TY  - JOUR
AU  - Oset, E.
AU  - Roca, L.
PY  - 2018
DA  - 2018//
TI  - Triangle mechanism in tau -> f(1)(1285)pi nu(tau) decay
T2  - Phys. Lett. B
JO  - Physics Letters B
SP  - 332
EP  - 338
VL  - 782
PB  - Elsevier Science Bv
AB  - 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.
SN  - 0370-2693
UR  - http://arxiv.org/abs/1803.07807
UR  - https://doi.org/10.1016/j.physletb.2018.05.056
DO  - 10.1016/j.physletb.2018.05.056
LA  - English
N1  - WOS:000438486900054
ID  - Oset+Roca2018
ER  -