ISSN - 00319007, EISSN - 10797114, Physical Review Letters, 2012, vol. 108, p. -
First observation of η(1405) decays into f 0(980)π0
The decays J/ψ→γπ +π -π0 and J/ψ→γπ0π0π0 are analyzed using a sample of 225×106 J/ψ events collected with the BESIII detector. The decay of η(1405)→f 0(980)π0 with a large isospin violation is observed for the first time. The width of the f 0(980) observed in the dipion mass spectra is anomalously narrower than the world average. Decay rates for three-pion decays of the η ′ are also measured precisely. © 2012 American Physical Society.