Direct Photon Production at the $\psi$

Scharre, D.L. ; Alam, M.S. ; Boyarski, A. ; et al.
Phys.Rev.D 23 (1981) 43, 1981.
Inspire Record 153865 DOI 10.17182/hepdata.24079

We present results of a detailed analysis of inclusive direct photon production at the ψ(3095). The direct-photon momentum distribution for x>0.4 is presented and compared with the leading-order quantum-chromodynamic prediction. The total production rate is found to be consistent with theoretical expectations, but the observed momentum distribution is considerably softer. Results of an analysis of some inclusive properties of the hadronic system recoiling against the direct photon are presented. The mean charged-particle and Ks multiplicities are presented as functions of the invariant mass of the hadronic system. These data agree well with the corresponding mean multiplicities measured in e+e− annihilations at center-of-mass energies comparable to the invariant mass of the hadronic system.

4 data tables

TOTAL INCLUSIVE PHOTON MOMENTUM SPECTRUM. ERRORS ARE STATISTICAL ONLY.

PHOTON SPECTRUM PREDICTED FROM MEASUREMENT OF THE PI0 AND ETA DISTRIBUTIONS. ERRORS INCLUDE BOTH STATISTICAL AND RELATIVE SYSTEMATIC COMPONENTS.

INCLUSIVE PI0 MOMENTUM DISTRIBUTION. QUOTED ERRORS ARE STATISTICAL ONLY. OVERALL AND RELATIVE SYSTEMATIC ERRORS ARE LESS THAN 30 PCT AND MAY VARY SLOWLY WITH X.

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Measurement of High-energy Direct Photons in $\psi$ Decays

Abrams, G.S. ; Alam, M.S. ; Blocker, C.A. ; et al.
Phys.Rev.Lett. 44 (1980) 114, 1980.
Inspire Record 142835 DOI 10.17182/hepdata.20729

The inclusive γ and π0 momentum distributions at the ψ have been measured. Using these data and estimates of η production, it is found that (4.1 ± 0.8)% of ψ decays contain a direct photon with energy greater than 60% of the beam energy. The expected momentum distribution for direct photons calculated to lowest order in quantum chromodynamics is qualitatively different from that observed in the data.

1 data table

INCLUSIVE PHOTON AND PI0 MOMENTUM DISTRIBUTION.


RESULTS FROM DASP ON E+ E- ANNIHILATION BETWEEN 3.1-GEV AND 5.2-GEV

The DASP collaboration Brandelik, R. ; Braunschweig, W. ; Martyn, H.U. ; et al.
Z.Phys.C 1 (1979) 233-256, 1979.
Inspire Record 145403 DOI 10.17182/hepdata.16476

This paper summarizes the measurements one+e− annihilation performed by the DASP Collaboration in the energy range between 3.1 and 5.2 GeV. The following topics are covered: total cross section, production and two body decays of the narrow resonances, radiative decays of theJ/ψ and ψ′ resonances and evidence for theX(2.82), ψ′ cascade decays, inclusive η production and evidence for theF meson, semileptonic decays of charmed mesons and properties of the heavy lepton.

5 data tables

THESE DATA ON R WERE PUBLISHED IN R. BRANDELIK ET AL., PL 76B, 361 (1978), THE RECORD OF WHICH HAS TABULATED CROSS SECTIONS WITH AND WITHOUT THE TAU HEAVY LEPTON CONTRIBUTION.

OBSERVATION OF J/PSI RESONANCE.

OBSERVATION OF PSI(3700)0 RESONANCE.

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