scholarly journals CHIRAL LAGRANGIANS

2002 ◽  
Vol 17 (23) ◽  
pp. 3154-3169
Author(s):  
JOHAN BIJNENS

An overview of the field of Chiral Lagrangians is given. This includes Chiral Perturbation Theory and resummations to extend it to higher energies, applications to the muon anomalous magnetic moment, ∊′/∊ and others.

2018 ◽  
Vol 175 ◽  
pp. 06010
Author(s):  
Maarten Golterman ◽  
Kim Maltman ◽  
Santiago Peris

One of the systematic errors in some of the current lattice computations of the HVP contribution to the muon anomalous magnetic moment g – 2 is that associated with the extrapolation to the physical pion mass. We investigate this extrapolation assuming lattice pion masses in the range of 220 to 440 MeV with the help of two-loop chiral perturbation theory, and find that such an extrapolation is unlikely to lead to control of this systematic error at the 1% level. This remains true even if various proposed tricks to improve the chiral extrapolation are taken into account.


2021 ◽  
Vol 104 (11) ◽  
Author(s):  
Rubén Flores-Mendieta ◽  
Carlos Isaac García ◽  
Johann Hernández ◽  
María Anabel Trejo

1989 ◽  
Vol 04 (09) ◽  
pp. 869-876 ◽  
Author(s):  
HAI-YANG CHENG ◽  
C.Y. CHEUNG ◽  
WAI BONG YEUNG

Corrections to current-algebra analysis of K→3π decay amplitudes are calculated using the dimension-four effective chiral Lagrangians, which are uniquely determined from the integration of nontopological chiral anomalies. We find that the constant and linear terms in the ΔI = ½ amplitude are in good agreement with experiment; the previous discrepancy of 20–35% between current algebra and experiment is thus accounted for by including the higher order chiral Lagrangians. Predictions for quadratic terms are also given for both ΔI = ½ and [Formula: see text] transitions.


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.


2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Ryuichiro Kitano ◽  
Hiromasa Takaura ◽  
Shoji Hashimoto

Abstract We perform a numerical computation of the anomalous magnetic moment (g − 2) of the electron in QED by using the stochastic perturbation theory. Formulating QED on the lattice, we develop a method to calculate the coefficients of the perturbative series of g − 2 without the use of the Feynman diagrams. We demonstrate the feasibility of the method by performing a computation up to the α3 order and compare with the known results. This program provides us with a totally independent check of the results obtained by the Feynman diagrams and will be useful for the estimations of not-yet-calculated higher order values. This work provides an example of the application of the numerical stochastic perturbation theory to physical quantities, for which the external states have to be taken on-shell.


2021 ◽  
Vol 103 (1) ◽  
Author(s):  
Debajyoti Choudhury ◽  
Suvam Maharana ◽  
Vandana Sahdev ◽  
Divya Sachdeva

2002 ◽  
Vol 634 (1-2) ◽  
pp. 230-246 ◽  
Author(s):  
Giacomo Cacciapaglia ◽  
Marco Cirelli ◽  
Giampaolo Cristadoro

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