Cosme, G.
E+ E- --> ETA GAMMA
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rivet Analysis
Measurement of the eta and eta' transition form factors at q**2 = 112-GeV**2.

The BaBar collaboration Aubert, Bernard ; Barate, R. ; Bona, M. ; et al.
Phys.Rev.D 74 (2006) 012002, 2006.
Inspire Record 716277 DOI 10.17182/hepdata.22085

We report a study of the processes e+e- -> eta gamma and e+e- -> etaprime gamma at a center-of-mass energy of 10.58 GeV, using a 232 fb^-1 data sample collected with the BABAR detector at the PEP-II collider at SLAC. We observe 20+6-5 eta gamma and 50+8-7 etaprime gamma events over small backgrounds, and measure the cross sections sigma(e+e- -> eta gamma) =4.5+1.2-1.1(stat)+-0.3(sys) fb and sigma(e+e- -> etaprime gamma)=5.4+-0.8(stat)+-0.3(sys) fb. The corresponding transition form factors at q^2 = 112 GeV^2 are q^2|F_eta(q^2)|=0.229+-0.030+-0.008 GeV, and q^2|F_etaprime(q^2)|=0.251+-0.019+-0.008 GeV, respectively.

3 data tables
Table 1

Measured cross sections.

Table 2

Undressed cross sections calculated by applying a 7.5 +- 0.2 PCT correction for vacuum polarization.

Table 3

Transition form factors at Q**2 = 112 GeV**2.


New Measurements with the Orsay electron-Positron Storage Ring of the Radiative Decay Modes of the phi-Meson

Cosme, G. ; Courau, A. ; Dudelzak, B. ; et al.
Phys.Lett.B 63 (1976) 352-356, 1976.
Inspire Record 99833 DOI 10.17182/hepdata.27640

The radiative decay models of the φ-meson have been studied: e + e − → φ → ηγ →3 γ ; e + e − → φ → π o γ →3 γ . Cross sections σ φ → ηγ →3 γ and σ φ → π o γ →3 γ have been measured at five energies in the φ-meson energy region and clearly show the φ-resonance in the ηγ → 3 γ mode as well as in the π o γ → 3 γ mode. From a Breit-Wigner fit to the experimental data the values of the branching ratios are deduced: B φ → ηγ = (1.5 ± 0.4) × 10 −2 ; B φ → π o γ = (1.4 ± 0.5) × 10 −3 .

1 data table
Table 1

REMOVING RADIATIVE CORRECTIONS, THE PHI PEAK CROSS SECTIONS ARE 66 NB +- 25 PCT <ETA GAMMA> AND 6.5 NB +- 30 PCT <PI0 GAMMA>.