English

Measurements of h_c(^1P_1) in psi' Decays

High Energy Physics - Experiment 2012-08-27 v2

Abstract

We present measurements of the charmonium state hc(1P1)h_c(^1P_1) made with 106M ψ\psi' events collected by BESIII at BEPCII. Clear signals are observed for ψπ0hc\psi'\to\pi^0 h_c with and without the subsequent radiative decay hcγηch_c\to\gamma\eta_c. First measurements of the absolute branching ratios B(ψπ0hc)=(8.4±1.3±1.0)×104\mathcal{B}(\psi' \to\pi^0 h_c) = (8.4 \pm 1.3 \pm 1.0) \times 10^{-4} and B(hcγηc)=(54.3±6.7±5.2)\mathcal{B}(h_c \to \gamma \eta_c) = (54.3 \pm 6.7 \pm5.2)% are presented. A statistics-limited determination of the previously unmeasured hch_c width leads to an upper limit Γ(hc)<1.44\Gamma(h_c)<1.44 MeV (90% confidence). Measurements of M(hc)=3525.40±0.13±0.18M(h_c) = 3525.40 \pm 0.13 \pm 0.18 MeV/c2c^2 and B(ψπ0hc)×B(hcγηc)=(4.58±0.40±0.50)×104\mathcal{B}(\psi'\to \pi^0 h_c) \times \mathcal{B}(h_c \to \gamma\eta_c) = (4.58 \pm 0.40 \pm 0.50) \times 10^{-4} are consistent with previous results.

Keywords

Cite

@article{arxiv.1002.0501,
  title  = {Measurements of h_c(^1P_1) in psi' Decays},
  author = {The BESIII Collaboration},
  journal= {arXiv preprint arXiv:1002.0501},
  year   = {2012}
}

Comments

5 pages, 1 figure, accepted for publication in Physical Review Letters