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Related papers: Dispersive Approach to Chiral Perturbation Theory

200 papers

We include in a systematic way the eta' in baryon chiral perturbation theory. The most general relativistic effective Lagrangian describing the interaction of the lowest lying baryon octet with the Goldstone boson octet and the eta' is…

High Energy Physics - Phenomenology · Physics 2009-10-31 B. Borasoy

The existing Chiral Perturbation Theory (ChPT) calculations at order $p^6$ are reviewed. The principles of ChPT and how they are used are introduced. The main part is a review of the two- and three-flavour full two-loop calculations and…

High Energy Physics - Phenomenology · Physics 2008-11-26 Johan Bijnens

We derive the scattering amplitude for Goldstone bosons of chiral symmetry off the pseudoscalar charmed mesons up to leading one-loop order in a covariant chiral effective field theory, using the so-called extended-on-mass-shell…

High Energy Physics - Phenomenology · Physics 2015-11-09 De-Liang Yao , Meng-Lin Du , Feng-Kun Guo , Ulf-G. Meißner

We complete the analysis of twist-two generalized parton distributions of the nucleon in one-loop order of heavy-baryon chiral perturbation theory. Extending our previous study of the chiral-even isosinglet sector, we give results for…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Diehl , A. Manashov , A. Schafer

The chiral perturbation theory (ChPT) of pions is extended to include vector mesons as well as pertinent degrees of freedom. By counting the typical momentum scale of vector mesons as order of $Q$ and vector meson masses as of the order of…

High Energy Physics - Phenomenology · Physics 2024-01-23 Tae-Sun Park

The talk contains a short introduction to mesonic Chiral Perturbation Theory (ChPT). In addition four disparate areas where some progress has been made in recent years are discussed. These are the last fit of the order $p^4$…

High Energy Physics - Phenomenology · Physics 2013-01-30 Johan Bijnens

The statement of the authors of the article Phys. Rev. C 77, 065211 (2008) that spurious singularities occur in the dispersion relation approach, where imaginary parts of the amplitudes of the process \gamma\gamma->\pi\pi are saturated by…

High Energy Physics - Phenomenology · Physics 2014-11-18 L. V. Fil'kov , V. L. Kashevarov

Constraints on the parameters in the one- and two-loop pion-pion scattering amplitudes of standard chiral perturbation theory are obtained from explicitly crossing-symmetric sum rules. These constraints are based on a matching of the chiral…

High Energy Physics - Phenomenology · Physics 2009-08-27 G. Wanders

We construct the complete effective chiral pion-nucleon Lagrangian to third order in small momenta based on relativistic chiral perturbation theory. We then perform the so-called heavy baryon limit and construct all terms…

High Energy Physics - Phenomenology · Physics 2009-10-31 Nadia Fettes , Ulf-G. Meißner , Sven Steininger

We discuss the meson-meson scattering and finite energy sum rule(FESR), based on the one-loop calculation within U(3) chiral perturbation theory. First we obtain the pertinent resonance spectroscopy from the unitarized partial wave…

High Energy Physics - Phenomenology · Physics 2012-08-03 Zhi-Hui Guo , J. A. Oller , J. Ruiz de Elvira

Reordering of the chiral perturbation series, proposed recently by Becher and Leutwyler in the framework of SU(2) baryonic ChPT, is applied to the SU(3) case. This results in improved convergence of the chiral expansion of static properties…

High Energy Physics - Phenomenology · Physics 2009-10-31 Martin Mojzis , Joachim Kambor

This article provides a pedagogical introduction to the basic concepts of chiral perturbation theory and is designed as a text for a two-semester course on that topic. Chapter 1 serves as a general introduction to the empirical and…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Scherer

The perturbation theory for critical points of causal variational principles is developed. We first analyze the class of perturbations obtained by multiplying the universal measure by a weight function and taking the push-forward under a…

Mathematical Physics · Physics 2020-08-26 Felix Finster

We consider two-nucleon scattering close to threshold. Partial-wave amplitudes are obtained by an analytic extrapolation of subthreshold reaction amplitudes calculated in a relativistic formulation of chiral perturbation theory. The…

Nuclear Theory · Physics 2015-06-12 A. M. Gasparyan , M. F. M. Lutz , E. Epelbaum

We consider the $\pi\pi$ scattering amplitude obtained by Colangelo, Gasser and Leutwyler (CGL), using dispersion relations and chiral perturbation theory to two loops. We point out that the input used by CGL for energies above 1.42 GeV is…

High Energy Physics - Phenomenology · Physics 2009-11-10 F. J. Yndurain

We reexamine critically the chiral expansion for the baryon magnetic moments including the contributions from loops which involve intermediate octet and decuplet baryons. We find that, contrary to some claims, the nonanalytic loop…

High Energy Physics - Phenomenology · Physics 2009-10-30 Loyal Durand , Phuoc Ha

We evaluate the amplitude for $\gamma \gamma \rightarrow \pi^0 \pi^0$ to two loops in chiral perturbation theory. The three new counterterms which enter at this order in the low-energy expansion are estimated with resonance saturation. We…

High Energy Physics - Phenomenology · Physics 2011-07-19 S. Bellucci , J. Gasser , M. E. Sainio

A complete calculation of the corrections to pion-deuteron scattering length up to order $\chi^{3/2}$ with $\chi=m_{\pi}/M_{N}$ is performed. The calculation includes the dispersive contributions and corrections due to the explicit…

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

We compare the linear meson model and chiral perturbation theory in next to leading order in the quark mass expansion. In particular, we compute the couplings L_4--L_8 of chiral perturbation theory as functions of the parameters of the…

High Energy Physics - Phenomenology · Physics 2011-09-13 Dirk-U. Jungnickel , C. Wetterich

We discuss convergence issues as well as short distance constraints on the deuteron wave functions based on chiral perturbation theory relevant to pion deuteron scattering. Non-analytical terms arise in the multiple scattering series for…

Nuclear Theory · Physics 2007-05-23 M. Pavon Valderrama , E. Ruiz Arriola