Production of charmonium states in pi- Be collisions at 515-GeV/c

The E672-E706 collaboration Koreshev, V. ; Jesik, R. ; Mendez, H. ; et al.
Phys.Rev.Lett. 77 (1996) 4294-4297, 1996.
Inspire Record 419626 DOI 10.17182/hepdata.42234

We report on χc1 and χc2 production in the Feynman-x range 0.1<xF<0.8 in 515GeV/c π−Be collisions. The χc states are observed via their radiative decays into J/ψ's. The resulting photons are detected either as showers in the electromagnetic calorimeter or after conversion in the target as e+e− pairs in the tracking system. The fraction of J/ψ production due to χc1 and χc2 decays is 0.443±0.041±0.035. The ratio of the χc1 to χc2 cross section is 0.57±0.18±0.06. Our results on J/ψ, ψ(2S), and χc production indicate that 0.454±0.044±0.042 of J/ψ's are produced directly.

3 data tables

No description provided.

Cross section for the direct J/PSI production.

No description provided.


A Measurement of Elastic $J / \psi$ Photoproduction Cross Section at Fermilab E687

The E687 collaboration Frabetti, P.L. ; Paolone, V.S. ; Yager, P.M. ; et al.
Phys.Lett.B 316 (1993) 197-206, 1993.
Inspire Record 359356 DOI 10.17182/hepdata.28834

Measurements of elastic photoproduction cross sections for the J / ψ meson from 100 GeV to 375 GeV are presented. The results indicate that the cross section increases slowly in this range. The shape of the energy dependence agrees well with the photon-gluon fusion model prediction.

3 data tables

Data supplied by V. Paolone.

Cross section data using Bethe-Heitler event normalization.

Cross section data using the Beam Gamma Monitor normalization.