HEPData Search

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

Table 1

No description provided.

Table 2

No description provided.

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

Table 1

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.

Table 2

OBSERVATION OF J/PSI RESONANCE.

Table 3

OBSERVATION OF PSI(3700)0 RESONANCE.

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Results from pluto at petra

The PLUTO collaboration Berger, Christoph ; Genzel, H. ; Grigull, R. ; et al.

1 (1979) 343-349, 1979.

Inspire Record 148976 DOI 10.17182/hepdata.45229

None

1 data table

Table 1

No description provided.

Elastic and total $\pi^{+}\pi^{-}$ cross-sections from a high statistics measurement of the reaction $\pi^{-}p \to \pi^{+}\pi^{-}n$ at 63 GeV/c

Weilhammer, P. ; Berglund, A. ; Chabaud, V. ; et al.

2 (1979) 628-635, 1979.

Inspire Record 148986 DOI 10.17182/hepdata.75420

A sample of about 230000 events of the reaction pi /sup -/p to pi /sup +/ pi /sup -/n, measured with a magnetic forward spectrometer set up in an unseparated pi /sup -/ beam with a momentum of 63 GeV/c at the SPS has been analysed in terms of one pion exchange. The elastic pi /sup +/ pi /sup -/ cross section has been determined using an extrapolation to the pion pole in the mass range up to m( pi /sup +/ pi /sup -/)=4 GeV. The total pi /sup +/ pi /sup -/ cross section is obtained via the optical theorem. (7 refs).

5 data tables

Table 1

INTEGRATED 2- S-WAVE INTENSITY FOR 1500 TO 1800 MEV, INCLUDING SIGNIFICANT BACKGROUND.

Table 2

No description provided.

Table 3

No description provided.

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rivet Analysis
Production Characteristics of the F Meson

The DASP collaboration Brandelik, R. ; Braunschweig, W. ; Martyn, H.U. ; et al.

Phys.Lett.B 80 (1979) 412-418, 1979.

Inspire Record 132410 DOI 10.17182/hepdata.27370

Inclusive cross sections of η production by e + e - annihilation for c.m. energies between 4.0 and 5.0 GeV are presented. The η production is shown to be correlated with the production of a weakly decaying particle, indicating that its main source is F production. At the 4.42 GeV resonance it is correlated with a low energy photon, suggesting F F ∗ or F ∗ F ∗ production. A mass determination of the F is made at 4.42 GeV using the F → ηπ decay channel.

1 data table

Table 1

NUMERICAL VALUES MEASURED FROM GRAPH IN PREPRINT. A CHARM MODEL (METHOD 2) GAVE CONSISTENT RESULTS FOR BACKGROUND SEPARATION.

$\Lambda$ and $\bar{\Lambda}$ Polarization in $K^\pm p$ Interactions at 32-{GeV}/$c$

The French-Soviet & CERN-Soviet collaborations Faccini-Turluer, M.L. ; Barloutaud, R. ; Cochet, C. ; et al.

Z.Phys.C 1 (1979) 19, 1979.

Inspire Record 132913 DOI 10.17182/hepdata.19291

Data on Λ and$\bar \Lambda $ polarization inK±p interactions at 32 GeV/c are presented. A comparison is made between the results of these two experiments as well as with the data at lower energies. The contribution of the different production mechanisms to the Λ($\bar \Lambda $) polarization are discussed.

2 data tables

Table 1

Data are presented on figures only. DATA NOT ENCODED.

Table 2

No description provided.

Measurement and Analysis of the Reaction $\pi^- p \to \rho^0 n$ on a Polarized Target

The CERN-Munich collaboration Becker, H. ; Blanar, G. ; Blum, W. ; et al.

Nucl.Phys.B 150 (1979) 301-325, 1979.

Inspire Record 132603 DOI 10.17182/hepdata.34819

The reaction π − p→ π + π − n has been measured in a high-statistics experiment on a transversely polarized proton target at 17.2 GeV, and unexpectedly large nucleon polarization effects have been observed. Combining the results of this experiment with a measurement on a hydrogen target allows a model-independent partial-wave analysis in terms of the “nucleon transversity” amplitudes. Unique or at most twofold ambiguous solutions are obtained. In particular we find a high lower limit ( ⪆30% ) of the spin non-flip unnatural exchange amplitudes at low | t |. These amplitudes, interpreted as being due to the exchange of an object with the quantum numbers of the A 1 , have been assumed to be absent in previous analyses. In checking the consequences of this finding on the old results, we test the validity of the rank-two assumotions for the density matrix. We find a small but significant deviation, which shows the need for a new phase-shift analysis including the A 1 exchange contribution.

