Date

Cross-Sections and Event Topologies in e+ e- Annihilation at 13-GeV and 17-GeV Observed with the PLUTO Detector

The PLUTO collaboration Berger, Christoph ; Genzel, H. ; Grigull, R. ; et al.
Phys.Lett.B 81 (1979) 410-415, 1979.
Inspire Record 140294 DOI 10.17182/hepdata.45239

First results from the magnetic detector PLUTO at the new e + e − storage ring PETRA are shown. The ratio R of the cross section for hadron production to that for μ-pair production has been measured to be R = 5.0 ± 0.5 at 13 GeV and 4.3 ±0.5 at 17 GeV. Both values have an additional systematic error of 20%. The events show a typical 2-jet structure. The mean transverse momentum approaches a constant value with increasing energy implying a shrinkage of the jet opening angle.

2 data tables

TAU HEAVY LEPTON PAIR CONTRIBUTIONS HAVE BEEN SUBTRACTED. R AT 13 AND 17 GEV, TOGETHER WITH SOME SELECTED LOWER ENERGY MEASUREMENTS FROM PLUTO AT DORIS.

Data from earlier preprint DESY-79-06. NUMERICAL VALUES MEASURED OFF GRAPH IN PREPRINT.


Measurement of the Relative Total Hadronic Cross-section R at {PETRA}

The Aachen-DESY-Annecy(LAPP)-MIT-NIKHEF-Beijing collaboration Barber, D. ; Becker, U. ; Boehm, A. ; et al.
Phys.Rev.Lett. 42 (1979) 1113, 1979.
Inspire Record 140059 DOI 10.17182/hepdata.3235

We report the first measurement of the ratio R=(σe+e−→hadrons)(σe+e−→μ+μ−) (with negligible τ-lepton contribution) at a center-of-mass energy s=13 GeV and s=17 GeV, from the just finished electron-positron colliding-beam facility PETRA. The detector, MARK-J, has an approximately 4π solid angle and measures γ, e, μ, and charged and neutral hadrons simultaneously. Our results yield R(s=17 GeV)=4.9±0.6 (statistical) ±0.7 (systematic error), and R(s=13 GeV)=4.6±0.5 (statistical) ±0.7 (systematic error). The ratio R(s=17 GeV)R(s=13 GeV) is 1.08±0.18.

2 data tables

No description provided.

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OBSERVATION IN THE K+ K- SYSTEM OF A NEW STRUCTURE AT 2.2-GEV

The BARI-BONN-CERN-DARESBURY-GLASGOW-LIVERPOOL-MILAN-VIENNA collaboration Evangelista, C. ; Ghidini, B. ; Palano, A. ; et al.
Nucl.Phys.B 154 (1979) 381-393, 1979.
Inspire Record 146574 DOI 10.17182/hepdata.34680

A sample of 56 909 events of the reaction π − p→K + K − n at 10 GeV/ c has been measured in the Omega Spectrometer at CERN. In the K + K − system, besides production of mesons in the S ∗ /φ, f 0 / A 2 , g /ω ∗ and h regions we observe a new structure at 2.20 GeV with a width of the order of 200 MeV.

1 data table

BREIT-WIGNER RESONANCES PLUS SMOOTH BACKGROUND FITTED TO K+ K- MASS SPECTRUM. RESTRICTIVE T-CUTS TO ENHANCE THE X(2200) GIVE CONSISTENT RESULTS.


NEUTRON DISSOCIATION INTO P PI- AT 19-GEV/C

Bakken, V. ; Jacobsen, T. ; Gennow, H. ; et al.
Nuovo Cim.A 49 (1979) 465-483, 1979.
Inspire Record 145707 DOI 10.17182/hepdata.37532

The reaction pn→ppπ at 19 GeV/c is studied. It is dominated by the process where the neutron dissociates into the pπ- system and exhibits the characteristic features of diffraction dissociation. The pπ- mass distribution shows a strong peak at 1.3 GeV but is otherwise rather structureless. By comparison with other experiments we find that this peak is neither seen at higher nor at lower energies. The reason why it is not seen in experiments at higher energies seems to be that they suffer from strong experimental limitations. The 1.3 GeV peak is connected with small momentum transfers and an analysis of the moments of the decay angular distributions shows that this peak is a low-spin phenomenon. For larger momentum transfers the lowest moments show an onset already at threshold. By comparison with a pion exchange Deck model we find a substantial baryon exchange contribution for small momentum transfers. This contribution seems to become more pronounced at higher energies.

1 data table

CORRECTED FOR UNOBSERVED DECAY MODES.


EXPERIMENTAL STUDY OF THE REACTION neutrino N ---> MU- P

The GARGAMELLE NEUTRINO PROPANE collaboration Pohl, M. ; Dewit, M. ; Haidt, D. ; et al.
Lett.Nuovo Cim. 26 (1979) 332-336, 1979.
Inspire Record 144819 DOI 10.17182/hepdata.37737

None

1 data table

Measured Quasi-Elastic total cross section.


