%0 Journal Article
%T Triangle mechanism in tau -> f(1)(1285)pi nu(tau) decay
%A Oset, E.
%A Roca, L.
%J Physics Letters B
%D 2018
%V 782
%I Elsevier Science Bv
%@ 0370-2693
%G English
%F Oset+Roca2018
%O WOS:000438486900054
%O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=3663), last updated on Tue, 31 Jul 2018 11:55:56 +0000
%X We show that the tau(-) decay into f(1)(1285) pi(-)nu(tau) is dominated by a triangle loop mechanism with K*, (K) over bar* and K( or (K) over bar) as internal lines, which manifests a strong enhancement reminiscent of a nearby singularity present in the narrow K* limit and the near (K) over bar* K* threshold of the internal K* propagators. The f1(1285) is then produced by its coupling to the K* (K) over bar and (K) over bar* K which is obtained from a previous model where this resonance was dynamically generated as a molecular K* (K) over bar (or (K) over bar* K) state using the techniques of the chiral unitary approach. We make predictions for the f(1)pi mass distribution which significantly deviates from the phase-space shape, due to the distortion caused by the triangle mechanism and the K* (K) over bar threshold. We find a good agreement with the experimental value within uncertainties for the integrated partial decay width, which is a clear indication of the importance of the triangle mechanism in this decay and supports the dynamical origin of the f(1)(1285) as a K* (K) over bar and (K) over bar* K molecular state.
%R 10.1016/j.physletb.2018.05.056
%U http://arxiv.org/abs/1803.07807
%U https://doi.org/10.1016/j.physletb.2018.05.056
%P 332-338