We report the first observation of Bs0→J/ψf0(980) and first
evidence for Bs0→J/ψf0(1370), which are CP eigenstate decay modes.
These results are obtained from 121.4fb−1 of data collected at
the Υ(5S) resonance with the Belle detector at the KEKB e+e−
collider. We measure the branching fractions B(Bs0→J/ψf0(980);f0(980)→π+π−)=(1.16−0.19+0.31(stat.)−0.17+0.15(syst.)−0.18+0.26(NBs(∗)Bˉs(∗)))×10−4 with a significance of 8.4σ, and
B(Bs0→J/ψf0(1370);f0(1370)→π+π−)=(0.34−0.14+0.11(stat.)−0.02+0.03(syst.)−0.05+0.08(NBs(∗)Bˉs(∗)))×10−4 with a significance of 4.2σ. The last error
listed is due to uncertainty in the number of produced Bs(∗)Bˉs(∗) pairs.Comment: 5 pages, 2 figures, 2 tables, published in PR