2 data tables

Table 1

MASS DEPENDENCE OF NORMALIZED T-CHANNEL MOMENTS SCALED TO 100 PCT POLARIZED PROTONS.

Table 2

T DEPENDENCE OF NORMALIZED T-CHANNEL MOMENTS IN THE RHO REGION SCALED TO 100 PCT POLARIZED PROTONS.

rivet Analysis
Charged Pion, Kaon and Nucleon Production by e+ e- Annihilation for C.M. Energies Between 3.6-GeV and 5.2-GeV

The DASP collaboration Brandelik, R. ; Braunschweig, W. ; Martyn, H.U. ; et al.

Nucl.Phys.B 148 (1979) 189-227, 1979.

Inspire Record 132045 DOI 10.17182/hepdata.34826

Inclusive production of ifπ ± , K ± and p has been studied near charm threshold for c.m. energies between 3.6 and 5.2 GeV. Differential and scaling cross sections together with particle multiplicities have been determinated. By comparing data below and above charm threshold the charm contribution to if π ± and K ± production has been extracted. A comparison has been made between inclusice p production and inelastic electron-proton scattering. To study differences between three-gluon annihilation and two-quark production of the spectra from J/ decay and from non-resonant production at 3.6 GeV has been compared.

35 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Forward A2+ in Two-dimensions Production in $\pi^+ p \to K^+ \bar{K}(s$)0 $p$ at 12.7-{GeV}/$c$

Hyams, B. ; Jones, C. ; Weilhammer, P. ; et al.

Nucl.Phys.B 146 (1978) 303-326, 1978.

Inspire Record 132236 DOI 10.17182/hepdata.34849

Approximately 350 A 2 + events have been observed in the reaction π + p → K + K S 0 p ( K S 0 → π + π − ) at an incident π + laboratory momentum of 12.7 GeV/ c . The events are distributed over a range of four-momentum transfer squared 0.01 ⩽ − t ⩽ 0.60 (GeV/ c ) 2 and K + K S 0 mass 1.11 ⩽ m K + K S 0 ⩽ 1.51 GeV . A Breit-Wigner fit to the mass spectrum yields a mass for the A 2 + , m A 2 + = 1.324 ± 0.005 GeV, and a width Γ 0 = 0.110 ± 0.018 GeV. We find a cross section σ ( π + p → A 2 + p) = 1.71 ± 0.30 μb referring to the above-mentioned mass and t range and A 2 + → K + K S O with K S 0 → π + π − . The spin-space density matrix in the Gottfried-Jackson frame is practically saturated by ϱ 11 ⋍ ϱ 1−1 = 1 2 suggesting natural parity exchanges only. There is a forward dip in the angular distribution consistent with dominance of s -channel net helicity flip amplitudes and ϱ and f Regge exchanges suffice to describe adequately our differential cross sections.

5 data tables

Table 1

SUBTRACTED BACKGROUND IS PHASE SPACE. FITTED D(SIG)/DT SLOPE IS 9.5 +- 0.9 GEV**-2.

Table 2

SUBTRACTED BACKGROUND IS AN S-WAVE WITH SLOPE OF 8 GEV**-2. FITTED D(SIG)/DT SLOPE IS 6.9 +- 0.6 GEV**-2.

Table 3

FROM D(SIG)/DT. ERROR INCLUDES 15 PCT SCALE ERROR ADDED QUADRATICALLY.

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Inclusive and Semiinclusive Reactions With Neutral Kaons in $K^- p$ Interactions at 32-{GeV}/$c$

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

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

Results from pluto at petra

Elastic and total $\pi^{+}\pi^{-}$ cross-sections from a high statistics measurement of the reaction $\pi^{-}p \to \pi^{+}\pi^{-}n$ at 63 GeV/c

rivet Analysis
Production Characteristics of the F Meson

$\Lambda$ and $\bar{\Lambda}$ Polarization in $K^\pm p$ Interactions at 32-{GeV}/$c$

Measurement and Analysis of the Reaction $\pi^- p \to \rho^0 n$ on a Polarized Target

rivet Analysis
Charged Pion, Kaon and Nucleon Production by e+ e- Annihilation for C.M. Energies Between 3.6-GeV and 5.2-GeV

Forward A2+ in Two-dimensions Production in $\pi^+ p \to K^+ \bar{K}(s$)0 $p$ at 12.7-{GeV}/$c$