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Experimental Study of Jet Masses in $e^+ e^-$ Annihilation at $c$.m. Energies Between 12-{GeV} and 43.5-{GeV}

The TASSO collaboration Braunschweig, W. ; Gerhards, R. ; Kirschfink, F.J. ; et al.
Z.Phys.C 45 (1989) 11, 1989.
Inspire Record 279165 DOI 10.17182/hepdata.15297

Data on jet masses, resulting from the decomposition ofe+e− hadronic final states into two hemispheres, are presented at centre of mass energies between 12 and 43.5 GeV. Comparisons are made with bareO(αs2) QCD predictions as well as with QCD based fragmentation models. Values for αs and\(\Lambda _{\overline {MS} } \) are determined, both with and without hadronization effects included. Upper and lower limits for\(\Lambda _{\overline {MS} } \) independent of fragmentation models have been determined to be 0.480±0.025 GeV and 0.047±0.007 GeV respectively.

3 data tables match query

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A Measurement of Muon Pair Production in $e^+ e^-$ Annihilation at Center-of-mass Energies 35-{GeV} $\le \sqrt{s} \le$ 46.8-{GeV}

The TASSO collaboration Braunschweig, W. ; Gerhards, R. ; Kirschfink, F.J. ; et al.
Z.Phys.C 40 (1988) 163-170, 1988.
Inspire Record 261668 DOI 10.17182/hepdata.1897

The reactione+e−→µ+µ− has been studied at centre of mass energies between 35.0 and 46.8 GeV using the TASSO detector at PETRA. We present measurements of the forward-backward charge asymmetry (Aμμ) and cross section σμμ for this reaction at three energies. At 35.0 GeV we obtain a cross section relative to the QED prediction ofRμμ=σμμ/σo=0.932±0.018±0.044 andAμμ=(−10.6−2.3+2.2±0.5)%. At 38.3 GeV we findRμμ=0.951±0.072−0.057+0.063 andAμμ=(+1.7−8.6+8.5±0.5)%. At 43.6 GeV we measureRμμ=0.921±0.037±0.055 andAμμ=(−17.6−4.3+4.4±0.5)%. Our results are in good agreement with the predictions of the standard model. Including previous TASSO data we present improved determinations of muonic electroweak parameters. We also report on lower limits of possible contributions from contact interactions.

7 data tables match query

If only one error is given, this is the sum of the statistical and systematic errors in quadrature.

The data are corrected for 'reduced QED' radiative corrections. Statistical errors only.

The data are corrected for 'reduced QED' radiative corrections. Statistical errors only.

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Charged Multiplicity Distributions and Correlations in e+ e- Annihilation at PETRA Energies

The TASSO collaboration Braunschweig, W. ; Gerhards, R. ; Kirschfink, F.J. ; et al.
Z.Phys.C 45 (1989) 193, 1989.
Inspire Record 277658 DOI 10.17182/hepdata.1499

We report on an analysis of the multiplicity distributions of charged particles produced ine+e− annihilation into hadrons at c.m. energies between 14 and 46.8 GeV. The charged multiplicity distributions of the whole event and single hemisphere deviate significantly from the Poisson distribution but follow approximate KNO scaling. We have also studied the multiplicity distributions in various rapidity intervals and found that they can be well described by the negative binomial distribution only for small central intervals. We have also analysed forward-backward multiplicity correlations for different energies and selections of particle charge and shown that they can be understood in terms of the fragmentation properties of the different quark flavours and by the production and decay of resonances. These correlations are well reproduced by the Lund string model.

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RATIO of MULT/DISPERSION for the whole event to that for the single hemisphere data.

Complete event multiplicities.

Single hemisphere multiplicities.

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An Improved Measurement of Electroweak Couplings From $e^+ e^- \to e^+ e^-$ and $e^+ e^- \to \mu^+ \mu^-$

The TASSO collaboration Althoff, M. ; Braunschweig, W. ; Kirschfink, F.J. ; et al.
Z.Phys.C 22 (1984) 13, 1984.
Inspire Record 193787 DOI 10.17182/hepdata.2111

We present an analysis of electroweak leptonic couplings from high statistics experiments on Bhabha scattering and μ pair production at an energy of 34.5 GeV. The forward-backward charge asymmetry of the μ pairs was measured to be −0.098±0.023±0.005. The data were found to agree well with the standard theory of electroweak interaction giving sin2θW=0.27±0.07. The leptonic weak couplings were determined to begv=0.000±0.170 andgA=−0.481±0.055. The data were also used to investigate a class of composite models for leptons.

2 data tables match query

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Pion, Kaon and Proton Cross-sections in $e^+ e^-$ Annihilation at 34-{GeV} and 44-{GeV} Center-of-mass Energy

The TASSO collaboration Braunschweig, W. ; Gerhards, R. ; Kirschfink, F.J. ; et al.
Z.Phys.C 42 (1989) 189, 1989.
Inspire Record 267755 DOI 10.17182/hepdata.1500

The inclusive production of π± andK± mesons and of protons and antiprotons ine+e− annihilations has been measured at 34 GeV and 44 G

18 data tables match query

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Measurement of r and Search for the Top Quark in e+ e- Annihilation Between 39.8-GeV and 45.2-GeV

The TASSO collaboration Althoff, M. ; Braunschweig, W. ; Kirschfink, F.J. ; et al.
Phys.Lett.B 138 (1984) 441-448, 1984.
Inspire Record 199468 DOI 10.17182/hepdata.6655

e + e − annihilation into hadrons was studied at CM energies between 39.8 and 45.2 GeV and a search was made for new heavy quarks. No evidence was found for the existence of a narrow state excluding the possible existence of the lowest vector toponium state in this mass range. A search for continuum production of heavy quarks led to lower mass limits for new quarks of 22.0 GeV ( e Q = 2 3 ) and 21.0 GeV ( e Q = 1 3 ). Quarks are found to be pointlike, the corresponding mass parameter being larger than 288 GeV. A fit of the QCD and the electroweak contributions to R = σ tot / σ μμ yielded sin 2 θ W = 0.30 −0.07 +0.23 .

