相关论文: Chiral effective-field theory with a resonance and…
We extend our previous analysis of the unitarized pion-nucleon scattering amplitude including up to fourth order terms in Heavy Baryon Chiral Perturbation Theory. We pay special attention to the stability of the generated Delta(1232…
Recent attempts to determine the pion polarizability by dispersion relations yield values that disagree with the predictions of chiral perturbation theory. These dispersion relations are based on specific forms for the absorptive part of…
We perform a relativistic chiral effective field theory calculation of the radiative pion photoproduction ($\gamma p \to \pi^0 p \gamma'$) in the $\Delta$-resonance region, to next-to-leading order in the ``delta-expansion''. This work is…
We present a theoretical study of the radiative pion photoproduction on the nucleon ($\gamma N \to \pi N \gamma'$) in the $\De$-resonance region, with the aim to determine the magnetic dipole moment (MDM) of the $\Delta^+(1232)$. The study…
An updated and extended analysis of the quark mass dependence of the nucleon's axial vector coupling constant g_A is presented in comparison with state-of-the-art lattice QCD results. Special emphasis is placed on the role of the…
The utility of chiral effective field theory, constructed in a manner in which loop contributions are suppressed as one moves outside the power-counting regime, is explored for baryon magnetic moments. Opportunities for the study of…
We will give a short introduction to the one-nucleon sector of chiral perturbation theory and will address the issue of a consistent power counting and renormalization. We will discuss the infrared regularization and the extended…
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…
I propose a prescription for separating the high- and low-energy contributions in effective field theories. This prescription allows a relativistic treatment of matter fields in chiral perturbation theory while the power counting remains…
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…
In light of recent experimental progress in determining the pressure and shear distributions in the proton, these quantities are calculated in a model with confined quarks supplemented by the pion field required by chiral symmetry. The…
Effective field theory is applied to finite-density systems with an unnaturally large scattering length, such as neutron matter. A new organizational scheme is identified and connected with an expansion in inverse powers of the number of…
These lectures introduce some of the basic ideas of effective field theories. The topics discussed include: relevant and irrelevant operators and scaling, renormalization in effective field theories, decoupling of heavy particles, power…
A brief introduction to the subject of chiral perturbation theory ($\chi$pt) is given, including a discussion of effective field theory and application to the upcoming Bates virtual Compton scattering measurement.
In a recent paper [1] a master formula has been presented for the power counting of a general effective field theory. We first show that this master formula follows immediately from the concept of chiral dimensions (loop counting), together…
In these lectures, the status of baryon chiral perturbation theory is reviewed. Particular emphasis is put on the two--flavor sector and the physics related to electromagnetic probes. I discuss in some detail the structure of the effective…
We discuss the pole mass and the width of the $\Delta(1232)$ resonance to third order in chiral effective field theory. In our calculation we choose the complex-mass renormalization scheme (CMS) and show that the CMS provides a consistent…
We analyse the proton Compton-scattering differential cross section for photon energies up to 325 MeV using Chiral Effective Field Theory and extract new values for the electric and magnetic polarisabilities of the proton. Our EFT treatment…
Chiral perturbation theory is nowadays a well-established approach to incorporate the chiral constraints from QCD. Nevertheless, for systems involving one baryon, the power counting which dictates the chiral order of observables is not as…
We perform a relativistic chiral effective-field theory calculation of the pion electroproduction off the nucleon ($e^- N \to e^- N \pi$) in the Delta(1232)-resonance region. After fixing the three low-energy constants, corresponding to the…