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Related papers: Extracting the chiral anomaly from gamma pi --> pi…

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A geometrical interpretation of the consistent and covariant chiral anomaly is done in the space-time respective Hamiltonian framework.

High Energy Physics - Theory · Physics 2009-10-31 C. Ekstrand

The QED hadronic vacuum polarization function plays an important role in the determination of precision electroweak observables and of the anomalous magnetic moment of the muon. These contributions have been computed from data, by means of…

High Energy Physics - Phenomenology · Physics 2023-11-14 Nina M. Coyle , Carlos E. M. Wagner

In a recent preprint Cheon and Cheoun have derived from a chiral model an additional term, not usually appearing in the standard matrix element for radiative muon capture. Using that term they generate a large correction to the RMC spectrum…

Nuclear Theory · Physics 2007-05-23 Harold W. Fearing , TRIUMF

Differential cross sections for elastic scattering of 21.5 MeV positive and negative pions by Si, Ca, Ni and Zr have been measured as part of a study of the pion-nucleus potential across threshold. The `anomalous' repulsion in the s-wave…

We derive the vertices of five-meson and seven-meson anomaly processes from the four dimensional expansion form of Wess-Zumino term. Using these vertices we calculate the amplitude, both the finite part and divergent part, of {$K^+ K^-…

High Energy Physics - Phenomenology · Physics 2008-02-03 H. H. Shih , Y. C. Lin

We compute, in the framework of the fluid/gravity correspondence, the transport coefficients of a relativistic fluid affected by chiral and gauge-gravitational anomalies, including external electromagnetic fields. The computation is…

High Energy Physics - Theory · Physics 2015-06-15 Eugenio Megias , Francisco Pena-Benitez

One feature of the chiral anomaly, analyzed in a perturbative framework, is the appearance of massless poles which account for it. They are identified by a spectral analysis of the anomaly graph and are usually interpreted as being of an…

High Energy Physics - Phenomenology · Physics 2009-12-15 Roberta Armillis , Claudio Coriano , Luigi Delle Rose

The neutron-neutron scattering length a_nn provides a sensitive probe of charge-symmetry breaking in the strong interaction. Here we summarize our recent efforts to use chiral perturbation theory in order to systematically relate a_nn to…

Nuclear Theory · Physics 2009-04-17 A. Gardestig , D. R. Phillips

We comment on the theoretical uncertainties involved in estimating the hadronic effects on the light-by-light scattering contribution to the anomalous magnetic moment of the muon, especially based on the analysis and results of T.…

High Energy Physics - Phenomenology · Physics 2009-10-22 Martin B. Einhorn

We analyze the pion transition form factor using dispersion theory. We calculate the singly-virtual form factor in the time-like region based on data for the $e^+e^-\to 3\pi$ cross section, generalizing previous studies on…

High Energy Physics - Phenomenology · Physics 2014-12-19 Martin Hoferichter , Bastian Kubis , Stefan Leupold , Franz Niecknig , Sebastian P. Schneider

We investigate the in-medium modification of the charmonium break-up processes due to the Mott effect for light (pi) and open-charm (D, D*) mesons at the chiral/deconfinement phase transition. A model calculation for the process J/Psi + pi…

Nuclear Theory · Physics 2009-11-06 Gerhard R. G. Burau , David B. Blaschke , Yuri L. Kalinovsky

We investigate on the plane the axial anomaly for euclidean Dirac fermions in the presence of a background Aharonov--Bohm gauge potential. The non perturbative analysis depends on the self--adjoint extensions of the Dirac operator and the…

High Energy Physics - Theory · Physics 2009-10-28 P. Giacconi , S. Ouvry , R. Soldati

Numerous channels of the cross section e+e- --> hadrons have been measured by the BABAR experiment using the ISR method. For the pi+pi-(gamma) and K+K-(gamma) channels, BABAR has pioneered the method based on the ratio between the hadronic…

High Energy Physics - Experiment · Physics 2014-07-18 B. Malaescu

Our original suggestion to investigate exclusive $\pi^0$ electroproduction as a method for extracting the tensor charge, transversity, and other quantities related to chiral odd generalized parton distributions from cross section and…

High Energy Physics - Phenomenology · Physics 2015-06-17 Gary R. Goldstein , Simonetta Liuti , J. Osvaldo Gonzalez Hernandez

We construct a physically motivated model for the isospin-one non-strange vacuum polarization function Pi(Q^2) based on a spectral function given by vector-channel OPAL data from hadronic tau decays for energies below the tau mass and a…

High Energy Physics - Lattice · Physics 2015-06-17 Maarten Golterman , Kim Maltman , Santiago Peris

Starting from the Chiral Perturbation Theory Lagrangian, but keeping different masses for the charged and neutral mesons, and using a previously developed non-perturbative unitary scheme that generates the lightest meson-meson resonances,…

High Energy Physics - Phenomenology · Physics 2009-10-31 J. A. Oller , E. Oset , J. R. Pelaez

We discuss chiral theories of constituent quarks interacting with bosons at high temperatures. In the chirally symmetric phase we demonstrate by applying functional methods the presence of effective anomalous couplings for e.g. $\pi \sigma…

High Energy Physics - Phenomenology · Physics 2009-10-28 R. Baier , M. Dirks , O. Kober

We evaluate the contributions of $(\pi^0\pi^0, \pi^0\eta, \eta\eta)\gamma$ exclusive channels to the dispersion integral of the leading order HVP of the muon anomalous magnetic moment. These channels are included in some way in previous…

High Energy Physics - Phenomenology · Physics 2022-11-09 J. L. Gutiérrez-Santiago , G. López-Castro

Infra-red properties of the triangle anomaly and the ``anomaly pole'' are elaborated and applied to the study of high-energy scattering in QCD, when the gauge symmetry is partially broken to SU(2). It is shown that the chiral flavor anomaly…

High Energy Physics - Phenomenology · Physics 2009-11-07 Alan R. White

The gamma -> 3 pi form factor was calculated in a simple-minded constituent model with a constant quark mass parameter, as well as in the Schwinger-Dyson approach. The comparison of these and various other theoretical results on this…

High Energy Physics - Phenomenology · Physics 2007-05-23 Dubravko Klabucar , Bojan Bistrovic