Date

SEARCH FOR EXCLUSIVE J / psi PRODUCTION

Chiang, I.H. ; Johnson, R.A. ; Kwan, B.P. ; et al.
Phys.Rev.D 34 (1986) 1619, 1986.
Inspire Record 228262 DOI 10.17182/hepdata.23503

We have searched for exclusive hadronic J/ψ production by looking for narrow resonances in the e+e− mass spectrum of the reaction π−p→e+e−n. No events were observed in the region around 3.1 GeV/c2. The cross section for the reaction π−p→J/ψ n at 13 GeV/c is no more than 103 pb at the 90% confidence level.

1 data table

Corrected cross section based on 7.4 pct branching ratio.


EXPERIMENTAL SEARCH FOR NARROW RESONANCES IN THE REACTION PI- P ---> GAMMA GAMMA N AT 13-GEV/C

Chiang, I.H. ; Johnson, R.A. ; Kwan, B.P. ; et al.
Phys.Lett.B 140 (1984) 145-148, 1984.
Inspire Record 206508 DOI 10.17182/hepdata.30553

Using a double arm electromagnetic calorimeter we have searched for narrow states produced in the exclusive reaction π − p→γγn at 13 GeV/c. No enhancements were observed in the mass range 2.0–4.0 GeV/c 2 . For example, the 90% confidence limit on η c production is σ ( π − p→ η c n)× B ( η c → γγ ) < 44 pb.

1 data table

UPPER LIMIT (90 PCT CL) FOR SIG*BR(ETA/C --> 2 GAMMA).


Measurements of the Photon Total Cross-Section on Protons from 18 GeV to 185 GeV

Caldwell, David O. ; Cumalat, John P. ; Eisner, A.M. ; et al.
Phys.Rev.Lett. 40 (1978) 1222, 1978.
Inspire Record 129172 DOI 10.17182/hepdata.3355

The photon total cross section on protons has been measured with high precision in the Fermilab tagged-photon beam for photon energies from 18 to 185 GeV. The cross section decreases to a broad minimum near 40 GeV, and then rises by about 4 μb over the remainder of the range. A ρ+ω+ϕ vector-dominance model (normalized to low-energy data) falls below the high-energy results by 2 to 6 μb, suggesting a contribution from charm-anticharm states.

2 data tables

No description provided.

No description provided.