Rare Decays of Light Mesons


Book Description




Light-Meson Two-Photon Decays in Full QCD.


Book Description

We present a study of two-photon decays of light mesons, focusing on the neutral pion decay. This important process highlights the effects of the axial anomaly in QCD but has been little studied on the lattice. By applying the Lehmann-Symanzik-Zimmermann (LSZ) reduction formula, we reconstruct the electromagnetic matrix elements from three-point vector-vector Green functions calculated on 2+1-flavor isotropic clover lattices.







Investigation of Dalitz Decays


Book Description

The investigation of Dalitz decays of neutral mesons is of general interest because the electromagnetic transition form factors observed in such decays provide a possibility to obtain information about the electromagnetic properties of the mesons as well as about their internal substructures. As a matter of fact quantum electrodynamics (QED) fails a correct prediction of Dalitz decays simply because the particles of focus are not point like. For that reason the vector meson dominance model (VMD) has been developed, which still requires further experimental verification. In the picture of VMD a virtual photon can couple to a vector meson as an intermediate state. With the CB/TAPS experiment at MAMI-C in Mainz, Germany, the Dalitz decays of the eta and the pion meson were measured and the associated transition form factors could be extracted. Moreover other decay modes of the pion, eta and the omega meson were investigated in order to determine the corresponding branching ratios. Beside a short theoretical introduction into the field of interest this work presents a full description of the experimental setup and contains detailed information about all steps of the analysis.




Exotic Decays of Light Mesons


Book Description

We discuss the information one could obtain on physics beyond the minimal standard model from studies of the rare and forbidden decays of /pi//sup 0/, /eta/ and /eta//prime/. 82 refs.




Photoproduction and Decay of Light Mesons in CLAS.


Book Description

We present preliminary experimental results on photoproduction and decay of light mesons measured with CLAS setup at JLAB . This include Dalitz decay of pseudoscalar and vector mesons, radiative decay of pseudoscalar mesons as well hadronic decays of pseudoscalar and vector mesons. The collected high statistics in some of decay channels exceeds the world data by an order of magnitude and some other decay modes are observed for the first time. It is shown how the CLAS data will improve the world data on transition form factors of light mesons, Dalitz plot analyses, branching ratios of rare decay modes and other fundamental properties potentially accessible through the light meson decays.




Meson Production, Interaction And Decay - Proceedings Of The Workshop


Book Description

This workshop proceedings presents interesting lectures on the theoretical and experimental problems which may be studied using the new GeV accelerators. It provides a discussion of ongoing and planned experiments on the CELCIUS, COSY, LEAR, SATURNE and SIS accelerators as well as general descriptions of the experimental techniques applied in these experiments. There is special focus on the meson production mechanism in various reactions, meson spectroscopy and meson decay modes.




Light Meson Physics from Charm Decays at Fermilab E791


Book Description

We present recent results on light mesons based on Dalitz plot analyses of charm decays from Fermilab experiment E791. Scalar mesons are found to have large contributions to the decays studied, D[sup+][yields][pi][sup+][pi][sup+] and D[sup+], D[sub s][sup+][yields][pi][sup -][pi][sup+][pi][sup+]. From the K[pi][pi] final state, we find good evidence for the existence of the light and broad k meson and we measure its mass and width. We also discuss recently published results on the 3[pi] final states, especially the measurement of the f[sub 0] parameters and the evidence for the[sigma] meson from D[sup+][yields][sigma][pi][sup+]. These results demonstrate the importance of charm decays as a new environment for the study of light meson physics.