HEPData Search

Showing 10 of 23 results

Xi and Antixi production in 158-GeV/nucleon Pb + Pb collisions.

The NA49 collaboration Appelshäuser, H. ; Bächler, J. ; Bailey, S.J. ; et al.

Phys.Lett.B 444 (1998) 523-530, 1998.

Inspire Record 477539 DOI 10.17182/hepdata.31330

We report measurements of Xi and Xi-bar hyperon absolute yields as a function of rapidity in 158 GeV/c Pb+Pb collisions. At midrapidity, dN/dy = 2.29 +/- 0.12 for Xi, and 0.52 +/- 0.05 for Xi-bar, leading to the ratio of Xi-bar/Xi = 0.23 +/- 0.03. Inverse slope parameters fitted to the measured transverse mass spectra are of the order of 300 MeV near mid-rapidity. The estimated total yield of Xi particles in Pb+Pb central interactions amounts to 7.4 +/- 1.0 per collision. Comparison to Xi production in properly scaled p+p reactions at the same energy reveals a dramatic enhancement (about one order of magnitude) of Xi production in Pb+Pb central collisions over elementary hadron interactions.

2 data tables

Table 1

Data are given at the midrapidity value.

Table 2

Requested data from authors.

rivet Analysis
QCD studies with e+ e- annihilation data at 161-GeV.

The OPAL collaboration Ackerstaff, K. ; Alexander, G. ; Allison, John ; et al.

Z.Phys.C 75 (1997) 193-207, 1997.

Inspire Record 440721 DOI 10.17182/hepdata.47487

We have studied hadronic events produced at LEP at a centre-of-mass energy of 161 GeV. We present distributions of event shape variables, jet rates, charged particle momentum spectra and multiplicities. We determine the strong coupling strength to be αs(161 GeV) = 0.101±0.005(stat.)±0.007(syst.), the mean charged particle multiplicity to be 〈nch〉(161 GeV) = 24.46 ± 0.45(stat.) ± 0.44(syst.) and the position of the peak in the ξp = ln(1/xp) distribution to be ξ0(161 GeV) = 4.00 ±0.03(stat.)±0.04(syst.). These results are compared to data taken at lower centre-of-mass energies and to analytic QCD or Monte Carlo predictions. Our measured value of αs(161 GeV) is consistent with other measurements of αs. Within the current statistical and systematic uncertainties, the PYTHIA, HERWIG and ARIADNE QCD Monte Carlo models and analytic calculations are in overall agreement with our measurements. The COJETS QCD Monte Carlo is in general agreement with the data for momentum weighted distributions like Thrust, but predicts a significantly larger charged particle multiplicity than is observed experimentally.

26 data tables

Table 1

Determination of alpha_s.

Table 2

Multiplicity and higher moments.

Table 3

Thrust distribution.

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QCD studies with e+ e- annihilation data at 130-GeV and 136-GeV.

The OPAL collaboration Alexander, G. ; Allison, John ; Altekamp, N. ; et al.

Z.Phys.C 72 (1996) 191-206, 1996.

Inspire Record 418007 DOI 10.17182/hepdata.47564

We have studied hadronic events produced at LEP at centre-of-mass energies of 130 and 136 GeV. Distributions of event shape observables, jet rates, momentum spectra and multiplicities are presented and compared to the predictions of several Monte Carlo models and analytic QCD calculations. From fits of event shape and jet rate distributions to${\mathcal{O}}(\alpha _s^2 ) + NLLA$ QCD calculations, we determineαs(133 GeV)=0.110±0.005(stat.)±0.009(syst.). We measure the mean charged particle multiplicity 〈nch〉=23.40±0.45(stat.) ±0.47(syst.) and the position ζ0 of the peak in the ζp = ln(1/xp) distribution ζ0=3.94±0.05(stat.)±0.11(syst.). These results are compared to lower energy data and to analytic QCD or Monte Carlo predictions for their energy evolution.

23 data tables

Table 1

Determination of alpha_s.

Table 2

Multiplicity and high moments.

Table 3

Tmajor distribution.

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rivet Analysis
Measurement of inclusive Lambda production in electron - positron interactions at the upsilon energies

Blinov, A.E. ; Blinov, V.E. ; Bondar, A.E. ; et al.

Z.Phys.C 62 (1994) 367-370, 1994.

Inspire Record 362599 DOI 10.17182/hepdata.14205

Using the MD-1 detector at the VEPP-4e+e− strorage ring we have measured the inclusive Λ and370-1 production rates in direct Γ(1S) decays

4 data tables

Table 1

Lambda x spectrum in direct upsilon(1S) decay.

Table 2

Lambda multiplicity in direct upsilon(1S) decays.

Table 3

Lambda multiplicity in surrounding continuum.

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Relativistic alpha particles from inelastic collisions of nuclei of Mg-24 in photoemulsion at 4.5-GeV/c/nucleon)

Bondarenko, A.I. ; Rusakova, V.V. ; Salomov, Dzh.A. ; et al.

Sov.Phys.J. 34 (1991) 400-404, 1991.

Inspire Record 327154 DOI 10.17182/hepdata.39924

None

1 data table

Table 1

No description provided.

Inclusive production of vector mesons in pi+ p interactions at 250-GeV/c

The EHS/NA22 collaboration Agababyan, N.M. ; Ajinenko, I.V. ; Belokopytov, Yu. A. ; et al.

Z.Phys.C 46 (1990) 387-395, 1990.

Inspire Record 301243 DOI 10.17182/hepdata.15240

We report on a study of ρ0, ρ+, ω,$\bar K^{*0} (892)$ andK*0 (892) inclusive production in π+p interactions at 250 GeV/c, for ρ+,$\bar K^{*0} (892)$ for the first time in a π+p experiment. The data are compared withK+p data in the same experiment, with results of other experiments and with quark-parton models. Interesting differences are found between ρ+,0 and ω production.

10 data tables

Table 1

Inclusive cross sections and average multiplicity per inelastic collision.

Table 2

No description provided.

Table 3

No description provided.