3 data tables match query

STATISTICAL ERRORS ONLY. NUMERICAL VALUES OF DATA TAKEN FROM PREPRINT.

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Experimental Test of the Flavor Independence of the Quark - Gluon Coupling Constant

The TASSO collaboration Althoff, M. ; Braunschweig, W. ; Kirschfink, F.J. ; et al.
Phys.Lett.B 138 (1984) 317-324, 1984.
Inspire Record 199470 DOI 10.17182/hepdata.6609

Reconstruction of charged D ∗ 's produced inclusively in e + e −. annihilation at CM energies near 34.4 GeV is accomplished in the decay modes D ∗ + → D 0 π + → K − gp + π 0 π + and D ∗ + → D 0 π + → K − gp + π − π + π + and their charge conjugates. Using these and previously reported D ∗ + → D 0 π + → K − gp + π + and D ∗ + → D 0 π + → K − gp + π + + missing π 0 channels we present evidence for hard gluon bremsstrahlung from charm quarks and show that the ratio of the quark-gluon coupling constant of charm quarks to the coupling constant obtained in the average hadronic event, α s c α rms = 100 ± 0.20 ± 1.20 . Our result provides evidence that the quark-gluon coupling constant is independent of flavor.

2 data tables match query

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Analysis of Multi - Jet Final States in $e^+ e^-$ Annihilation

The TASSO collaboration Braunschweig, W. ; Gerhards, R. ; Kirschfink, F.J. ; et al.
Phys.Lett.B 214 (1988) 286-294, 1988.
Inspire Record 261486 DOI 10.17182/hepdata.29878

Data accumulated by the TASSO detector across the whole range of energies spanned at PETRA, 12⩽ s ⩽46.8 GeV , have been analysed in terms of cluster algorithms. Using parameters optimised at 35 GeV CM energy, three perturbative QCD+fragmentation models were compared with the data. The O( α s 2 ) model gives too few 4,5- cluster events, implying that higher order QCD contributions are required to describe the data. The parton cascade model, incorporating many orders in perturbation theory, gives a better description of the rates of ⩾ 4 clusters, but shows a lack of hard gluon emission by giving too few 3-, and too many 2-cluster events. When hard gluon emission is taken into account, by the cascade model incorporating the O( α s ) matrix element, all cluster rates are reproduced well. All the models describe the trend of the evolution of the cluster rates between 〈 s 〉 = 14 and 43.8 GeV. We find that the rate of 3-jet events seen in the data decreases as s increases in a manner consistent with the Q 2 dependence of α s as predicted by QCD.

3 data tables match query

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Corrected 3 jet rate with YCUT=0.08.


Inclusive Electron Production From Heavy Quarks in $e^+ e^-$ Annihilation at 34.6-{GeV} Center-of-mass Energy

The TASSO collaboration Althoff, M. ; Braunschweig, W. ; Kirschfink, F.J. ; et al.
Phys.Lett.B 146 (1984) 443-449, 1984.
Inspire Record 202782 DOI 10.17182/hepdata.30507

The production of electrons by bottom and charm hadrons has been studied in e + e − annihilation at 34.6 GeV center of mass energy. It is observed that the b quark fragmentation function is peaked at large values of the scaling variable z with 〈 z b 〉 = 0.84 +0.15 + 0.15 −0.10 − 0.11 . For c quarks 〈 z c 〉 = 0.57 +0.10 + 0.05 −0.09 − 0.06 is observed. A forward-backward charge asymmetry of A = −0.25 ± 0.22 was measured in b production.

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THE VALUE OF ASYMMETRY WAS DETERMINED USING A SAMPLE OF PROMPT ELECTRONS.

THE VALUE OF ASYMMETRY WAS DETERMINED USING A SAMPLE OF PROMPT ELECTRONS.


Properties of Charm Jets Produced in $e^+ e^-$ Annihilation Near 34-{GeV}

The TASSO collaboration Althoff, M. ; Braunschweig, W. ; Kirschfink, F.J. ; et al.
Phys.Lett.B 135 (1984) 243-249, 1984.
Inspire Record 194050 DOI 10.17182/hepdata.30600

D ∗± production via e + e − → D ∗± X was studied at CM energies near 34 GeV. The charged particles produced in the hemisphere opposite to that of the D ∗ were used to investigate the fragmentation of charm jets. All spectra studied show a close similarity between the charm jet and the average jet obtained by summing over all quark flavours. The spectra of particles produced in the D ∗ hemisphere were used to study separately first rank and higher rank fragmentation.

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THE C-JET IS THE JET IN THE HEMISPHERE OPPOSITE TO THAT CONTAINING THE D* MESON. DIVISION IS MADE BY A PLANE PERPENDICULAR TO THE THRUST AXIS.