Photon and light meson production in hadronic Z0 decays.

The OPAL collaboration Ackerstaff, K. ; Alexander, G. ; Allison, John ; et al.
Eur.Phys.J.C 5 (1998) 411-437, 1998.
Inspire Record 470419 DOI 10.17182/hepdata.49498

The inclusive production rates and differential cross-sections of photons and mesons with a final state containing photons have been measured with the OPAL detector at LEP. The light mesons covered by the measurements are the \pi^0, \eta, \rho(770)+-, \omega(782), \eta'(958) and a_0(980)+-. The particle multiplicities per hadronic Z^0 decay, extrapolated to the full energy range, are: <n_\gamma> = 20.97 +/- 0.02 +/- 1.15, <n_\pi^0> = 9.55 +/- 0.06 +/- 0.75, <n_\eta> = 0.97 +/- 0.03 +/- 0.11, <n_\rho^+-> = 2.40 +/- 0.06 +/- 0.43, <n_\omega> = 1.04 +/- 0.04 +/- 0.14, <n_\eta> = 0.14 +/- 0.01 +/- 0.02, <n_a_0+-> = 0.27 +/- 0.04 +/- 0.10. where the first errors are statistical and the second systematic. In general, the results are in agreement with the predictions of the JETSET and HERWIG Monte Carlo models.

15 data tables

Particle multiplicities per hadronic decay extrapolated to the full energy range.

Photon fragmentation function.

Photon fragmentation function.

More…

Inclusive $\gamma$ and $\pi^0$ Production in $e^+ e^-$ Annihilation at 14-{GeV}, 22-{GeV}, and 34-{GeV} Center-of-mass Energy

The CELLO collaboration Behrend, H.J. ; Fenner, H. ; Schachter, M.J. ; et al.
Z.Phys.C 20 (1983) 207, 1983.
Inspire Record 191415 DOI 10.17182/hepdata.16318

We have measured the scale invariant inclusive photon and π0 cross sections atW=14, 22 and 34 GeV. A comparison with π± data shows no significant difference between neutral and charged pion production. Comparing the integrated cross sections in thex range 0.15<x<1.0 we observe a considerable decrease from 14 GeV to 34 GeV with a statistical significance of 1.5 standard deviations. This is compatible with the expectations for scaling violations from QCD.

8 data tables

NUMERICAL VALUES OF DATA SUPPLIED BY H. OBERLACK.

NUMERICAL VALUES OF DATA SUPPLIED BY H. OBERLACK.

NUMERICAL VALUES OF DATA SUPPLIED BY H. OBERLACK.

More…

Measurement of Inclusive $\gamma$ and $\pi^0$ Spectra and a Comparison of the Neutral and Charged Components in Hadronic Events in $e^+ e^-$ Annihilation at 34-{GeV}

The CELLO collaboration Behrend, H.J. ; Chen, C. ; Fenner, H. ; et al.
Z.Phys.C 14 (1982) 189, 1982.
Inspire Record 177212 DOI 10.17182/hepdata.16411

The photonic part of multihadronice+e− annihilation events has been analyzed at a c.m. energy of 34 GeV. The photonic energy fraction per event is determined to befγ=0.251±0.003 (stat.) ±0.04 (syste.). The neutral and charged components of the events are analyzed separately revealing close similarity in thrust axis directions and momentum distributions in agreement with the hypothesis that most photons result from π0 decay. π0's are reconstructed separately and used to determine the inclusive cross section. Comparing these cross sections with lower energy data from SPEAR we find some indication for scaling violation.

2 data tables

No description provided.

No description provided.