Date

A Test of Universality of Charged Leptons

Barber, D.P. ; Becker, U. ; Benda, H. ; et al.
Phys.Rev.Lett. 43 (1979) 1915, 1979.
Inspire Record 142012 DOI 10.17182/hepdata.20759

Measurements of the reactions e++e−→e++e−, μ++μ−, and τ++τ− at PETRA energies (s12=13,17,27.4,30 and 31.6 GeV) are reported. The results show that these reactions agree well with the predictions of quantum electrodynamics thus determining that all the known charged leptons are pointlike particles to a distance < × 10−16 cm.

2 data tables

No description provided.

No description provided.


Discovery of Three Jet Events and a Test of Quantum Chromodynamics at PETRA Energies

Barber, D.P. ; Becker, U. ; Benda, H. ; et al.
Phys.Rev.Lett. 43 (1979) 830, 1979.
Inspire Record 142085 DOI 10.17182/hepdata.20742

We report the analysis of the spatial energy distribution of data for e+e−→hadrons obtained with the MARK-J detector at PETRA. We define the quantity "oblateness" to describe the flat shape of the energy configuration and the three-jet structure which is unambiguously observed for the first time. Our data can be explained by quantum chromodynamic predictions for the production of quark-antiquark pairs accompanied by hard noncollinear gluons.

1 data table

AVERAGE OBLATENESS AS A FUNCTION OF SQRT(S) AND OF THRUST AND OBLATENESS DISTRIBUTION (1/N)*DN/DOBLATENESS AT 17 AND 27.4 TO 31.6 GEV. THESE DATA ARE RATHER DETECTOR DEPENDENT.


The hadronic final state in $e^{+}e^{-}$ annihilation at c.m. energies of 13, 17 and 27.4 GeV

The TASSO collaboration Cashmore, R.J. ; Brandelik, R. ; Braunschweig, W. ; et al.
1 (1979) 330-337, 1979.
Inspire Record 142275 DOI 10.17182/hepdata.45234

Results on the hadronic final state in e/sup +/e/sup -/ annihilation at 13, 17 and 27.4 GeV are presented. There is no compelling evidence for the existence of the t quark in these data, which are in general agreement with a simple quark parton model. Some tentative indications of QCD effects are observed in the p/sub T//sup 2/ distributions.

2 data tables

TAU HEAVY LEPTON CONTRIBUTION SUBTRACTED.

INCLUSIVE HADRON SPECTRUM. THESE DATA AT 13, 17 AND 27.4 GEV ON S*D(SIG)/DX ARE INCLUDED IN THE RECORD OF R. BRANDELIK ET AL., PL 89B, 418 (1980).


High Statistics Measurement of Polarization in $\pi^- p \to K^0 \Lambda$ at 3-{GeV}/$c$ and 5-{GeV}/$c$

Snyder, A. ; Ambats, I. ; Meyer, W.T. ; et al.
Phys.Rev.D 21 (1980) 599, 1980.
Inspire Record 8072 DOI 10.17182/hepdata.24173

We have measured the polarization of the Λ hyperon produced in the reaction π−p→K0Λ at 3 and 5 GeV/c, for four-momentum transfers t′ out to 1.6 GeV2, by observing the parity-violating decay Λ→pπ−. With an increase in statistical power by a factor of 3 to 4 over the best previous experiments in this energy range, we confirm earlier observations that the polarization is small and positive below t′=0.4 GeV2, becoming large and positive for larger values of t′. In particular, at 5 GeV/c for all t′ between 0.8 and 1.6 GeV2 the polarization is consistent with a value of - 1.

2 data tables

No description provided.

No description provided.


Cross-sections for Charged Current Neutrino and Anti-neutrino Interactions in the Energy Range 10-{GeV} to 50-{GeV}

Colley, D.C. ; Jones, G.T. ; O'Neale, S. ; et al.
Z.Phys.C 2 (1979) 187, 1979.
Inspire Record 141975 DOI 10.17182/hepdata.16366

Charged-current neutrino and antineutrino interaction cross sections have been measured in the energy range 10 to 50 GeV using BEBC filled with a neon-hydrogen mixture. At these energies, σ/E was measured to be (0.73±0.08) 10−38 cm2/GeV per nucleon for neutrinos and (0.32±0.06) 10−38 cm2/GeV per nucleon for antineutrinos.

2 data tables

Axis error includes +- 9/9 contribution (NEUTRAL CURRENT EVENTS AND NEUTRAL HADRON INDUCED REACTIONS, LOSSES OF EVENTS WITH ONLY ONE VISIBLE CHARGED PARTICLE).

Axis error includes +- 9/9 contribution (NEUTRAL CURRENT EVENTS AND NEUTRAL HADRON INDUCED REACTIONS, LOSSES OF EVENTS WITH ONLY ONE VISIBLE CHARGED PARTICLE).


