Bertolucci, S.
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rivet Analysis
Angular Correlations in gamma Gamma ---> rho0 rho0 Near Threshold

The TASSO collaboration Althoff, M. ; Braunschweig, W. ; Gather, K. ; et al.
Z.Phys.C 16 (1982) 13, 1982.
Inspire Record 180755 DOI 10.17182/hepdata.16415

We present an analysis ofρ0ρ0 production by two photons in theρ0ρ0 invariant mass range from 1.2 to 2.0 GeV. From a study of the angular correlations in the process γγ→ρ0ρ0→π−π+π− we exclude a dominant contribution fromJP=0− or 2− states. The data indicate sizeable contributions fromJP=0+ for four pion massesM4π<1.7 GeV and fromJP=2+ forM4π>1.7 GeV. The data are also well described by a model with isotropic production and uncorrelated isotropic decay of theρ0,s. The cross section stays high below the nominalρ0ρ0 threshold, i.e.M4π<1.5 GeV. The matrix element forρ0ρ0 production is found to decrease steeply with increasingM4π. Upper limits for the couplings of the ι(1440) and Θ(1640) to γγ andρ0ρ0 are given:Γ(ι→γγ)·B(ι→ρ0ρ0)<1.0 keV andΓ(Θ→γγ)

2 data tables
Table 1

ASSUMING ISOTROPIC RHO0 RHO0 PRODUCTION AND ISOTROPIC RHO DECAY.

Table 2

CROSS SECTIONS FOR DIFFERENT SPIN-PARITY CONTRIBUTIONS.


Experimental Study of the Photon Structure Function F(2) in the High $Q^2$ Region

The JADE collaboration Bartel, W. ; Cords, D. ; Dietrich, G. ; et al.
Phys.Lett.B 121 (1983) 203-208, 1983.
Inspire Record 180758 DOI 10.17182/hepdata.30781

We report on a measurement of the process e + e − →e + e − + hadrons, where one of the scattered electrons is detected at large angles, with an average Q 2 of 23 GeV. The results are analysed in terms of the photon structure function F 2 and are compared with QCD predictions.

3 data tables
Table 1

Data read off graph.

Table 2

Data read off graph.

Table 3

Data read off graph.


Differential Three Jet Cross-section in $e^+ e^-$ Annihilation and Comparison With Second Order Predictions of {QCD} and Abelian Vector Theory

The JADE collaboration Bartel, W. ; Cords, D. ; Dietrich, G. ; et al.
Phys.Lett.B 119 (1982) 239-244, 1982.
Inspire Record 180033 DOI 10.17182/hepdata.30830

Differential three-jet cross sections have been measured in e + e − -annihilation at an average CM energy of 33.8 GeV and were compared to first- and second-order predictions of QCD and of a QED-like abelian vector theory. QCD provides a good description of the observed distributions. The inclusion of second-order effects reduced the observed quark-gluon coupling strength by about 20% to α S = 0.16 ± 0.015 (stat.) ± 0.03 (syst.). The abelian vector theory is found to be incompatible with the data.

2 data tables
Table 1

FIRST ORDER QCD.

Table 2

SECOND ORDER QCD.


Direct Evidence for the Emergence of Jets in Events Triggered on Large Transverse Energy in $p p$ Collisions at $\sqrt{s}=63$-{GeV}

The Axial Field Spectrometer collaboration Akesson, T. ; Albrow, M.G. ; Almehed, S. ; et al.
Phys.Lett.B 118 (1982) 185-192, 1982.
Inspire Record 179517 DOI 10.17182/hepdata.30854

We present data obtained from a 1.7 sr hadron calorimeter, triggered on transverse energy, in pp collisions at s =63 GeV at the CERN-ISR. From the change in the distribution of energy in the calorimeter, we extract the cross section for two-constituent hard scattering for p T between 6 and 14 GeV at y = 0. The decrease of this jet cross section over this p T range is consistent with exp (− bp T ), with b = (1.02 ± 0.09) GeV −1 . The slope and normalization of the cross section agree well with a QCD motivated Monte Carlo model. The ratio between jet and single particle cross sections [ dσ JET / dp T )/( dσ π 0 / dp T )]| y = 0 changes from about 200 at 6 GeV to about 1500 at 14 GeV.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


Transverse Momentum Spectra for Charged Particles at the CERN Proton anti-Proton Collider

The UA1 collaboration Arnison, G. ; Astbury, A. ; Aubert, Bernard ; et al.
Phys.Lett.B 118 (1982) 167-172, 1982.
Inspire Record 179520 DOI 10.17182/hepdata.30855

We have measured transverse momentum spectra up to 10 GeV/ c for charged particles produced centrally in proton-antiproton collisions at 540 GeV in the centre of mass at the CERN collider. Our results are compared with data at ISR energies and with the predictions of a QCD model. The charged particle spectrum shows a clear dependence on charged track multiplicity.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


Multiplicity Distributions in $p \alpha$ and $\alpha \alpha$ Collisions in the {CERN} {ISR}

The Axial Field Spectrometer collaboration Akesson, T. ; Albrow, M.G. ; Almehed, S. ; et al.
Phys.Lett.B 119 (1982) 464, 1982.
Inspire Record 179518 DOI 10.17182/hepdata.6665

Measurements of charged particle multiplicity distributions in the central rapidity region in p-p and p-α, and α-α collisions are reported. They are better fitted to the “wounded nucleon” than to the “gluon string” model. The average transverse momenta, for all three reactions, are identical (and almost independent of multiplicity) up to very high multiplicities.

