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Jet Fragmentation and {QCD} Models in $e^+ e^-$ Annihilation at $c$.m. Energies Between 12-{GeV} and 41.5-{GeV}

The TASSO collaboration Braunschweig, W. ; Gerhards, R. ; Kirschfink, F.J. ; et al.
Z.Phys.C 41 (1988) 359-373, 1988.
Inspire Record 263859 DOI 10.17182/hepdata.15531

The large amount of data accumulated by the TASSO detector at 35 GeV c.m. energy has been compared with the predictions of the latest generation of perturbative QCD+fragmentation models. By adjustment of the arbitrary parameters of these models, a very good description of the global properties of hadronic events was obtained. No one model gave the best description of all features of the data, each model being better than the others for some observables and worse in other quantities. We interpret these results in terms of the underlying QCD and hadronisation schemes. The trends of the data across the energy range 12.0≦W≦41.5 GeV are generally well reproduced by the models with the parameters optimised at 35 GeV.

11 data tables match query

The errors include the statistical error and that from the correction procedure.

The errors include the statistical error and that from the correction procedure.

The errors include the statistical error and that from the correction procedure.

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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

No description provided.

No description provided.


Measurement of the Radiative Width of the $\eta^\prime$ (958) in Two Photon Interactions

The TASSO collaboration Althoff, M. ; Braunschweig, W. ; Kirschfink, F.J. ; et al.
Phys.Lett.B 147 (1984) 487-492, 1984.
Inspire Record 203795 DOI 10.17182/hepdata.30481

The reaction e + e − →e + e − η ′(958) has been observed by detecting the final state π + π − γ . The two-photon width of the η′ has been measured to be Γ ( η ′→ γγ ) = 5.1±0.4±0.7 keV. A search for the ι (1440) has been made in the ϱ 0 γ final state. An upper limit has been obtained for the product Γ ( ι (1440) → γ ) gg ), B ( ι → ϱ 0 γ ) < 1.5 keV (95%CL).

1 data table match query

No description provided.


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.

2 data tables match query

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

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


Observation of the Reaction $\gamma \gamma \to p \bar{p} \pi^+ \pi^-$

The TASSO collaboration Althoff, M. ; Braunschweig, W. ; Kirschfink, F.J. ; et al.
Phys.Lett.B 142 (1984) 135-140, 1984.
Inspire Record 199848 DOI 10.17182/hepdata.30532

Production of the p p π + π − final state by two-photon scattering was observed. The cross section for γγ→p p π + π − was determined assuming phase space production. No evidence was found for the production or formation of resonances. Upper limits are given for Λ and Δ pair production, for production of p p ϱ 0 and for the two-photon excitation of c c bound states.

1 data table match query

No description provided.


Observation of F Meson Production in High-energy $e^+ e^-$ Annihilation

The TASSO collaboration Althoff, M. ; Braunschweig, W. ; Kirschfink, F.J. ; et al.
Phys.Lett.B 136 (1984) 130-134, 1984.
Inspire Record 194774 DOI 10.17182/hepdata.30586

Production of the F meson by e + e − annihilation at high energies has been obsrved in the ϕπ final state with a mass of 1.975 ± 0.009 ± 0.010 GeV and a width consistent with the mass resolution. The yield of F production times branching ratio relative to μ pair production is R F ( x ⩾ 0.3) B (F ± → ϕπ ± ) = 0.061 ± 0.012 ± 0.018.

2 data tables match query

No description provided.

CROSS BETWEEN X BRANCHING RATIO DETERMINATION. EXTRAPOLATION BELOW X=0.3 IS USED.


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.

2 data tables match query

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.

No description provided.


Observation of Xi-, Anti-xi- Production in $e^+ e^-$ Annihilation

The TASSO collaboration Althoff, M. ; Braunschweig, W. ; Gather, K. ; et al.
Phys.Lett.B 130 (1983) 340-344, 1983.
Inspire Record 192072 DOI 10.17182/hepdata.30636

We present evidence for the production of Ξ· − , Ξ − in e + e − annihilation into hadrons. Our measurements yields: 0.026 ± 0.008 (stat.) ± 0.009 (syst.) Ξ − , Ξ − per hadronic event at W ∼ 34 GeV. Using our previous measurements of Λ, Λ and p, p production we obtain the relative yields (Ξ − , Ξ − /(Λ, Λ = 0.087 ± 0.03 ( stat. ) ± 0.03 ( syst. ) and (Ξ − , Ξ − /( p , p = 0.033 ± 0.011 ( stat. ) ± 0.011 ( syst. ) .

2 data tables match query

TOTAL YIELD PER HADRONIC EVENT AND COMPARISON WITH PREVIOUS TASSO MEASUREMENTS OF OTHER BARYONS PRODUCTION. EXTRAPOLATION HAS BEEN MADE TO MOMENTA LOWER THAN IN THE EXPERIMENTAL RANGE.

NUMERICAL VALUES SUPPLIED BY P. JOOS.


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

No description provided.

No description provided.

Corrected 3 jet rate with YCUT=0.08.


Evidence for Local Compensation of Baryon Number in $e^+ e^-$ Annihilation

The TASSO collaboration Althoff, M. ; Braunschweig, W. ; Kirschfink, F.J. ; et al.
Phys.Lett.B 139 (1984) 126-132, 1984.
Inspire Record 199469 DOI 10.17182/hepdata.27109

We have studied at CM energies of 14, 22 and 30–36.7 GeV e + e − annihilation events in which the hadronic final state contains both a proton and an antiproton in the momentum range 1.0 < p < GeV/ c . We find that such pairs are produced predominantly in the same jet and conclude that baryon-antibaryon production is dominated by a mechanism involving local compensation of baryon number.

2 data tables match query

BACKGROUND SUBTRACTED DATA.

BACKGROUND SUBTRACTED DATA.