Measurement of the longitudinal and transverse cross-section in e+ e- annihilation at s**(1/2) = 35-GeV to 44-GeV.

The JADE collaboration Blumenstengel, M. ; Biebel, O. ; Movilla Fernandez, P.A. ; et al.
Phys.Lett.B 517 (2001) 37-46, 2001.
Inspire Record 558568 DOI 10.17182/hepdata.37882

An investigation of the polar angle distribution of charged hadrons is presented using data taken by the JADE experiment at the PETRA e^+e^- collider at centre-of-mass energies of 35 and 44 GeV. From fits to the polar angle distribution the longitudinal, sigma_L, and transverse, sigma_T, cross-section relative to the total hadronic are determined at an average energy scale of 36.6 GeV. The results are sigma_L/sigma_tot = 0.067 +/- 0.013, sigma_T/sigma_tot = 0.933 -/+ 0.013 where total errors are given and the results are exactly anti-correlated. Using the next-to-leading order QCD prediction for the longitudinal cross-section, the value alpha_S(36.6 GeV) = 0.150 +/- 0.025 of the strong coupling constant is obtained in agreement with the world average value of alpha_S evolved to an energy scale of 36.6 GeV.

3 data tables

The distribution oF Q*COS(THETA) where Q is the charge of the individual hadron and THETA is the polar angle between the direction of the incoming E- beam and the outgoing hadron. The data are corrected for detector effects.

Value of the longitudinal cross section relative to the total cross section.

Value of the strong coupling constant ALPHAS deduced from the measurements. The second DSYS error is the uncertainty on the renormalisation scale.


Tests of the standard model and constraints on new physics from measurements of fermion pair production at 189-GeV at LEP

The OPAL collaboration Abbiendi, G. ; Ackerstaff, K. ; Alexander, G. ; et al.
Eur.Phys.J.C 13 (2000) 553-572, 2000.
Inspire Record 504989 DOI 10.17182/hepdata.49123

Cross-sections and angular distributions for hadronic and lepton pair final states in e+e- collisions at a centre-of-mass energy near 189 GeV, measured with the OPAL detector at LEP, are presented and compared with the predictions of the Standard Model. The results are used to measure the energy dependence of the electromagnetic coupling constant alpha_em, and to place limits on new physics as described by four-fermion contact interactions or by the exchange of a new heavy particle such as a sneutrino in supersymmetric theories with R-parity violation. A search for the indirect effects of the gravitational interaction in extra dimensions on the mu+mu- and tau+tau- final states is also presented.

9 data tables

Hadronic cross section.

The cross sections for hadronic, and muon- and tau-pair production in the two sprime/s regions.

The cross sections for electron -pair production with various angular cuts.

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Tests of the standard model and constraints on new physics from measurements of fermion pair production at 183-GeV at LEP

The OPAL collaboration Abbiendi, G. ; Ackerstaff, K. ; Alexander, G. ; et al.
Eur.Phys.J.C 6 (1999) 1-18, 1999.
Inspire Record 473699 DOI 10.17182/hepdata.49337

Cross-sections for hadronic, b-bbar and lepton pair final states in e+e- collisions at sqrt(s) = 183 GeV, measured with the OPAL detector at LEP, are presented and compared with the predictions of the Standard Model. Forward-backward asymmetries for the leptonic final states have also been measured. Cross-sections and asymmetries are also presented for data recorded in 1997 at sqrt(s) = 130 and 136 GeV. The results are used to measure the energy dependence of the electromagnetic coupling constant alpha_em, and to place limits on new physics as described by four-fermion contact interactions or by the exchange of a new heavy particle such as a leptoquark, or of a squark or sneutrino in supersymmetric theories with R-parity violation.

21 data tables

No description provided.

The contribution of interference between initial- and final-state radiationhas been removed.

The contribution of interference between initial- and final-state radiationhas been removed.

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