Evidence for Direct $\gamma$ Production at Large $x$ in $\psi$ (3100) Decay

Ronan, M.T. ; Trippe, T.G. ; Barbaro-Galtieri, A. ; et al.
Phys.Rev.Lett. 44 (1980) 367, 1980.
Inspire Record 142946 DOI 10.17182/hepdata.20700

The inclusive γ and π0 momentum spectra from ψ(3100) decay have been measured in e+e− annihilation at SPEAR. When the γ spectrum is compared with that expected from π0 decay, an excess of high-momentum γ's is observed. This excess is compared with that predicted by quantum chromodynamics for the decay of the ψ into a γ and two gluons.

4 data tables

THE STATISTICAL AND SYSTEMATIC ERRORS ARE GIVEN SEPARATELY AS WELL AS COMBINED IN QUADRATURE FOR THE QUOTED TOTAL ERROR.

THE STATISTICAL AND SYSTEMATIC ERRORS ARE GIVEN SEPARATELY AS WELL AS COMBINED IN QUADRATURE FOR THE QUOTED TOTAL ERROR. SYSTEMATIC ERROR IS 17 PCT.

QUOTED ERRORS ARE STATISTICAL. SYSTEMATIC ERROR IS 20 PCT. ONLY HALF THE SUM OF THE PI+ AND PI- CROSS SECTIONS IS PLOTTED IN THE FIGURE IN THE JOURNAL.

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Inclusive $\gamma$ and $\pi^0$ Production in $e^+ e^-$ Annihilation

Scharre, D.L. ; Fong, A. ; Pun, T. ; et al.
Phys.Rev.Lett. 41 (1978) 1005, 1978.
Inspire Record 130859 DOI 10.17182/hepdata.20888

We have measured inclusive γ and π0 production in multiprong events produced by e+e− annihilation in the center-of-mass energy range 4.9 to 7.4 GeV. We find the π0 inclusive cross section to be consistent in shape and normalization with half the charged-π cross section between x=0.15 and 0.60, with an integrated inclusive cross-section ratio of σ(π0)|σ(π+)+σ(π−)|=0.47±0.10.

1 data table

NUMERICAL VALUES OF DATA FROM THIS EXPERIMENT HAVE NOT BEEN KEPT (M. L. PERL, PRIV COMM, 3 MAY 1979).