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Related papers: Applied Chiral Perturbation Theory

200 papers

I discuss the whole mechanism to calculate isospin violation effects in the framework of CHPT. In order to get the correct size of isospin violation one has to include all non-isospin symmetric sources like the electromagnetic interaction,…

High Energy Physics - Phenomenology · Physics 2011-04-15 Guido Mueller

We use chiral perturbation theory (ChPT) to calculate the $\pi^- d$ scattering length with an accuracy of a few percent, including isospin-violating corrections both in the two- and three-body sector. In particular, we provide the technical…

Nuclear Theory · Physics 2011-11-22 V. Baru , C. Hanhart , M. Hoferichter , B. Kubis , A. Nogga , D. R. Phillips

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

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

I present a quick overview of the current status of Chiral perturbation theory in the meson sector. To illustrate the successes and some problems in the description of the phenomenology, I focus on a few selected examples that are relevant…

High Energy Physics - Phenomenology · Physics 2007-05-23 Gilberto Colangelo

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 derive a novel chiral power counting scheme for in-medium chiral perturbation theory with explicit nucleonic and pionic degrees of freedom coupled to external sources. It allows for a systematic expansion taking into account local as…

Nuclear Theory · Physics 2009-12-08 J. A. Oller , A. Lacour , U. -G. Meißner

The electric ${\alpha}_{\pi}$ and magnetic $\beta_{\pi}$ charged pion Compton polarizabilities are of fundamental interest in the low-energy sector of quantum chromodynamics (QCD).They are directly linked to the phenomenon of spontaneously…

High Energy Physics - Phenomenology · Physics 2018-06-19 Murray Moinester

I present an outline of chiral perturbation theory and discuss some recent developments in the field.

High Energy Physics - Phenomenology · Physics 2008-11-26 J. Gasser

We apply the formalism of Chiral Perturbation Theory out of thermal equilibrium to describe explosive production of pions via the parametric resonance mechanism. To lowest order the lagrangian is that of the Nonlinear Sigma Model where the…

High Energy Physics - Phenomenology · Physics 2009-11-07 A. Gomez Nicola

We use chiral perturbation theory to investigate hadronic properties in strong electric and magnetic fields. A strong-field power counting is employed, and results for pions and nucleons are obtained using Schwinger's proper-time method. In…

High Energy Physics - Phenomenology · Physics 2008-12-18 Brian C. Tiburzi

We compute the polarisability of the nucleon to leading order in chiral perturbation theory. The contributions from kaons and baryon resonances as intermediate states are included in addition to the contribution from pions and nucleons that…

High Energy Physics - Phenomenology · Physics 2009-10-22 Malcolm N. Butler , Martin J. Savage

I present higher loop order results for several calculations in Chiral perturbation Theory. 1) Two-loop results at finite volume for hadronic vacuum polarization. 2) A three-loop calculation of the pion mass and decay constant in…

High Energy Physics - Lattice · Physics 2018-04-18 Johan Bijnens

Interactions of $a_2, K^*_2, f_2$ and $f_2'$ tensor-mesons with low-energy $\pi, K, \eta, \eta'$ pseudo-scalar mesons are constrained by chiral symmetry. We derive a chiral Lagrangian of tensor mesons in which the tensor mesons are treated…

High Energy Physics - Phenomenology · Physics 2010-02-03 Chi-Keung Chow , Soo-Jong Rey

We have performed a theoretical study of the axial Nucleon to Delta(1232) ($N\to\Delta$) transition form factors up to one-loop order in covariant baryon chiral perturbation theory within a formalism in which the unphysical spin-1/2…

High Energy Physics - Phenomenology · Physics 2008-11-26 L. S. Geng , J. Martin Camalich , L. Alvarez-Ruso , M. J. Vicente Vacas

Recent developments in calculations of low energy nucleon properties utilizing effective chiral field theories with explicit spin 3/2 matter fields are presented. In particular, the role of Delta resonances in microscopic calculations of…

Nuclear Theory · Physics 2017-08-23 Thomas R. Hemmert

Near threshold neutral pion electroproduction on the deuteron is studied in the framework of heavy baryon chiral perturbation theory. We include the next-to-leading order corrections to the three-body contributions. We find an improved…

Nuclear Theory · Physics 2007-05-23 H. Krebs , V. Bernard , Ulf-G. Meißner

A brief discussion of the elastic pion-pion scattering amplitude to two loops in chiral perturbation theory is given. Some technical details of the evaluation of two-loop diagrams are addressed, and results relevant for the pionium decay…

High Energy Physics - Phenomenology · Physics 2007-05-23 M. E. Sainio

We explore the link between the chiral symmetry of QCD and the numerical results of the light-front quark model, analyzing both the two-point and three-point functions of the pion. Including the axial-vector coupling as well as the…

High Energy Physics - Phenomenology · Physics 2020-08-12 Ho-Meoyng Choi , Chueng-Ryong Ji

We analyse the extension of Chiral Perturbation Theory to describe a meson gas out of thermal equilibrium. For that purpose, we let the pion decay constant be a time-dependent function and work within the Schwinger-Keldysh contour…

High Energy Physics - Phenomenology · Physics 2016-09-06 A. Gomez Nicola