0000000000406558
AUTHOR
José Ramón Peláez Sagredo
eta ->pi(0)gamma gamma decay within a chiral unitary approach revisited
n view of the recent experimental developments on the experimental side in the η→π0γγ decay, and the fact that the Particle Data Group in the on line edition of 2007 reports sizable changes of the radiative decay widths of vector mesons used as input in the theoretical calculations of \cite{eta}, a reevaluation of the decay width of the η in this channel has been done, reducing its uncertainty by almost a factor of two. The new input of the PDG is used and invariant mass distributions and total widths are compared with the most recent results from AGS, MAMI and preliminary ones of KLOE. The agreement of the theory with the AGS and MAMI data is very good, both for the total rates as well as …
eta ->pi(0)gamma gamma decay within a chiral unitary approach
We improve the calculations of the η⃗ π0γγ decay within the context of meson chiral Lagrangians. We use a chiral unitary approach for the meson-meson interaction, thus generating the a0(980) resonance and fixing the long standing sign ambiguity on its contribution. This also allows us to calculate the loops with one vector meson exchange, thus removing a former source of uncertainty. In addition we ensure the consistency of the approach with other processes, first, by using vector meson dominance couplings normalized to agree with radiative vector meson decays and, second, by checking the consistency of the calculations with the related γγ⃗ π0η reaction. We find an η⃗ π0γγ decay width of 0.…
Meson–meson and meson–baryon interactions in a chiral non-perturbative approach
A qualitative account of the meson-meson and meson-baryon interactions using chiral Lagrangians and the inverse amplitude method in coupled channels is done. The method, imposing exact unitarity, proves to be a very useful tool to extend the information contained in the chiral Lagrangians at energies beyond the realm of applicability of chiral perturbation theory. Oset Baguena, Eulogio, Eulogio.Oset@ific.uv.es