scholarly journals Revisiting $\bar{K}N$ scattering and relevant baryon resonances

2014 ◽  
Vol 29 ◽  
pp. 1460242
Author(s):  
Zhi-Hui Guo ◽  
J. A. Oller
Keyword(s):  
Experimental Data ◽  
Perturbation Theory ◽  
Chiral Perturbation Theory ◽  
Wave Scattering ◽  
Threshold Behavior ◽  
S Wave ◽  
Chiral Perturbation ◽  
Baryon Spectroscopy ◽  
Baryon Resonances

We give an updated study on meson-baryon scattering within the framework of unitary chiral perturbation theory. We focus on S-wave scattering with strangeness -1 channel. After fixing the unknown couplings through fitting to experimental data, we then analyze the baryon spectroscopy and the sub-threshold behavior of the [Formula: see text] amplitude. We end with a summary and a brief outlook.

scholarly journals S-wave scattering in chiral perturbation theory with resonances

2000 ◽  
Vol 587 (1-3) ◽  
pp. 331-362 ◽  
Author(s):  
Matthias Jamin ◽  
José Antonio Oller ◽  
Antonio Pich
Keyword(s):  
Perturbation Theory ◽  
Chiral Perturbation Theory ◽  
Wave Scattering ◽  
S Wave ◽  
Chiral Perturbation

Resonant and non-resonant contributions of B → K∗(p1,𝜖1){Kπ,ππ,KK} decay modes

2019 ◽  
Vol 34 (06) ◽  
pp. 1950043
Author(s):  
Mahboobeh Sayahi
Keyword(s):  
Experimental Data ◽  
Perturbation Theory ◽  
Chiral Perturbation Theory ◽  
Branching Ratio ◽  
Heavy Meson ◽  
Chiral Perturbation ◽  
Decay Modes ◽  
Qcd Factorization ◽  
Three Body ◽  
Good Agreement

In this paper, the non-leptonic three-body decays [Formula: see text], [Formula: see text], [Formula: see text] are studied by introducing two-meson distribution amplitude for the [Formula: see text], [Formula: see text] and [Formula: see text] pairs in naive and QCD factorization (QCDF) approaches, such that the analysis is simplified into quasi-two body decays. By considering that the vector meson is being ejected in factorization, the resonant and non-resonant contributions are analyzed by using intermediate mesons in Breit–Wigner resonance formalism and the heavy meson chiral perturbation theory (HMChPT), respectively. The calculated values of the resonant and non-resonant branching ratio of [Formula: see text], [Formula: see text] and [Formula: see text] decay modes are compared with the experimental data. For [Formula: see text] and [Formula: see text], the non-resonant contributions are about 70–80% of experimental data, for which the total results by considering resonant contributions are in good agreement with the experiment.

Convergence issues in baryon chiral perturbation theory for the reaction π + N → 2π + N

2007 ◽  
Vol 85 (6) ◽  
pp. 663-669
Author(s):  
N Mobed ◽  
J Zhang ◽  
D Singh
Keyword(s):  
Experimental Data ◽  
Perturbation Theory ◽  
Chiral Perturbation Theory ◽  
Essential Role ◽  
Heavy Baryon ◽  
Transverse Polarization ◽  
Proton Target ◽  
Chiral Perturbation ◽  
Target Asymmetry ◽  
Chiral Order

We study the reaction π + N → 2π + N within the framework of heavy-baryon chiral perturbation theory of chiral order three. We find that contributions from amplitudes of chiral order three are large and play an essential role in reproducing the experimental data. In addition, we evaluate a polarization observable (target asymmetry) for the transverse polarization of the proton target and find that the asymmetry is generally small for the reaction under consideration. PACS Nos.: 25.80.Hp, 13.75.Gx, 11.30.Rd, 11.10.Ef

scholarly journals Equivalence Between Vector Meson Dominance and Unitarised Chiral Perturbation Theory

2015 ◽  
Vol 24 (4) ◽  
pp. 289
Author(s):  
Truong Nguyen Tran ◽  
Le Viet Dung
Keyword(s):  
Perturbation Theory ◽  
Vector Meson ◽  
Chiral Perturbation Theory ◽  
Vector Meson Dominance ◽  
S Wave ◽  
Chiral Perturbation ◽  
Scalar Form Factor ◽  
Scalar Form ◽  
Standard Vector ◽  
The One

