HEPData Search

Production rates of multijet hadronic final states are studied ine+e− annihilation at 29 GeV center of mass energy. QCD shower model calculations with exact first order matrix element weighting at the first gluon vertex are capable of reproducing the observed multijet event rates over a large range of jet pair masses. The method used to reconstruct jets is well suited for directly comparing experimental jet rates with parton rates calculated in perturbative QCD. Evidence for the energy dependene of αs is obtained by comparing the observed production rates of 3-jet events with results of similar studies performed at higher center of mass energies.

2 data tables

Table 1

Observed production rates relative to the total hadronic cross section.

Table 2

Production rates corrected for fragmentation, initial state radiation and detector effects.

Dijet Angular Distributions from anti-p p Collisions at s**(1/2) = 1.8-TeV

The CDF collaboration Abe, F. ; Amidei, D. ; Apollinari, G. ; et al.

Phys.Rev.Lett. 62 (1989) 3020-3023, 1989.

Inspire Record 278394 DOI 10.17182/hepdata.20046

We have measured dijet angular distributions at √s =1.8 TeV with the Collider Detector at Fermilab and the Tevatron p¯p Collider and find agreement with leading-order QCD. By comparing the distribution for the highest dijet invariant masses with the prediction of a model of quark compositeness, we set a lower limit on the associated scale parameter Λc at 330 GeV (95% C.L.).

1 data table

Table 1

Numerical values read from figure in preprint.

CENTRAL INTERACTIONS OF Ne-22 NUCLEI WITH HEAVY PHOTOEMULSION NUCLEI AT P(0) = 4.1/A-GeV/c

The Alma Ata-Bucharest-Gatchina:Dubna-Dushanbe-Yerevan-Zernograd- Kosice-Cracow-Leningrad-Moscow-Tashkent-Tbilisi-Ulan Bator collaboration Andreeva, N.P. ; Anzon, Z.V. ; Ameeva, B.U. ; et al.

JINR-P1-89-213, 1989.

Inspire Record 281512 DOI 10.17182/hepdata.38837

None

5 data tables

Table 1

NUCLEUS IS NUCLEAR PHOTOEMULSION. EVENT WITH A TOTAL CHARGE OF ALL SPECTATOR FRAGMENTS OF A PROJECTILE = 0.

Table 2

NUCLEUS IS NUCLEAR PHOTOEMULSION. EVENT WITH A TOTAL CHARGET OF ALL SPECTATOR FRAGMENTS OF A PROJECTILE = 1.

Table 3

NUCLEUS IS NUCLEAR PHOTOEMULSION.

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Hyperon Production at 200-{GeV} and 900-{GeV} Center-of-mass Energy

The UA5 collaboration Ansorge, R.E. ; Asman, B. ; Burow, L. ; et al.

Nucl.Phys.B 328 (1989) 36-58, 1989.

Inspire Record 277298 DOI 10.17182/hepdata.33174

The production of Λ 's and Ξ − 's in proton-antiproton collisions at 200 and 900 GeV c.m. energy has been studied using decays observed in the UA5 streamer chambers. The results are compared to previously published 546 GeV data, to results from other experiments, and to four theoretical models. The Λ yield per inelastic event is estimated to be 0.42±0.11 at 200 GeV and 0.66±0.14 at 900 GeV. We find a mean number of Ξ − 's per inelastic collision of 0.03 −0.02 +0.04 at 200 GeV and 0.06 −0.03 +0.05 at 900 GeV. The average transverse momentum of Λ's in the rapidity region | y |⩽2 is found to be 0.80 −0.14 +0.20 GeV/ c at 200 GeV and 0.74±0.09 GeV/ c at 900 GeV. The average transverse momentum of Ξ − 's in the rapidity region | y |⩽3 is estimated to be 0.8 −0.2 +0.4 GeV/ c at 200 GeV and 0.7 −0.1 +0.2 GeV/ c at 900 GeV which is lower than the unexpectedly high value of 1.1±0.2 GeV/ c measured at 546 GeV. The ratio of Ξ − production to Λ production in the region | y |⩽2, p t >1 GeV/ c is 0.07 −0.04 +0.08 at 900 GeV. This value is consistent with the ratio found in e + e − collisions and lower energy pp collisions but lower than the value obtained at 546 GeV. The average particle composition of events at 200 and 900 GeV, estimated using UA5 data, is presented.

9 data tables

Table 1

Corrected lambda transverse momentum distributions. Numerical values supplied by F. Lotse. Data at 546 GeV are taken from an earlier publication - Phys. Rep. 154 (87) 247.

Table 2

Data at 546 GeV are taken from an earlier publication - Phys. Rep. 154 (87) 247.

Table 3

Corrected lambda transverse momentum distributions. Numerical values supplied by F. Lotse. Data at 546 GeV are taken from an earlier publication - Phys. Rep. 154 (87) 247.

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$\Lambda$(c)+ Production and Semileptonic Decay in 29-{GeV} $e^+ e^-$ Annihilation

Klein, S. ; Himel, T. ; Abrams, G.S. ; et al.

Phys.Rev.Lett. 62 (1989) 2444, 1989.

Inspire Record 277034 DOI 10.17182/hepdata.20042

We present results on Λc+ production in 29-GeV e+e− annihilation. The Λc+ are observed via their semileptonic decays to Λe+X and Λμ+X. With radiative corrections, we find σ(e+e−→Λc+X)〉BΛc+→eΛX)= 1.5±0.6±0.5 pb or 0.0038±0.0015±0.0012 Λc+→Λe+X decay per hadronic event, and σ(e+e−Λc+X)B(Λc+→μΛX)= 1.4±1.4±0.4 pb or 0.0035±0.0035±0.0011 Λc+→Λμ+X decay per hadronic event. These results can be used to place constraints on the predictions of various production models.

