scholarly journals Chiral perturbation theory and final state interactions in meson decays

2012 ◽  
Author(s):  
Bastian Kubis
2019 ◽  
Vol 199 ◽  
pp. 01023
Author(s):  
Wencheng Yan

The BESIII experiment has accumulated the world’s largest data samples of 1.3 billion J/ψ events and 0.45 billion ψ(3686) events, which provide a unique opportunity to investigate light meson decays. The η and η′ decays are sensitive tools for investigations of π − π and η − π interactions, symmetry breaking, and serve as a test of chiral perturbation theory. In recent years considerable results on η and η′ decays were achieved at the BESIII experiment. In this proceeding, we present the significant progresses on amplitude analyses of Dalitz decays η' → 3π,η' → ηππ, and radiative decay η' → γπ+π−, η' → γγπ0. Additionally, the $a_0^0\left( {980} \right) - {f_0}\left( {980} \right)$ mixing is an important probe to the nature of those two lightest scalar mesons. The first observation of $a_0^0\left( {980} \right) - {f_0}\left( {980} \right)$ mixing is also presented, which will help to improve the understanding of the nature of $a_0^0\left( {980} \right)$ and f0(980).


1992 ◽  
Vol 07 (29) ◽  
pp. 7305-7338 ◽  
Author(s):  
A.N. IVANOV ◽  
M. NAGY ◽  
N.I. TROITSKAYA

The chiral perturbation theory is developed at the quark level within the extended Nambu-Jona-Lasinio model, which we used for the low-energy approximation of QCD in the leading order of the large N expansion. In terms of constituent-quark loop diagrams we analyze all of the main low-energy effects caused by the first order corrections in the current-quark-mass expansions. For the correct description of the η→3π decays we confirm the important role of the final-state interaction quoted by Gasser and Leutwyler.


2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
Thomas Vonk ◽  
Feng-Kun Guo ◽  
Ulf-G. Meißner

Abstract In the past, the axion-nucleon coupling has been calculated in the framework of SU(2) heavy baryon chiral perturbation theory up to third order in the chiral power counting. Here, we extend these earlier studies to the case of heavy baryon chiral perturbation theory with SU(3) flavor symmetry and derive the axion coupling to the full SU(3) baryon octet, showing that the axion also significantly couples to hyperons. As studies on dense nuclear matter suggest the possible existence of hyperons in stellar objects such as neutron stars, our results should have phenomenological implications related to the so-called axion window.


2019 ◽  
Vol 34 (21) ◽  
pp. 1950113
Author(s):  
V. A. Franke ◽  
M. Yu. Malyshev ◽  
S. A. Paston ◽  
E. V. Prokhvatilov ◽  
M. I. Vyazovsky

Light front (LF) Hamiltonian for QED in [Formula: see text] dimensions is constructed using the boson form of this model with additional Pauli–Villars-type ultraviolet regularization. Perturbation theory, generated by this LF Hamiltonian, is proved to be equivalent to usual covariant chiral perturbation theory. The obtained LF Hamiltonian depends explicitly on chiral condensate parameters which enter in a form of some renormalization of coupling constants. The obtained results can be useful when one attempts to apply LF Hamiltonian approach for [Formula: see text]-dimensional models like QCD.


1987 ◽  
Vol 189 (3) ◽  
pp. 363-368 ◽  
Author(s):  
Gerhard Ecker ◽  
Antonio Pich ◽  
Eduardo De Rafael

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