It is explicitly shown that either the approximate solution of the integral equation for the inverse of the pion form facto,r or the result of the Pad\(\text{\'e}\) approximant method of resumming the one loop Chiral Perturbation Theory (CPTH) are equivalent to the standard vector meson dominance (VMD) models, using the vector meson coupling to two pseudoscalars given by the KSRF relation. Inconsistencies between the one loop CPTH and its unitarised version (or the VMD model) are pointed out. The situation is better for the CPTH calculation of the scalar form factor and the related S-wave $\pi \pi$ scattering. The branching ratios of \(\tau \to \pi^+ \pi^0 \nu \), \(\tau \to K \pi \nu \), \(\tau \to K^+ \eta \nu\) and $\tau \to K^+ \bar{K^0} \nu\) using only two inputs as the \(\rho\) and \(K^*\) masses, or the two corresponding rms radii, agree with the experimental data. Using the same number of parameters, the corresponding one loop CPTH calculation cannot explain the $\tau$ data.

scholarly journals Taylor's Series and Dispersion Relation Analyses of the Vector Pion Form Factor and their Comparison with Perturbative and Non Perturbative Calculations

2015 ◽  
Vol 25 (1) ◽  
pp. 21
Author(s):  
Truong Nguyen Tran
Keyword(s):  
Experimental Data ◽  
Perturbation Theory ◽  
Form Factor ◽  
Dispersion Relation ◽  
Momentum Transfer ◽  
Chiral Perturbation Theory ◽  
Pion Form Factor ◽  
P Wave ◽  
Chiral Perturbation ◽  
Taylor’S Series

The first three coefficients of the Taylor's series expansion of the vevtor pion form factor as a function of the momentum transfer are evaluated using the experimental data on the pion form factor and the P-wave \(\pi\pi\) phase shifts. The real part of the form factor as a function of energy is also calculated by dispersion relation. Comparisons there results with Chiral Perturbation Theory and unitarized models are given.

scholarly journals REMARK ON PION SCATTERING LENGTHS

2009 ◽  
Vol 24 (28) ◽  
pp. 2285-2289 ◽  
Author(s):  
DEIRDRE BLACK ◽  
AMIR H. FARIBORZ ◽  
RENATA JORA ◽  
NAE WOONG PARK ◽  
JOSEPH SCHECHTER ◽  
...  
Keyword(s):  
Perturbation Theory ◽  
Chiral Perturbation Theory ◽  
Scattering Length ◽  
Linear Sigma Model ◽  
Isotopic Spin ◽  
S Wave ◽  
Tree Amplitude ◽  
Chiral Perturbation ◽  
Pion Scattering ◽  
Scattering Lengths

First it is shown that the tree amplitude for pion–pion scattering in the minimal linear sigma model has an exact expression which is proportional to a geometric series in the quantity [Formula: see text], where mB is the sigma mass which appears in the Lagrangian and is the only a priori unknown parameter in the model. This induces an infinite series for every predicted scattering length in which each term corresponds to a given order in the chiral perturbation theory counting. It is noted that, perhaps surprisingly, the pattern, though not the exact values, of chiral perturbation theory predictions for both the isotopic spin 0 and isotopic spin 2 s-wave pion–pion scattering lengths to orders p2, p4 and p6 seems to agree with this induced pattern. The values of the p8 terms are also given for comparison with a possible future chiral perturbation theory calculation. Further aspects of this approach and future directions are briefly discussed.

scholarly journals The axion-baryon coupling in SU(3) heavy baryon chiral perturbation theory

2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
Thomas Vonk ◽  
Feng-Kun Guo ◽  
Ulf-G. Meißner
Keyword(s):  
Perturbation Theory ◽  
Chiral Perturbation Theory ◽  
Heavy Baryon ◽  
Power Counting ◽  
Flavor Symmetry ◽  
Chiral Perturbation ◽  
Third Order ◽  
Stellar Objects ◽  
The Past ◽  
Dense Nuclear Matter

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.

Light front Hamiltonian for boson form of QED (1 + 1) in Pauli–Villars regularization

2019 ◽  
Vol 34 (21) ◽  
pp. 1950113
Author(s):  
V. A. Franke ◽  
M. Yu. Malyshev ◽  
S. A. Paston ◽  
E. V. Prokhvatilov ◽  
M. I. Vyazovsky
Keyword(s):  
Perturbation Theory ◽  
Chiral Perturbation Theory ◽  
Chiral Condensate ◽  
Light Front ◽  
Coupling Constants ◽  
Hamiltonian Approach ◽  
Chiral Perturbation ◽  
Dimensional Models ◽  
Villars Regularization ◽  
Ultraviolet Regularization

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.

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