literature
Literature
Authors
Jobs
Seminars
Conferences
DataBETA

The Decay eta(c) ---> gamma gamma: A Test for potential models

Jan 25, 1994
7 pages
Published in:
  • Phys.Rev.D 51 (1995) 141-146
e-Print:
DOI:
View in:
pdf
reference search32 citations

Citations per year

1994200120082015202101234
Abstract: (CERN)
We use a simple perturbation theory argument and measurements of charmonium leptonic widths Γ(ψNS→e +e −)\Gamma (\psi_{NS} \rightarrow e~+e~-) to estimate the ratio \mbox{R∘≡∣Ψηc1S(0)∣ 2/∣Ψψ1S(0)∣ 2R_\circ \equiv {\vert \Psi _{\eta_{c1S}}(0) \vert}~2 /{\vert\Psi_{\psi_{1 S}}(0)\vert}~2} in the general context of non- relativistic potential models. We obtain R∘=1.4±0.1R_\circ = 1.4 \pm 0.1. We then apply well known potential model formulas, which include lowest order QCD corrections, to find Γ(ηc→γγ)/Γ(ψ1S→e +e −)≈2.2±0.2\Gamma (\eta_c \rightarrow \gamma \gamma )/\Gamma (\psi_{1S} \rightarrow e~+e~-) \approx 2.2\pm 0.2. The central value for Γ(ψ1S→e +e −)\Gamma (\psi_{1S} \rightarrow e~+ e~-) in the 1992 Particle Data Tables then leads to a prediction Γ(ηc→γγ)≈11.8±0.8\Gamma (\eta_c \rightarrow \gamma \gamma )\approx 11.8\pm 0.8 keV. This prediction is in good agreement with a recent measurement by the ARGUS collaboration, is consistent with a recent measurement by the L3 collaboration but is significantly higher than several earlier measurements and than previous theoretical estimates, which usually assume R∘=1R_\circ =1. The correction to R∘=1R_\circ =1 is estimated to be smaller but nonnegligible for the bbˉb\bar b system. Using the current central measurement for Γ(Υ1S→e +e −)\Gamma (\Upsilon_{1S}\rightarrow e~+e~-) we find Γ(ηb→γγ)≈0.58±0.03\Gamma (\eta_b\rightarrow \gamma \gamma )\approx 0.58\pm 0.03 keV.
  • Upsilon(9460): leptonic decay
  • leptonic decay: Upsilon(9460)
  • Upsilon(9460): width
  • potential: nonrelativistic
  • perturbation theory
  • numerical calculations: interpretation of experiments
  • Upsilon(9460) --> positron electron
  • eta/c(2980): radiative decay
  • radiative decay: eta/c(2980)
  • eta/c(2980): width