and unitary approach to 'high' energy pion- and photon-nucleon reactions taking the $\pi N, \pi \Delta$, $\rho N$, $\omega N$, $\eta N, K \Lambda, K \Sigma$ final states into account. Our scheme dynamically…

Nuclear Theory · Physics 2010-12-16 M. F. M. Lutz , Gy. Wolf , B. Friman

The high energy proton-neutron charge exchange scattering reaction is studied in an effective hadron model for the energy range of s from 45.9 to 414.61 GeV*GeV. The main features of the observed differential cross section, the forward peak…

High Energy Physics - Phenomenology · Physics 2007-05-23 Y. Yan , R. Tegen , T. Gutsche , V. E. Lyubovitskij , Amand Faessler

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

We consider the effective field theory (EFT) treatment of two-body systems with narrow resonances. Within this approach, an $s$-wave scattering amplitude can be expanded in powers of a typical momentum scale of a system $Q\ll \Lambda$,…

Nuclear Theory · Physics 2017-10-02 Mohammad H. Alhakami