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Comparison of Three Jet and Two Jet Cross-Sections in p anti-p Collisions at the CERN SPS p anti-p Collider

The UA1 collaboration Arnison, G. ; Allkofer, O.C. ; Astbury, A. ; et al.

Phys.Lett.B 158 (1985) 494, 1985.

Inspire Record 214736 DOI 10.17182/hepdata.30390

Results are presented on two-jet and three-jet cross sections, measured in the UA1 experiment at the CERN Super Proton Synchrotron (SPS) pp̄ Collider, at the highest available subprocess cms energies ( s ̂ >150 GeV ). Precise measurements of the two-jet angular distribution are consistent with previous results but show significant scale-breaking effects. The three-jet Dalitz plot and the three-jet angular distributions show evidence for final- and initial-state bremsstrahlung processes, in agreement with the leading-order QCD predictions. A comparison of the yield of wide-angle three-jet events with the yield of two-jet events at smaller scattering angles gives for the strong interaction coupling constant: α s ( K 3J K 2J )=0.16±0.02±0.03 at Q 2 ≈4000 GeV 2 , where the factor K 3J K 2J may plausibly be assumed to be close to unity.

2 data tables

Table 1

No description provided.

Table 2

No description provided.

Inelastic Interaction of Anti-protons With $^{4}$He Nuclei Between 200-{MeV}/$c$ and 600-{MeV}/$c$

Balestra, F. ; Bussa, M.P. ; Busso, L. ; et al.

Phys.Lett.B 165 (1985) 265-269, 1985.

Inspire Record 214678 DOI 10.17182/hepdata.30306

The antiproton-helium reaction cross section has been measured at 19.6 and 48.7 MeV with a streamer chamber in a magnetic field. Charged prongs and negative pion multiplicities and cross sections for the production of 3 He are given. A comparison with p 2 H is performed. he previously obtained 179.6 MeV results are also taken into account.

4 data tables

Table 1

CROSS SECTIONS FOR THE INELASTIC EVENTS IN THE PBAR HE INTERACTIONS.

Table 2

No description provided.

Table 3

No description provided.

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A Measurement of the Total Cross-section and a Study of Inclusive Muon Production for the Process $e^+ e^- \to$ Hadrons in the Energy Range Between 39.79-{GeV} and 46.78-{GeV}

The JADE collaboration Bartel, W. ; Becker, L. ; Cords, D. ; et al.

Phys.Lett.B 160 (1985) 337-342, 1985.

Inspire Record 216799 DOI 10.17182/hepdata.30375

The total cross section and the inclusive muon cross section for the process e + e − → hadrons have been measured in the center of mass energy range between 39.79 and 46.78 GeV. The ratio R shows no significant structure. It has an average value of 4.13±0.08±0.14. An upper limit is set on the production of narrow resonances. Limits are obtained for pair-produced heavy quarks. The data are compared with the standard electroweak interaction model including QCD corrections taking into account the five known types of quarks. Upper limits are given for a possible structure of quarks and for effects of color octet leptons.

1 data table

Table 1

Figure 1 also shows energy scan of 'R'.

High Transverse Energy and High Transverse Momentum Events in $p \bar{p}$ and $p p$ Interactions at the {CERN} Intersecting Storage Rings

The CMOR collaboration Angelis, A.L.S. ; Basini, G. ; Besch, H.J. ; et al.

Nucl.Phys.B 263 (1986) 228-244, 1986.

Inspire Record 216800 DOI 10.17182/hepdata.33698

A comparison between p p and pp interactions at √ s = 52.7 GeV is presented for a total neutral transverse energy ( E T o ) trigger and for a high transverse momentum ( p T ) neutral cluster trigger. The rate of production of events in the range 6< E T o <20 GeV is observed to be 10% higher in p p collisions than in pp collisions. A study of the structure of the events shows this excess to be due to more isotropic events being produced in p p collisions. The ratio of the production cross section for single neutral clusters in p p and pp interactions in the range 1.25< p T <10 GeV/ c does not significantly differ from unity.

