6533b825fe1ef96bd12826ea

RESEARCH PRODUCT

Triangle singularity enhancing isospin violation in ${\bar{{\rm{B}}}}_{{\rm{s}}}^{0}\to {\rm{J}}/{\rm{\psi }}{\pi }^{0}{{\rm{f}}}_{0}(980)$

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description

We perform calculations for the and reactions, showing that the first is isospin-suppressed while the second is isospin-allowed. The reaction proceeds via a triangle mechanism, with , followed by the decay K* → Kπ and a further fusion of into the or a0(980). We show that the mechanism develops a singularity around the π0 f0(980) or π0 a0(980) invariant mass of 1420 MeV, where the π0 f0 and π0 a0 decay modes are magnified and also the ratio of π0 f0 to π0 a0 production. Using experimental information for the decay, we are able to obtain absolute values for the reactions studied which fall into the experimentally accessible range. The reactions proposed and the observables evaluated, when contrasted with actual experiments, should be very valuable to obtain information on the nature of the low lying scalar mesons.