RESULTS FROM DASP ON E+ E- ANNIHILATION BETWEEN 3.1-GEV AND 5.2-GEV

The DASP collaboration Brandelik, R. ; Braunschweig, W. ; Martyn, H.U. ; et al.
Z.Phys.C 1 (1979) 233-256, 1979.
Inspire Record 145403 DOI 10.17182/hepdata.16476

This paper summarizes the measurements one+e− annihilation performed by the DASP Collaboration in the energy range between 3.1 and 5.2 GeV. The following topics are covered: total cross section, production and two body decays of the narrow resonances, radiative decays of theJ/ψ and ψ′ resonances and evidence for theX(2.82), ψ′ cascade decays, inclusive η production and evidence for theF meson, semileptonic decays of charmed mesons and properties of the heavy lepton.

5 data tables

THESE DATA ON R WERE PUBLISHED IN R. BRANDELIK ET AL., PL 76B, 361 (1978), THE RECORD OF WHICH HAS TABULATED CROSS SECTIONS WITH AND WITHOUT THE TAU HEAVY LEPTON CONTRIBUTION.

OBSERVATION OF J/PSI RESONANCE.

OBSERVATION OF PSI(3700)0 RESONANCE.

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INCLUSIVE DELTA++ (1232) AND SIGMA+- (1385) PRODUCTION IN K- P INTERACTIONS AT 32-GEV/C. FRANCE-SOVIET UNION AND CERN-SOVIET UNION COLLABORATIONS

Walter, M. ; Becker, L. ; Klabuhn, J. ; et al.
Z.Phys.C 3 (1979) 89-95, 1979.
Inspire Record 148164 DOI 10.17182/hepdata.15987

We have studied inclusiveΔ++ (1232),∑+ (1385), and∑− (1385) baryon resonance production inK−p interactions at 32 GeV/c. The inclusive and topological cross sections are estimated and compared with published results at lower energies. No energy variation of the cross section is observed forΔ++ (1232) and only a slight decrease is seen in case of∑± (1385). The production properties are investigated through longitudinal and transverse momentum distributions. TheΔ++ (1232) is dominantly produced in the target fragmentation region. The∑+ (1385) is produced both in the target fragmentation region and in the central region, while the∑− (1385) is predominantly produced in the central region. About 20% of the final state protons are produced via aΔ++ (1232) decay and about 25% of the Λ produced come from the decay of∑+ (1385) and∑− (1385).

3 data tables

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NEUTRAL PARTICLE PRODUCTION IN PI P INTERACTIONS AT 147-GeV/c AND COMPARISON TO CHARGED PARTICLE PRODUCTION

Brick, D. ; Fong, D. ; Heller, M. ; et al.
Phys.Rev.D 20 (1979) 2123-2134, 1979.
Inspire Record 147455 DOI 10.17182/hepdata.4386

The production of KS, Λ, Λ¯, and γ in π−p collisions at 147 GeV/c is analyzed. Cross sections, rapidity, Feynman-x, and pT2 distributions are presented and compared to charged-particle production. The energy dependence of multiplicities in π−p and pp collisions is shown. A new scaling form for the correlation of neutral- and charged-particle multiplicities is presented for compilations of πp and pp data.

2 data tables

Axis error includes +- 0.0/0.0 contribution (?////ERRORS QUOTED ARE MAINLY STATISTICAL BUT INCLUDE CONTRIBUTIONS FROM ESTIMATES OF CONTAMINATION AND OF THE RELIABILITY OF WEIGHTING SCHEMES10 PCT OF ALAMBDA EVENTS COULD BE GAMMA CONTAMINATION, 0.5 PCT OF KS EVENTS COULD HAVE BEEN MISCLASSIFIED AS GAMMA'S).

Axis error includes +- 0.0/0.0 contribution (?////ERRORS QUOTED ARE MAINLY STATISTICAL BUT INCLUDE CONTRIBUTIONS FROM ESTIMATES OF CONTAMINATION AND OF THE RELIABILITY OF WEIGHTING SCHEMES10 PCT OF ALAMBDA EVENTS COULD BE GAMMA CONTAMINATION, 0.5 PCT OF KS EVENTS COULD HAVE BEEN MISCLASSIFIED AS GAMMA'S).


HYPERON PRODUCTION IN P P INTERACTIONS AT S**(1/2) = 53-GEV AND 62-GEV

Erhan, S. ; Lockman, William S. ; Meyer, T. ; et al.
Phys.Lett.B 85 (1979) 447-451, 1979.
Inspire Record 146771 DOI 10.17182/hepdata.5503

Inclusive measurements of Λ 0 , Λ 0 , Ξ − , Σ(1385) ± ) production in the forward direction at the CERN intersecting storage rings are presented. A signal for simulataneous Λ 0 Λ 0 production is also observed with total x > 0.6, 2.3 < M Λ Λ < 2.5 GeV and with a cross section of (1.7 ± 0.2) μb.

6 data tables

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INCLUSIVE PRODUCTION OF K*+- (890) AND SIGMA+- (1385) RESONANCES IN ANTI-P P INTERACTIONS AT 14.75-GEV/C

Canter, J. ; Chang, C.C ; Dao, F.T. ; et al.
Phys.Rev.D 20 (1979) 1029-1036, 1979.
Inspire Record 144992 DOI 10.17182/hepdata.24210

The inclusive and semi-inclusive cross sections for K*±(890) and Σ±(1385) resonances are determined in p¯p interactions at 14.75 GeV/c. They account for a large fraction of the KS0 and Λ0 produced. The K*-resonance production also affects the low-pT2 distribution of inclusive KS0. The x distributions of the resonance production are studied in terms of a simple quark-recombination model.

4 data tables

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