1 data table

Table 1

No description provided.

Evidence for a $\omega \rho^\pm \pi^\mp$ State in Diffractive Photoproduction

The Omega Photon collaboration Atkinson, M. ; Axon, T.J. ; Barberis, D. ; et al.

Z.Phys.C 29 (1985) 333, 1985.

Inspire Record 214344 DOI 10.17182/hepdata.16016

The photoproduction of the final state ω π+π−π0 has been studied as part of a survey of photoproduction in the energy range 20–70 GeV in the Omega spectrometer at CERN. The π+π−π0 system produced with the ω meson has a strongρ±π± component which is predominantlyI=1 andJπ=1+. For theωρ±π∓ state a spin-parity analysis favoursJπ=1−, and the mass spectrum peaks at 2.28±0.05 GeV. The fitted width is Γ=0.44±0.11 GeV. The photoproduction cross-section of theωρ±π∓ state, averaged over the energy range 25–60 GeV, is 150±50 nb.

1 data table

Table 1

Figure gives data in 7 momenta bins. Averaged result is given here.

Charm Hadron Properties in 360-GeV/c $\pi^-$ p-Interactions

The LEBC-EHS collaboration Aguilar-Benitez, M. ; Allison, W.W.M. ; Bailly, J.L. ; et al.

Z.Phys.C 31 (1986) 491-511, 1986.

Inspire Record 214935 DOI 10.17182/hepdata.15883

A study of the properties of charm particles produced in 360 GeV/c π-p interactions is reported. The experiment was performed using the high resolution hydrogen bubble chamber LEBC in association with the European Hybrid Spectrometer at the CERN SPS. Details of the exposure and operation of the spectrometer are given and the methods used to extract the charm data are presented. The essential physics results on the decay properties (lifetime, branching ratios) as well as on the hadroproduction properties (cross sections forD,$\bar D$,F, Λc,D, correlations between charm particles) are given.

2 data tables

Table 1

No description provided.

Table 2

No description provided.

Inclusive Production of Multistrange Hyperons From 11-{GeV}/$c K^- p$ Interactions

Aston, D. ; Carnegie, R.K. ; Dunwoodie, W.M. ; et al.

Phys.Rev.D 32 (1985) 2270, 1985.

Inspire Record 214256 DOI 10.17182/hepdata.70875

Large samples of inclusively produced Ξ−, Ω−, and Ξ0(1530) events are presented from a 1427 events/μb exposure of the large-aperture superconducting-solenoid spectrometer to an 11-GeV/c K− beam. Production characteristics of these states are compared with other data and shown to be consistent with hyperon exchange. Polarization of Ξ− shows an increase in magnitude with both Feynman x and transverse momentum. The Ξ− decay parameters are measured to be αΞ=-0.40±0.03 and ΦΞ=(5±10)° . Results of searches for higher-mass hyperons are presented. The Ξ−(1820)→Ξ0(1530)π− decay is observed, while we fail to confirm the existence of the Σ+(3170).

3 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

rivet Analysis
A Study of Energy-energy Correlations in $e^+ e^-$ Annihilations at $\sqrt{s}=34$.6-{GeV}

The PLUTO collaboration Berger, Christoph ; Genzel, H. ; Lackas, W. ; et al.

Z.Phys.C 28 (1985) 365, 1985.

Inspire Record 215869 DOI 10.17182/hepdata.16029

We present high statistics measurements of the energy-energy correlation (EEC) and its related asymmetry (AEEC) ine+e− annihilation at a c.m. energy of 34.6 GeV. We find that the energy dependence as well as the large angle behaviour of the latter are well described by perturbative QCD calculations toOα(s2). Non-perturbative effects are estimated with the help of fragmentation models in which different jet topologies are separated using (ɛ, δ) cuts, and found to be small. The extracted values of$\Lambda _{\overline {MS} }$ lie between 100 and 300 MeV.

2 data tables

Table 1

Corrected energy-energy correlation data.

Table 2

CORRECTED FORWARD-BACKWARD ASYMMETRY.