The production of W+W- pairs is analysed in a data sample collected by ALEPH at a mean centre-of-mass energy of 188.6 GeV, corresponding to an integrated luminosity of 174.2 pb(-1). Cross sections are given for different topologies of W decays into leptons or hadrons. Combining all final states and assuming Standard Model branching fractions, the total W-pail cross section is measured to be 15.71 +/- 0.34(stat.) +/- 0.18(syst.) pb. Using also the W-pair data samples collected by ALEPH at lower centre-of-mass energies, the decay branching fraction of the W boson into hadrons is measured to be B(W --> hadrons) = 66.97 +/- 0.65(stat.) +/- 0.32(syst.)%, allowing a determination of the CKM matrix element /V-cs/ = 0.951 +/- 0.030(stat,) +/- 0.015(syst.). (C) 2000 Elsevier Science B.V. All rights reserved. RI ANTONELLI, ANTONELLA/C-6238-2011; Jones, Roger/H-5578-2011; Passalacqua, Luca/F-5127-2011; Murtas, Fabrizio/B-5729-2012; O'Shea, Val/G-1279-2010
Measurement of W-pair production in e(+)e(-) collisions at 189 GeV
TRICOMI, Alessia Rita;
2000-01-01
Abstract
The production of W+W- pairs is analysed in a data sample collected by ALEPH at a mean centre-of-mass energy of 188.6 GeV, corresponding to an integrated luminosity of 174.2 pb(-1). Cross sections are given for different topologies of W decays into leptons or hadrons. Combining all final states and assuming Standard Model branching fractions, the total W-pail cross section is measured to be 15.71 +/- 0.34(stat.) +/- 0.18(syst.) pb. Using also the W-pair data samples collected by ALEPH at lower centre-of-mass energies, the decay branching fraction of the W boson into hadrons is measured to be B(W --> hadrons) = 66.97 +/- 0.65(stat.) +/- 0.32(syst.)%, allowing a determination of the CKM matrix element /V-cs/ = 0.951 +/- 0.030(stat,) +/- 0.015(syst.). (C) 2000 Elsevier Science B.V. All rights reserved. RI ANTONELLI, ANTONELLA/C-6238-2011; Jones, Roger/H-5578-2011; Passalacqua, Luca/F-5127-2011; Murtas, Fabrizio/B-5729-2012; O'Shea, Val/G-1279-2010I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.