%0 Journal Article
%T Extended chiral Khuri-Treiman formalism for eta -> 3 pi and the role of the a(0)(980), f(0)(980) resonances
%A Albaladejo, M.
%A Moussallam, B.
%J European Physical Journal C
%D 2017
%V 77
%N 8
%I Springer
%@ 1434-6044
%G English
%F Albaladejo+Moussallam2017
%O WOS:000406687400002
%O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=3229), last updated on Mon, 21 Aug 2017 15:00:24 +0000
%X Recent experiments on eta -> 3 pi decays have provided an extremely precise knowledge of the amplitudes across the Dalitz region which represent stringent constraints on theoretical descriptions. We reconsider an approach in which the low-energy chiral expansion is assumed to be optimally convergent in an unphysical region surrounding the Adler zero, and the amplitude in the physical region is uniquely deduced by an analyticity-based extrapolation using the Khuri-Treiman dispersive formalism. We present an extension of the usual formalism which implements the leading inelastic effects from the K (K) over bar channel in the final-state pi pi interaction as well as in the initial-state eta pi interaction. The constructed amplitude has an enlarged region of validity and accounts in a realistic way for the influence of the two light scalar resonances f(0)(980) and a(0)(980) in the dispersive integrals. It is shown that the effect of these resonances in the low-energy region of the eta -> 3 pi decay is not negligible, in particular for the 3 pi(0) mode, and improves the description of the energy variation across the Dalitz plot. Some remarks are made on the scale dependence and the value of the double quark mass ratio Q.
%R 10.1140/epjc/s10052-017-5052-x
%U http://arxiv.org/abs/1702.04931
%U https://doi.org/10.1140/epjc/s10052-017-5052-x
%P 508 - 23pp