2 data tables

Table 1

Cross sections * branching ratio for LAMBDA/C+ production in LAMBDA E+ decay channel.

Table 2

Cross sections * branching ratio for LAMBDA/C+ production in LAMBDA MU+ decay channel.

$\tau$ Production and Decay With the Cello Detector at {PETRA}

The CELLO collaboration Behrend, H.J. ; Criegee, L. ; Dainton, J.B. ; et al.

Phys.Lett.B 222 (1989) 163-172, 1989.

Inspire Record 276859 DOI 10.17182/hepdata.29824

The reaction e + e − → τ + τ − has been studied at centre of mass energies between 14.0 and 46.8 GeV with the CELLO detector at the PETRA e + e − collider. We present results for the cross section σ τ and the charge asymmetry A τ . The results are in good agreement with the standard model. We have also measured the topological decay rates BR 1 , BR 3 and BR 5 for the inclusive decay of the τ lepton into one, three and five charge particles. The results confirm and improve earlier CELLO measurements at other energies. We find for the combined values at all energies BR 1 = (84.9 ± 0.4 ± 0.3)%, BR 3 = (15.0 ± 0.4 ± 0.3)% and BR 5 = (0.16 ± 0.13 ± 0.04)%.

3 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

Corrected for radiative effects and background contributions.

rivet Analysis
Inclusive Production of Charged Pions, Charged and Neutral Kaons and Anti-protons in $e^+ e^-$ Annihilation at 10-{GeV} and in Direct $\Upsilon$ Decays

The ARGUS collaboration Albrecht, H. ; Bockmann, P. ; Glaser, R. ; et al.

Z.Phys.C 44 (1989) 547, 1989.

Inspire Record 276860 DOI 10.17182/hepdata.15362

Using the ARGUS detector at thee+e− storage ring DORIS II, we have investigated inclusive production of π±,K±,Ks0 and$\bar p$ in multihadron events at 9.98 GeV and in direct decays of the ϒ(1S) meson, i.e. from quark and gluon fragmentation. The most pronounced difference is the rate of baryon production. The Lund Monte Carlo program gives a reasonable qualitative description, although it cannot reproduce our data in detail.

12 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Atomic Weight Dependence of the Production of Hadron Pairs from 800-GeV/c Protons on Nuclear Targets

Turner, Kathleen R. ; Boca, G. ; Georgiopoulos, C. ; et al.

Phys.Rev.Lett. 66 (1991) 864-867, 1991.

Inspire Record 278395 DOI 10.17182/hepdata.19892

Fermilab experiment 711 has investigated proton-nucleus collisions in which two high-transverse-momentum hadrons are produced forming high-mass ++, +-, and -- charged states, using an 800-GeV/c proton beam on targets of beryllium, aluminum, iron, and tungsten. Our data cover the range in dihadron mass from 6 to 15 GeV/c2. We show here that the dependence of the cross section on atomic weight A can be parametrized as Aα where α=1.043±0.011(stat)±0.025 (syst), and is independent of the charge state of the dihadron system.

3 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

K0(S) PRODUCTION IN ANTI-P P INTERACTIONS AT S**(1/2) = 630-GeV AND 1800-GEV

The CDF collaboration Abe, F. ; Amidei, D. ; Apollinari, G. ; et al.

Phys.Rev.D 40 (1989) 3791-3794, 1989.

Inspire Record 287811 DOI 10.17182/hepdata.22999

Measurements of inclusive transverse-momentum spectra for KS0 mesons produced in proton-antiproton collisions at s of 630 and 1800 GeV are presented and compared with data taken at lower energies. The ratio, as a function of pT, of the cross section for KS0 to that for charged hadrons is very similar to what is observed at lower energies. At 1800 GeV, we calculate the strangeness-suppression factor λ=0.40±0.05.

4 data tables

Table 1

Estimated effective cross sections for events which pass the trigger and selection criteria. The uncertainties in these represent the principal source of error in the overall normalisation of the results.

Table 2

Statistical errors only.

Table 3

Statistical errors only.

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CM Energies (GeV)

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Study of rho0 and f2 meson production in pi- p interactions at 360-GeV/c

Studies of Jet Production Rates in $e^+ e^-$ Annihilation at $e$({CM}) = 29-{GeV}

Dijet Angular Distributions from anti-p p Collisions at s**(1/2) = 1.8-TeV

CENTRAL INTERACTIONS OF Ne-22 NUCLEI WITH HEAVY PHOTOEMULSION NUCLEI AT P(0) = 4.1/A-GeV/c

Hyperon Production at 200-{GeV} and 900-{GeV} Center-of-mass Energy

$\Lambda$(c)+ Production and Semileptonic Decay in 29-{GeV} $e^+ e^-$ Annihilation

$\tau$ Production and Decay With the Cello Detector at {PETRA}

rivet Analysis
Inclusive Production of Charged Pions, Charged and Neutral Kaons and Anti-protons in $e^+ e^-$ Annihilation at 10-{GeV} and in Direct $\Upsilon$ Decays

Atomic Weight Dependence of the Production of Hadron Pairs from 800-GeV/c Protons on Nuclear Targets

K0(S) PRODUCTION IN ANTI-P P INTERACTIONS AT S**(1/2) = 630-GeV AND 1800-GEV