ISSN - 00319007, EISSN - 10797114, Physical Review Letters, 2010, vol. 104, p. -
Measurements of hc(P11) in ψ′ Decays
We present measurements of the charmonium state hc(P11) made with 106×106 ψ′ events collected by BESIII at BEPCII. Clear signals are observed for ψ′→π0hc with and without the subsequent radiative decay hc→γηc. First measurements of the absolute branching ratios B(ψ′→π0hc)=(8. 4±1.3±1.0)×10-4 and B(hc→γηc)=(54. 3±6.7±5.2)% are presented. A statistics-limited determination of the previously unmeasured hc width leads to an upper limit Γ(hc)<1. 44MeV (90% confidence). Measurements of M(hc)=3525.40±0.13±0. 18MeV/c2 and B(ψ′→π0hc) ×B(hc→γηc)=(4.58±0.40±0.50)×10 -4 are consistent with previous results. © 2010 The American Physical Society.