Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Measurement of the strong coupling constant alpha-s from global event shape variables of hadronic Z decays
AU - Decamp, D.
AU - Finch, Alexander
AU - ALEPH Collaboration
PY - 1991
Y1 - 1991
N2 - An analysis of global event-shape variables has been carried out for the reaction e+e−→Z0→hadrons to measure the strong coupling constant αs. This study is based on 52 720 hadronic events obtained in 1989/90 with the ALEPH detector at the LEP collider at energies near the peak of the Z-resonance. In order to determine αs, second order QCD predictions modified by effects of perturbative higher orders and hadronization were fitted to the experimental distributions of event-shape variables. From a detailed analysis of the theoretical uncertainties we find that this approach is best justified for the differential two-jet rate, from which we obtain αs(MZ2) = 0.121 ± 0.002(stat.)±0.003(sys.)±0.007(theor.) using a renormalization scale . The dependence of αs(MZ2) on ω is parameterized. For scales mb<ω<MZ the result varies by −0.012+0.007.
AB - An analysis of global event-shape variables has been carried out for the reaction e+e−→Z0→hadrons to measure the strong coupling constant αs. This study is based on 52 720 hadronic events obtained in 1989/90 with the ALEPH detector at the LEP collider at energies near the peak of the Z-resonance. In order to determine αs, second order QCD predictions modified by effects of perturbative higher orders and hadronization were fitted to the experimental distributions of event-shape variables. From a detailed analysis of the theoretical uncertainties we find that this approach is best justified for the differential two-jet rate, from which we obtain αs(MZ2) = 0.121 ± 0.002(stat.)±0.003(sys.)±0.007(theor.) using a renormalization scale . The dependence of αs(MZ2) on ω is parameterized. For scales mb<ω<MZ the result varies by −0.012+0.007.
U2 - 10.1016/0370-2693(91)90278-X
DO - 10.1016/0370-2693(91)90278-X
M3 - Journal article
VL - 255
SP - 623
EP - 633
JO - Physics Letters B
JF - Physics Letters B
SN - 0370-2693
IS - 4
ER -