%0 Journal Article
%T Towards an improved understanding of eta -> gamma*gamma *
%A Holz, S.
%A Plenter, J.
%A Xiao, C. W.
%A Dato, T.
%A Hanhart, C.
%A Kubis, B.
%A Meissner, U. G.
%A Wirzba, A.
%J European Physical Journal C
%D 2021
%V 81
%N 11
%I Springer
%@ 1434-6044
%G English
%F Holz_etal2021
%O WOS:000718113500001
%O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=5024), last updated on Tue, 23 Nov 2021 09:46:12 +0000
%X We argue that high-quality data on the reaction e(+)e(-) -> pi(+) pi(-) eta will allow one to determine the doubly-virtual form factor eta -> gamma*gamma* in a model-independent way with controlled accuracy. This is an important step towards a reliable evaluation of the hadronic light-by-light scattering contribution to the anomalous magnetic moment of themuon. When analyzing the existing data for e(+) e(-) -> pi(+) pi(-) eta for total energies squared k(2) > 1GeV(2), we demonstrate that the effect of the a(2) meson provides a natural breaking mechanism for the commonly employed factorization ansatz in the doubly-virtual form factor F-eta gamma*gamma* (q(2), k(2)). However, better data are needed to draw firm conclusions.
%R 10.1140/epjc/s10052-021-09661-0
%U https://arxiv.org/abs/1509.02194
%U https://doi.org/10.1140/epjc/s10052-021-09661-0
%P 1002-15pp