Geiregat, D.
ALPHAS
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A Determination of the Total Width of the $\Upsilon$ (9.46) Meson

Albrecht, H. ; Childers, R. ; Darden, C.W. ; et al.
Phys.Lett.B 93 (1980) 500-504, 1980.
Inspire Record 153029 DOI 10.17182/hepdata.6334

Using the DASP detector at the DESY storage ring DORIS we have continued measuring e + e − annihilations near and on the ϒ(9.46) resonance. From the cross sections for e + e − → μ + μ − and e + e − → hadrons we obtain a μ + μ − branching ratio for the ϒ(9.46) of (2.9 ± 1.3 ± 0.5) %, a leptonic width г ee = (1.35 ± 0.11 ± 0.22) keV and a total width of (47 −15 +37 keV.

2 data tables
Table 1

VISIBLE HADRONIC CROSS SECTION. PEAK VALUE AT UPSILON IS 10.1 +- 0.7 NB.

Table 2

No description provided.


Observation of Planar Three Jet Events in e+ e- Annihilation and Evidence for Gluon Bremsstrahlung

The JADE collaboration Bartel, W. ; Canzler, T. ; Cords, D. ; et al.
Phys.Lett.B 91 (1980) 142-147, 1980.
Inspire Record 143985 DOI 10.17182/hepdata.6339

Topological distributions of charged and neutral hadrons from the reaction e + e − → multihadrons are studied at √ s of about 30 GeV. An excess of planar events is observed at a rate which cannot be explained by statistical fluctuations in the standard two-jet process. The planar events, mostly consisting of a slim jet on one side and a broader jet on the other, are shown actually to possess three-jet structure by demonstrating that the broader jet itself consists of two collinear jets in its own rest system. Detailed agreement between data and predictions is obtained if the process e + e − →q q ̄ g is taken into account. This strongly suggests gluon bremsstrahlung as the origin of the planar three-jet events. By comparison of the data with the qq̄g-model we obtain a value for the strong coupling constant of α S ( q 2 = 0.17 ± 0.04.

2 data tables
Table 1

THRUST AND PLANARITY DISTRIBUTIONS. FINAL (BETTER) THRUST DISTRIBUTIONS WITH DETECTOR CORRECTIONS TO BE PUBLISHED LATER.

Table 2

No description provided.


Tests of Quantum Chromodynamics and a Direct Measurement of the Strong Coupling Constant $\alpha_S$ at $\sqrt{s}=30$-{GeV}

Barber, D.P. ; Becker, U. ; Benda, H. ; et al.
Phys.Lett.B 89 (1979) 139-144, 1979.
Inspire Record 143680 DOI 10.17182/hepdata.6483

We report the measurement of the reaction e + + e − → hadronic jets at a center-of-mass energy √ s =30 GeV using the MARK-J detector at PETRA. By measuring the energy and angular distribution of both neutrals and charged particles we were able to isolate unambiguously the three-jet events in a kinematic region where the backgrounds from q q and phase space contributions and other processes are small. Various comparisons of the data with quantum chromodynamics were made. The relative yield of three-jet events and the shape distribution of the events enable us to determine α s = 0.23 ± 0.02 (statistical error) with a systematic error of ± 0.04.

2 data tables
Table 1

OBLATENESS AND THRUST DISTRIBUTIONS FOR NARROW AND BROAD JETS AT 30 GEV. THESE DATA ARE SOMEWHAT ANALYSIS AND DETECTOR DEPENDENT.

Table 2

No description provided.