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We calculate the width of the delta resonance at leading two-loop order in baryon chiral perturbation theory. This gives a correlation between the leading pion-nucleon-delta and pion-delta couplings, which is relevant for the analysis of…

High Energy Physics - Phenomenology · Physics 2016-10-19 Jambul Gegelia , Ulf-G. Meißner , Dmitrij Siemens , De-Liang Yao

We analyze meson-baryon scattering lengths in the framework of covariant baryon chiral perturbation theory at leading one-loop order. We compute the complete set of matching relations between the dimension-two low-energy constants in the…

High Energy Physics - Phenomenology · Physics 2009-11-10 Maxim Mai , Peter C. Bruns , Bastian Kubis , Ulf-G. Meißner

Chiral perturbation theory is the low energy effective theory of the strong interactions for the light pseudoscalar degrees of freedom. This program is based on effective Lagrangian techniques and is an expansion in the powers of the…

High Energy Physics - Phenomenology · Physics 2007-05-23 B. Ananthanarayan

We calculate the octet baryon magnetic moments in covariant baryon chiral perturbation theory with the extended-on-mass-shell renormalization scheme up to next-to-next-to-leading order. At this order, there are nine low-energy constants,…

High Energy Physics - Phenomenology · Physics 2018-06-25 Yang Xiao , Xiu-Lei Ren , Jun-Xu Lu , Li-Sheng Geng , Ulf-G. Meißner

We report on our determination of the values of the one and two loop low energy constants appearing in the Chiral Perturbation Theory calculation of the pi-pi scattering amplitude. For this we use a precise sum rule determination of…

High Energy Physics - Phenomenology · Physics 2013-02-22 Guillermo Rios , Jenifer Nebreda , Jose R. Pelaez

Embedded in the historical context, we review recent progress in the development of nucleon-nucleon (NN) potentials based upon chiral effective field theory. A major breakthrough is the construction of the first NN potential at…

Nuclear Theory · Physics 2015-06-26 R. Machleidt , D. R. Entem

This work discusses reliability, possible obstacles and the future perspective of chiral extrapolation of lattice results. In the first part, chiral perturbation theory fits to lattice calculations of the nucleon mass are thoroughly…

High Energy Physics - Lattice · Physics 2007-05-23 Bernhard U. Musch

We test the convergence property of the chiral perturbation theory (ChPT) using a lattice QCD calculation of pion mass and decay constant with two dynamical quark flavors. The lattice calculation is performed using the overlap fermion…

High Energy Physics - Lattice · Physics 2019-08-14 J. Noaki , S. Aoki , T. W. Chiu , H. Fukaya , S. Hashimoto , T. H. Hsieh , T. Kaneko , H. Matsufuru , T. Onogi , E. Shintani , N. Yamada

We use power-counting arguments as an organizing principle to apply chiral perturbation theory, including an explicit $\Delta$, to the $p p \rightarrow p p \pi^0$ reaction near threshold. There are two lowest-order leading mechanisms…

Nuclear Theory · Physics 2008-11-26 T. D. Cohen , J. L. Friar , G. A. Miller , U. van Kolck

We study pion--nucleon scattering with a chiral lagrangian of pions, nucleons, and $\Delta$-isobars. The scattering amplitude is evaluated to one-loop $Q^3$ order, where $Q$ is a generic small momentum, using a new approach which is…

High Energy Physics - Phenomenology · Physics 2008-11-26 Paul J. Ellis , Hua-Bin Tang

In this talk we briefly describe some basic elements of chiral perturbation theory, $\chi PT$, and how the implementation of unitarity and other novel elements lead to a better expansion of the $T$ matrix for meson meson and meson baryon…

Dark pions are promising dark matter candidates, yet most analyses rely on leading-order (LO) chiral perturbation theory (ChPT). Motivated by the fact that, even for QCD pi-pi scattering, LO ChPT near threshold underestimates the isoscalar…

High Energy Physics - Phenomenology · Physics 2026-03-19 Yuki Watanabe

New constraints on resonance saturation in chiral perturbation theory are investigated. These constraints arise because each consistent saturation scheme must map to a representation of the full QCD chiral symmetry group. The low-energy…

High Energy Physics - Phenomenology · Physics 2009-10-31 Silas R. Beane

We present an analysis of the lowest-lying decuplet baryon masses in the covariant baryon chiral perturbation theory with the extended-on-mass-shell scheme up to next-to-next-to-next-to-leading order. In order to determine the $14$…

Nuclear Theory · Physics 2014-04-02 Xiu-Lei Ren , Li-Sheng Geng , Jie Meng

We present technical details of the evaluation of the elastic pi-pi scattering amplitude to two loops in chiral perturbation theory. In particular, we elaborate on the renormalization procedure at the two-loop order and on the evaluation of…

High Energy Physics - Phenomenology · Physics 2009-10-30 J. Bijnens , G. Colangelo , G. Ecker , J. Gasser , M. E. Sainio

We study the chiral expansion of the baryon octet and decuplet masses in the isospin limit. It is illustrated that a chiral expansion of the one-loop contributions is rapidly converging up to quark masses that generously encompasses the…

High Energy Physics - Lattice · Physics 2019-07-31 M. F. M. Lutz , Yonggoo Heo , Xiao-Yu Guo

A comparison of the linear sigma model (L$\sigma$M) and Chiral Perturbation Theory (ChPT) predictions for pion and kaon dynamics is presented. Lowest and next-to-leading order terms in the ChPT amplitudes are reproduced if one restricts to…

High Energy Physics - Phenomenology · Physics 2009-11-10 A. Bramon , R. Escribano , J. L. L. Martinez

We calculate chiral corrections to the semileptonic vector and axial quark coupling constants using a manifestly Lorentz covariant chiral quark approach up to order O(p4) in the two- and tree-flavor picture. These couplings are then used in…

High Energy Physics - Phenomenology · Physics 2008-11-26 Amand Faessler , Thomas Gutsche , Barry R. Holstein , Valery E. Lyubovitskij

We have systematically calculated the pseudoscalar Goldstone boson and charmed baryon scattering lengths to the third order with heavy baryon chiral perturbation theory. The scattering lengths can reveal the interaction of $K \Lambda_c$, $K…

High Energy Physics - Phenomenology · Physics 2015-06-12 Zhan-Wei Liu , Shi-Lin Zhu

The pion-nucleon scattering amplitudes are calculated in tree approximation with the use of the extended linear sigma model (ELSM) as well as heavy baryon chiral perturbation theory (HB$\chi$PT), and the non-relativistic forms of the ELSM…

Nuclear Theory · Physics 2009-11-11 W. P. Alvarez , K. Kubodera , F. Myhrer