Hadroproduction of the chi1 and chi2 states of charmonium in 800-GeV/c proton silicon interactions.

The E771 collaboration Alexopoulos, T. ; Antoniazzi, L. ; Arenton, M. ; et al.
Phys.Rev.D 62 (2000) 032006, 2000.
Inspire Record 504991 DOI 10.17182/hepdata.41516

The cross sections for the hadroproduction of the Chi1 and Chi2 states of charmonium in proton-silicon collisions at sqrt{s}=38.8 GeV have been measured in Fermilab fixed target Experiment 771. The Chi states were observed via their radiative decay to J/psi+gamma, where the photon converted to e+e- in the material of the spectrometer. The measured values for the Chi1 and Chi2 cross sections for x_F>0 are 263+-69(stat)+-32(syst) and 498+-143(stat)+-67(syst) nb per nucleon respectively. The resulting sigma(Chi1}/sigma(Chi2) ratio of 0.53+-0.20(stat)+-0.07(syst), although somewhat larger than most theoretical expectations, can be accomodated by the latest theoretical estimates.

1 data table

No description provided.


A measurement of the b anti-b cross section in 800-GeV/c proton silicon interactions.

The E771 collaboration Alexopoulos, T. ; Antoniazzi, L. ; Arenton, M. ; et al.
Phys.Rev.Lett. 82 (1999) 41-44, 1999.
Inspire Record 447430 DOI 10.17182/hepdata.42183

The cross section for bb¯ production in 800GeV/c pN interactions has been measured in Fermilab experiment E771 to be 43−17+27(stat)−7+7(syst)nb per nucleon from the observation of events in which both the b and the b¯ decay semimuonically or a B decays into a J/ψ followed by J/ψ→μ+μ−.

1 data table

No description provided.


Measurement of J / psi, psi-prime and upsilon total cross-sections in 800-GeV/c p - Si interactions

The E771 collaboration Alexopoulos, T ; Antoniazzi, L ; Arenton, M ; et al.
Phys.Lett.B 374 (1996) 271-276, 1996.
Inspire Record 400873 DOI 10.17182/hepdata.42316

We report on the analysis of Charmonium and Bottomium states produced in p-Si interactions at s =38.7 GeV . The data have been collected with the open geometry spectrometer of the E771 Experiment at the FNAL High Intensity Lab. J ψ , ψ′ and γ total cross sections as well as the ratio B(ψ′ → μμ)σ(ψ′) (B( J ψ → μμ)σ( J ψ )) have been measured. Results are compared with theoretical predictions and with results at other energies.

3 data tables

The total inclusive cross section per nucleon has been evaluated assuming an atomic weight dependence of A**POWER with POWER = 0.920 +- 0.008.

combined UPSI(1S) and UPSI(2S) cross section.

No description provided.