Berger, Edmond L.
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On the Model Dependence of the Determination of the Strong Coupling Constant in Second Order {QCD} From $e^+ e^-$ Annihilation Into Hadrons

The CELLO collaboration Behrend, H.J. ; Fenner, H. ; Schachter, M.J. ; et al.
Phys.Lett.B 138 (1984) 311-316, 1984.
Inspire Record 195332 DOI 10.17182/hepdata.6634

Hadronic events obtained with the CELLO detector at PETRA are compared with second order QCD predictions using different models for the fragmentation of quarks and gluons into hadrons. We find that the model dependence in the determination of the strong coupling constant persists when going from first to second order QCD calculations.

3 data tables
Table 1

ASYMMETRY FOR DATA CORRECTED WITH IF MODEL (ALPHA-S=0.12).

Table 2

ASSYMETRY FOR DATA CORRECTED WITH SF MODEL (ALPHA-S=0.19).

Table 3

No description provided.


Electroweak Coupling Constants in the Leptonic Reactions e+ e- ---> e+ e- and e+ e- ---> mu+ mu- and Search for Scalar Leptons

The TASSO collaboration Brandelik, R. ; Braunschweig, W. ; Gather, K. ; et al.
Phys.Lett.B 117 (1982) 365-371, 1982.
Inspire Record 178495 DOI 10.17182/hepdata.6669

A high statistics experiment was performed on Bhabha scattering at energies between 14 and 34 GeV. Good agreement with QED was observed. The combined data on Bhabha scattering and μ pair production were found to agree with the standard theory of electroweak interaction giving sin 2 θ = 0.27 −0.07 +0.06 . Assuming for the Z 0 mass a value of 90 GeV the leptonic weak coupling constants were determined to g V 2 = −0.04 ± 0.06 and g A 2 = 0.35 ± 0.09. A search for scalar leptons sets lower limits on the mass of scalar electrons of M s e > 16.6 GeV and of scalar muons of M s μ > 16.4 GeV.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


Test of {QED} in $e^+ e^-$ Annihilation at Energies Between 12-{GeV} and 31.6-{GeV}

The TASSO collaboration Brandelik, R. ; Braunschweig, W. ; Gather, K. ; et al.
Phys.Lett.B 94 (1980) 259-265, 1980.
Inspire Record 153127 DOI 10.17182/hepdata.45228

We have measured the reactions e + e − → e + e − → μ + μ − and e + e − → γγ at c.m. energies between 12 and 31.6 GeV. Excellent agreement with the predictions of QED has been found, resulting in cut off parameters Λ + > 112 GeV and Λ − > 139 GeV for the first process and Λ + > 34 GeV and Λ − > 42 GeV (95% c.1.) for the last one. A limit on the Weinberg angle of sin 2 θ W < 0.55 (95% c.1.) has been obtained.

3 data tables
Table 1

SIG(C=QED) QED predictions for the cross sections. Only statistical errors are given.

Table 2

SIG(C=QED) QED predictions for the cross sections. Only statistical errors are given.

Table 3

SIG(C=QED) QED predictions for the cross sections. Only statistical errors are given.


Measurement of e+ e- ---> e+ e- and e+ e- ---> mu+ mu- at SPEAR

Augustin, J.E. ; Boyarski, A. ; Breidenbach, Martin ; et al.
Phys.Rev.Lett. 34 (1975) 233, 1975.
Inspire Record 91755 DOI 10.17182/hepdata.21210

The reactions e+e−→e+e− and e+e−→μ+μ− have been measured at center-of-mass energies 3.0, 3.8, and 4.8 GeV and production angles of 50°<θ<130° over all azimuthal angles. Agreement with quantum electrodynamics is excellent. New limits for cutoff parameters in quantum-electrodynamic-breakdown models are given.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


Electron-Positron Elastic Scattering at 5-GeV Center-Of-Mass Energy

Newman, H. ; Averill, R. ; Eshelman, J. ; et al.
Phys.Rev.Lett. 32 (1974) 483, 1974.
Inspire Record 744 DOI 10.17182/hepdata.21306

We have measured the cross section, the distribution of scattering angles, and the distribution of noncoplanarity angles for electron-positron elastic scattering at 5 GeV c. m. energy. An analysis based on 230 events with scattering angles between 50 and 130° yields a ratio of the experimental to theoretical quantum-electrodynamic cross section of 1.03 ± 0.09. The scattering-angle and noncoplanarity-angle distributions are also found to be in excellent agreement with the quantum-electrodynamic predictions.

1 data table
Table 1

No description provided.


Muon pair production by electron-positron collisions in the gev region

Borgia, B. ; Ceradini, F. ; Conversi, M. ; et al.
Lett.Nuovo Cim. 3S2 (1972) 115-120, 1972.
Inspire Record 77432 DOI 10.17182/hepdata.37904

None

1 data table
Table 1

CONST(NAME=EXP/THEORY) is the experimental numbers divided by the theoretical predictions.