相关论文: Recent Developments in Chiral Perturbation Theory
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…
The use of SU(3) chiral perturbation theory in the analysis of low energy meson-baryon interactions is discussed. It is emphasized that short distance effects, arising from propagation of Goldstone bosons over distances smaller than a…
There are indications that some theories with spontaneous symmetry breaking also feature a light scalar in their spectrum, with a mass comparable to the one of the Goldstone modes. In this paper, we perform the one-loop renormalization of a…
We discuss the use of cutoff methods in chiral perturbation theory. We develop a cutoff scheme based on the operator structure of the effective field theory that allows to suppress high momentum contributions in Goldstone boson loop…
Based on the (approximate) chiral symmetry of QCD Lagrangian and the bound state assumption of effective meson fields, a nonlinearly realized effective chiral Lagrangian for meson fields is obtained from integrating out the quark fields by…
Chiral lagrangians describing the interactions of Goldstone bosons in a theory possessing spontaneous symmetry breaking are effective, non-renormalizable field theories in four dimensions. Yet, in a momentum expansion one is able to extract…
In addition to fundamental symmetries playing a crucial role for establishing the Standard Model of fundamental interactions, approximate symmetries provide essential insight into the respective phenomena and shed light on the underlying…
Many of the quantities of interest at the precision frontier in particle physics require a good understanding of the strong interaction at low energies. The present talk reviews the theoretical framework used in this context. In particular,…
The effective theory based on combined chiral and heavy quark symmetry, the heavy meson chiral perturbation theory, is applied to studying the role of resonances in various processes of heavy mesons within and beyond the Standard Model.…
Electromagnetic interactions are incorporated into Heavy Hadron Chiral Perturbation Theory. Short and long distance magnetic moment contributions to the chiral Lagrangian are identified, and $M1$ radiative decays of heavy vector mesons and…
I discuss the problem of formulating the baryon chiral perturbation theory ($\chi$PT) in the presence of a light resonance, such as the $\Delta(1232)$, the lightest nucleon resonance. It is shown how to extend the power counting of $\chi$PT…
Heavy-baryon chiral perturbation theory (ChPT) at one loop fails in relating the pion-nucleon amplitude in the physical region and for subthreshold kinematics due to loop effects enhanced by large low-energy constants. Studying the chiral…
The medium modified hadron properties are studied by using the scale-chiral perturbation theory $\chi$PT$_\sigma$ in which the lightest scalar meson $f_0(500)$ is included as an explicit degree of freedom by regarding it as the…
Heavy baryon chiral perturbation theory including spin 3/2 delta resonances as effective degrees of freedom is reviewed. The theory admits a systematic expansion in the small scale $\epsilon$, where $\epsilon$ collectively denotes soft…
The description of strong interaction physics of low-lying resonances is out of the valid range of perturbative QCD. Chiral effective field theories have been developed to tackle the issue. Partial wave dynamics is the systematic tool to…
A scale-invariant chiral effective Lagrangian is constructed for octet pions and a dilaton figuring as Nambu-Goldstone bosons with vector mesons incorporated as hidden gauge fields. The Lagrangian is built to the next-to-leading order in…
Heavy baryon chiral perturbation theory ($\chi$PT), where the $\Delta$ resonance is included, is used in order to examine the axial charged-current component of the weak interaction process at low neutrino energies. At leading chiral order…
We discuss the systematics of power counting in general effective field theories, focussing on those that are nonrenormalizable at leading order. As an illuminating example we consider chiral perturbation theory gauged under the…
A review of photo-pion experiments on the nucleon in the near threshold region is presented. Comparisons of the results are made with the predictions of the low energy theorems of QCD calculated using chiral perturbation theory (ChPT) which…
Consideration of the analytic properties of pion-induced baryon self energies leads to new functional forms for the extrapolation of light baryon masses. These functional forms reproduce the leading non-analytic behavior of chiral…