Adam, J.
nucl-ex
Cross Section
[23.742]
Max results
Sort by Reverse order

Showing 3 of 3 results

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
Table 1

Data supplied by V. Paolone.

Table 2

Cross section data using Bethe-Heitler event normalization.

Table 3

Cross section data using the Beam Gamma Monitor normalization.


Production of $J / \psi$ via $\psi^{\prime}$ and $X$ Decay in 300-GeV/c Proton and $\pi^{\pm}$ Nucleon Interactions

The E705 collaboration Antoniazzi, L. ; Arenton, M. ; Cao, Z. ; et al.
Phys.Rev.Lett. 70 (1993) 383-386, 1993.
Inspire Record 336204 DOI 10.17182/hepdata.19754

The production of the χ1 and χ2 states of charmonium has been observed in 300 GeV/c π±N and pN interactions. The fraction of the total inclusive J/ψ production due to radiative χ decay has been determined to be 0.40±0.04, 0.37±0.03, and 0.30±0.04 for the π+, π−, and proton data, respectively. Total cross sections have been obtained of 131±18±14 and 188±30±21 nb/nucleon in the 300 GeV/c π−N interactions for χ1 and χ2 production. By measuring the contributions to the J/ψ production due to both ψ’ and radiative χ decay, the cross sections for direct J/ψ production have been determined to be 97±14, 102±14, and 89±12 nb/nucleon for π+, π−, and protons, respectively.

8 data tables
Table 1

Fractions of total J/PSI production due to radiative CHI1 and CHI2 decays.

Table 2

Fractions of total J/PSI production due to radiative CHI1 and CHI2 decays.

Table 3

Fractions of total J/PSI production due to radiative CHI1 and CHI2 decays.

More…

Measurement of Lepton and Pion Pair Production in Photon - Photon Collisions at Dci

Courau, A. ; Falvard, A. ; Haissinski, J. ; et al.
Phys.Lett.B 96 (1980) 402-406, 1980.
Inspire Record 153776 DOI 10.17182/hepdata.49087

We report a photon-photon experiment performed at the Orsay storage rings. 300e + e − , μ + μ − and π + π − pairs produced with low invariant masses have been observed. For each event, one or both protons have been tagged at a very small angle. The γγ→μ + μ − and γγ→π + π − cross-sections have been measured near threshold, the γγ→e + e − process being used as a normalization. The observed invariant mass distribution is compared to theoretical calculations for each of the three processes. The μ + μ − data are in good agreement with QED predictions. The π + π − cross-section, in our experimental acceptance, is somewhat larger than the one expected from the Born terms only.

1 data table
Table 1

EACH BEAM ENERGY VARIED BETWEEN 750 MEV AND 1 GEV.