Evidence for the b pi decay mode of the omega (1670)

The Birmingham-CERN-Glasgow-Michigan State-Paris collaboration Baubillier, M. ; Bloodworth, I.J. ; Bossen, G.J. ; et al.
Phys.Lett.B 89 (1979) 131-135, 1979.
Inspire Record 142040 DOI 10.17182/hepdata.27266

Backward production of ω (1670) is observed in the reactions K − p→ φ + φ − ω 0 Λ 0 and K − p→ φ + φ − φ 0 φ 0 for | U ' Λ |<1.0 GeV 2 . The cross section for the ω (1670) → φ + φ − ω 0 decay mode is 1.90±0.35 μ b for 8.25 GeV/ c incident K − . Evidence is presented for the importance of the sequential decay, ω (1670) → B φ → ωφφ with a branching ratio ω (1670) → B φ /all ω (1670) → ωφφ =1.0± 0.25 0.00 .

1 data table

No description provided.


Study of Electron - Positron Collisions at the Highest {PETRA} Energy

The Aachen-DESY-Annecy(LAPP)-MIT-NIKHEF-Beijing collaboration Barber, D.P. ; Becker, U. ; Benda, H. ; et al.
Phys.Lett.B 85 (1979) 463-466, 1979.
Inspire Record 141976 DOI 10.17182/hepdata.27332

We report on the results of the study of e + e − collisions at the highest PETRA energy of √ s = 31.57 GeV, using the 4π sr, electromagnetic and calorimetric detector Mark J. Based on 88 hadron events, and an integrated luminosity of 243 nb −1 we obtain R = σ (e + e − → hadrons)/ σ (e + e − → μ + μ − ) = 4.0 ± 0.5 (statistical) ± 6 (systematic). The R value, the measured thrust distribution and average spherocity show no evidence for the production of new quark flavors.

2 data tables

CORRECTIONS FOR TWO-PHOTON PROCESSES, TAU HEAVY LEPTON PRODUCTION AND INITIAL STATE RADIATIVE CORRECTIONS HAVE BEEN APPLIED.

THRUST DISTRIBUTION (1/N)*DN/DTHRUST AT 31.57 GEV. THESE DATA ARE RATHER DETECTOR DEPENDENT.


A Study of the $\Delta \pi \pi$ System in the Reaction $\pi^- p \to \pi^- p \pi^+ \pi^- \pi^0$ at 4.5-{GeV}/$c$

Sugahara, R. ; Suzuki, A. ; Fukawa, M. ; et al.
Nuovo Cim.A 52 (1979) 373, 1979.
Inspire Record 142331 DOI 10.17182/hepdata.37520

Two (Δ(1238)ππ) enhancements at 1.93 and 2.12 GeV have been observed in an analysis of the invariant-mass spectra of Δ++(1238)π-π0 and Δ++(1238)π-π- from π-p→π-pπ+π-π0 events in 4.5 GeV/c π-p interactions. An enhancement at 2.2 GeV is also seen with a dominant branching to the Δ(1238)ρ system. The 1.93 and 2.12 enhancements seem to be produced mainly through a ρ-meson exchange process. The 2.2 GeV enhancement seems to be produced diffractively and is considered to correspond to theG17(2190) state.

2 data tables

No description provided.

EXPONENTIAL FITS TO T-DISTRIBUTIONS.


Study of Electron - Positron Collisions at the Center-of-mass Energies of 27.4-{GeV} and 27.7-{GeV} at {PETRA}

Barber, D.P. ; Becker, U. ; Benda, H. ; et al.
Phys.Rev.Lett. 43 (1979) 901, 1979.
Inspire Record 141542 DOI 10.17182/hepdata.20739

This paper reports on the first results of the study of e+e− collisions at s=27.4 GeV and s=27.7 GeV at PETRA, using the 4π-sr electromagnetic and calorimetric detector MARK-J. We obtain an average R=σ(e+e−→hadrons)σ(e+e−→μ+μ−)=3.8±0.3 (statistical)±0.6 (systematic) and a relative R=1.0±0.2 between the two energies. The R values, the measured thrust distribution, and average spherocity show no evidence for the production of new quark flavors.

2 data tables

THE RELATIVE VALUE OF R BETWEEN THESE TWO ENERGIES IS 1.0 +- 0.2.

THRUST DISTRIBUTION (1/N)*DN/DTHRUST AT 13, 17 AND 27 GEV. THESE DATA ARE RATHER DETECTOR DEPENDENT.


Reaction $\pi^- p \to \omega n$ in the 15-{GeV}/$c$ - 40-{GeV}/$c$ Momentum Range

The Serpukhov-CERN collaboration Apel, W.D. ; Augenstein, K.H. ; Krüger, M. ; et al.
Lett.Nuovo Cim. 25 (1979) 493, 1979.
Inspire Record 142561 DOI 10.17182/hepdata.37383

None

7 data tables

DATA OBTAINED IN ASSUMPTION THAT RHO(MM=00,P=3,XYZ=SH)=1-2*RHO(MM=1-1,P=3,XYZ=SH).

INTEGRATED CROSS SECTION, INCLUDING SYSTEMATIC UNCERTAINTY IN ERRORS Axis error includes +- 15/15 contribution (DECAY-BR(BRN=OMEGA --> PI0 GAMMA,BR=0.088 +- 0.005)).

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