ISSN - 00319007, EISSN - 10797114, Physical Review Letters, 2012, vol. 108, p. -
Observation of two charged bottomoniumlike resonances in Y(5S) decays
We report the observation of two narrow structures in the mass spectra of the π ±Υ(nS) (n=1, 2, 3) and π ±h b(mP) (m=1, 2) pairs that are produced in association with a single charged pion in Υ(5S) decays. The measured masses and widths of the two structures averaged over the five final states are M 1=(10607.2±2.0)MeV/c2, Γ 1=(18.4±2.4) MeV, and M 2=(10652.2±1.5)MeV/c2, Γ 2=(11. 5±2.2)MeV. The results are obtained with a 121.4fb -1 data sample collected with the Belle detector in the vicinity of the Υ(5S) resonance at the KEKB asymmetric-energy e +e - collider. © 2012 American Physical Society.