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Related papers: $\bar d - \bar u$ asymmetry in the proton in chira…

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We study large-distance contributions to the nucleon parton densities in the transverse coordinate (impact parameter) representation based on generalized parton distributions (GPDs). Chiral dynamics generates a distinct component of the…

High Energy Physics - Phenomenology · Physics 2009-04-14 M. Strikman , C. Weiss

We present a parameter--free calculation of the dispersive and absorptive contributions to the pion--deuteron scattering length based on chiral perturbation theory. We show that once all diagrams contributing to leading order to this…

Nuclear Theory · Physics 2008-11-26 V. Lensky , V. Baru , J. Haidenbauer , C. Hanhart , A. Kudryavtsev , U. -G. Meißner

The near-threshold n p -> d pi0 cross section is calculated in chiral perturbation theory to next-to-leading order in the expansion parameter sqrt{M m_pi}/Lambda_chi. At this order irreducible pion loops contribute to the relevant…

Nuclear Theory · Physics 2008-11-26 A. Gardestig , D. R. Phillips , Ch. Elster

The neutral pion electroproduction on the proton is considered in the framework phenomenological model based on the PCAC, current algebra with hard pions and chiral symmetry breaking interaction. The s- wave differential cross-section of…

High Energy Physics - Phenomenology · Physics 2007-05-23 Alexander Tabachenko

We investigate the role of the delta isobar in the reaction $\pi d\to \pi d$ at threshold in chiral effective field theory. We discuss the corresponding power counting and argue that this calculation completes the evaluation of diagrams up…

Nuclear Theory · Physics 2008-11-26 V. Baru , J. Haidenbauer , C. Hanhart , A. Kudryavtsev , V. Lensky , U. -G. Meißner

We compute the light antiquark flavor asymmetry in the proton using the Chiral Quark Model ($\chi_{\rm QM}$). The distribution functions for the light antiquarks $\bar{d}(x)$ and $\bar{u}(x)$ have been extracted with the help of…

High Energy Physics - Phenomenology · Physics 2023-03-22 Shweta Choudhary , Pranjal Srivastava , Harleen Dahiya

Spin-dependent total pbar-d cross sections are considered using the optical theorem. For this aim the full spin dependence of the forward pbar-d elastic scattering amplitude is considered in a model independent way. The single-scattering…

Nuclear Theory · Physics 2009-03-12 Yu. N. Uzikov , J. Haidenbauer

Chiral symmetry of the 2-dimensional chiral Gross-Neveu model is broken explicitly by a bare mass term as well as a splitting of scalar and pseudo-scalar coupling constants. The vacuum and light hadrons - mesons and baryons which become…

High Energy Physics - Theory · Physics 2014-11-20 Christian Boehmer , Michael Thies

Chiral Effective Field Theory is for photon energies up to 200 MeV the tool to accurately determine the polarisabilities of the neutron from deuteron Compton scattering. A multipole analysis reveals that dispersive effects from an explicit…

Nuclear Theory · Physics 2008-11-26 Harald W. Griesshammer

Chiral symmetry serves as a guiding principle in low-energy hadron dynamics. An effective lagrangian, which explicitly breaks chiral symmetry via a small mass term, allows for a systematic method of calculating higher order corrections to…

Nuclear Theory · Physics 2007-05-23 F. Myhrer

We investigate the neutral pion photoproduction on the proton near threshold in covariant chiral perturbation theory with the explicit inclusion of Delta degrees of freedom. This channel is specially sensitive to chiral dynamics and the…

High Energy Physics - Phenomenology · Physics 2015-06-04 A. N. Hiller Blin , T. Ledwig , M. J. Vicente Vacas

The reaction pi N -> pi pi N is studied at tree level up to next-to-leading order in the framework of manifestly covariant baryon chiral perturbation theory with explicit Delta(1232) degrees of freedom. Using total cross section data to…

Nuclear Theory · Physics 2014-07-09 D. Siemens , V. Bernard , E. Epelbaum , H. Krebs , Ulf-G. Meißner

A surprisingly large charge symmetry violation of the sea quarks in the nucleon has been proposed in a recent article by Boros et al. as an explanation of the discrepancy between neutrino (CCFR) and muon (NMC) nucleon structure function…

High Energy Physics - Experiment · Physics 2010-02-02 A. Bodek , Q. Fan , M. Lancaster , K. S. McFarland , U. K. Yang

The density and temperature dependence of the nuclear symmetry free energy is investigated using microscopic two- and three-body nuclear potentials constructed from chiral effective field theory. The nuclear force models and many-body…

Nuclear Theory · Physics 2016-03-23 Corbinian Wellenhofer , Jeremy W. Holt , Norbert Kaiser

We calculate the $S$-factor for proton-proton fusion using chiral effective field theory interactions and currents. By performing order-by-order calculations with a variety of chiral interactions that are regularized and calibrated in…

Nuclear Theory · Physics 2023-07-26 Bijaya Acharya , Laura Elisa Marcucci , Lucas Platter

Nuclear parity violation is studied with polarized neutrons in the photodisintegration of the deuteron at low energies. A pionless effective field theory with di-baryon fields is used for the investigation. Hadronic weak interactions are…

Nuclear Theory · Physics 2015-05-30 J. W. Shin , S. -I. Ando , C. H. Hyun , S. W. Hong

Pion electro- and photoproduction off the nucleon close to threshold is studied in covariant baryon chiral perturbation theory at O($p^3$) in the extended-on-mass-shell scheme, with the explicit inclusion of the $\Delta(1232)$ resonance.…

High Energy Physics - Phenomenology · Physics 2021-01-04 Gustavo H. Guerrero Navarro , M. J. Vicente Vacas

Chiral perturbation theory is the effective field theory of the strong interactions at low energies. We will give a short introduction to chiral perturbation theory for mesons and will discuss, as an example, the electromagnetic…

High Energy Physics - Phenomenology · Physics 2015-06-25 Stefan Scherer

We calculate isospin breaking in pion-nucleon scattering in the threshold region in the framework of covariant baryon chiral perturbation theory. All effects due to quark mass differences as well as real and virtual photons are consistently…

High Energy Physics - Phenomenology · Physics 2011-11-22 Martin Hoferichter , Bastian Kubis , Ulf-G. Meißner

A brief review of Compton scattering off the deuteron in Chiral Effective Field Theory, including gauge invariance and the correct Thomson limit. We model-independently determine the iso-scalar, spin-independent dipole polarisabilities of…

Nuclear Theory · Physics 2017-08-23 Harald W. Griesshammer