2 data tables
Table 1

THE FIRST PP DATA IS AT 44 GEV, THE SECOND AT 63 GEV.

Table 2

No description provided.


Small Angle Elastic Scattering at the {CERN} Proton Anti-proton Collider

The UA1 collaboration Arnison, G. ; Astbury, A. ; Aubert, Bernard ; et al.
Phys.Lett.B 121 (1983) 77-82, 1983.
Inspire Record 180683 DOI 10.17182/hepdata.66558

3roton-antiproton elastic scattering at cm energy 540 GeV has been studied in the t range 0.14 ⩽ − t ⩽ 0.26 GeV 2 . The data is well fitted by an exponential form exp( bt ) with b = 13.3 ± 1.5 GeV −2 .

2 data tables
Table 1

Elastic Differentiaol Cross Section (545 events). DATA REQUESTED 21 FEB 1983. Data read from plot in paper (29 JAN 2015).

Table 2

No description provided.


LIMITS ON BARYONIUM PRODUCTION IN anti-p p INTERACTIONS AT 8.3-GeV/c AND 13.0-GeV/c

Barnett, B. ; Blockus, D. ; Burka, M. ; et al.
Phys.Rev.D 27 (1983) 493, 1983.
Inspire Record 12635 DOI 10.17182/hepdata.23803

Results are presented from a search for the production of narrow p¯p states in antiproton interactions at 8.3 and 13.0 GeV/c. Cross-section upper limits have been established for four candidate baryonium states. The upper limits (95% probability level) range from 0.21 to 1.29 μb for inclusive forward production, and from 0.11 to 0.89 μb for backward production in the final state ωf0(p¯p).

2 data tables
Table 1

CROSS SECTIONS ARE UPPER LIMITS OF 95 PCT CL.

Table 2

CROSS SECTIONS ARE UPPER LIMITS OF 95 PCT CL.


An Experimental Study of Large Angle Elastic Scattering of Charged Mesons and Anti-protons on Protons at 20-{GeV}/$c$ and 30-{GeV}/$c$

The Annecy(LAPP)-CERN-Bohr Inst-Genoa-Oslo-London collaboration Baglin, C. ; Bock, R. ; Brobakken, K. ; et al.
Nucl.Phys.B 216 (1983) 1-39, 1983.
Inspire Record 180922 DOI 10.17182/hepdata.34020

A description is given of an experiment to study elastic scattering of π ± , K ± and p on protons at c.m. scattering angles from 45° to 100° at incident laboratory momenta 20 GeV/ c and 30 GeV/ c . The corresponding t range is from −6.2 (GeV/ c ) 2 to −28 (GeV/ c ) 2 . There are no previous observations for these reactions in this t range. High intensity and large geometrical acceptance were required in order to measure the low cross sections. The experiment used a double-arm spectrometer. MWPCs were used for reconstruction, and threshold and differential Čerenkov counters for identification. Scintillation counters, Čerenkov counters and a hadron calorimeter were used in the trigger. The trigger logic utilized specially designed matrices and a hard wired microprocessor. The π − p elastic scattering cross sections follow approximately the dimensional counting rule from 3.5 GeV/ c .and up to 30 GeV/ c . The cross sections decrease by seven orders of magnitude in this energy range. The data is compared to quark models. None of these models give a comprehensive description of the results. However, some modifications to these models improve their consistency with the data.

8 data tables
Table 1

EARLIER RESULTS GIVEN IN 'A'.

Table 2

No description provided.

Table 3

No description provided.

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Production of Charmonium in 250-GeV mu+ - Iron Interactions

The European Muon collaboration Aubert, J.J. ; Bassompierre, G. ; Becks, K.H. ; et al.
Nucl.Phys.B 213 (1983) 1-30, 1983.
Inspire Record 180791 DOI 10.17182/hepdata.34060

The production of J/ ϑ and ϑ′ has been measured in 250 GeV muon iron interactions. The measured total cross sections are σ ( μ N → μ J/ ϑ X)=0.74±0.14 nb and σ ( μ N → μϑ ′X)=0.16 ± 0.07 nb. An upper limit on the cross section times branching ratio for ϒ production of BR · σ ( μ N → μϒ X) < 5.2 × 10 −38 cm 2 (at 90% confidence level) is obtained. About half the J/ ϑ cross section is found to have Z ⩾ 0.95 (where Z = E (J/ ϑ / ν ). The first-order photon-gluon fusion model agrees well with the measured Q 2 and ν dependence of the J/ ϑ data and is used to extract the gluon momentum distribution. However, higher order QCD effects are needed to explain the Z distribution of the J/ ϑ and the observed broadening of the P t 2 distribution with decreasing Z . The decay angular distributions of the J/ ϑ are found to be flat in the s -channel frame, but there is evidence for polarisation in the t -channel frame.

5 data tables
Table 1

NUMBERS ARE CROSS-SECTIONS FOR PSI AND PSI(PRIME) BUT CROSS-SECTION*BR.RATIO FOR THE UPSILON.

Table 2

THE COHERENT PRODUCTION IS NOT SUBTRACTED.

Table 3

THE COHERENT PRODUCTION IS SUBTRACTED.

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