https://doi.org/10.1140/epja/i2018-12450-5
Regular Article - Theoretical Physics
Triangle singularities in 
and 
1
Departamento de Física Teórica and IFIC, Centro Mixto Universidad de Valencia-CSIC Institutos de Investigación de Paterna, Aptdo.22085, 46071, Valencia, Spain
2
Departament de Física Quàntica i Astrofísica and Institut de Ciències del Cosmos, Universitat de Barcelona, Martí i Franquès 1, 08028, Barcelona, Spain
* e-mail: shuntaro.sakai@ific.uv.es
Received:
18
September
2017
Accepted:
20
December
2017
Published online:
29
January
2018
We study the appearance of structures in the decay of the 
into 
and 
final states by forming invariant mass distributions of 
and 
pairs, respectively. The structure in the distribution is associated to the kinematical triangle singularity that appears when the 
(
) decay process is followed by the decay of the 
into 
and the subsequent rescattering of the 
(
) pair forming the 
( 
resonance. We find this type of non-resonant peaks at 2850MeV in the invariant mass of 
pairs from 
decays and around 3000MeV in the invariant mass of pairs from 
decays. By employing the measured branching ratios of the and decays, we predict the branching ratios for the processes 
into 
and , in the vicinity of the triangle singularity peak, to be about 
and 
, respectively. The observation of this reaction would also give extra support to the molecular picture of the and .
© SIF, Springer-Verlag GmbH Germany, part of Springer Nature, 2018
