A new measurement of the forward-backward asymmetry in Z -> b bbar decays is presented. Hadrons from b decays are tagged using their long lifetimes. The b quark charge and direction are reconstructed with a hemisphere charge algorithm. The asymmetry and reconstructed b hemisphere charge are measured in the 69 pb(-1) of data collected by ALEPH during 1991, 1992 and 1993. They are used to extract sin^2(theta(w)eff), which is determined to be 0.2315 +/- 0.0016 (stat.) +/- 0.0009 (syst.), corresponding to an A(FB)b of 0.00992 +/- 0.0084 (stat.) +/- 0.0046 (stat.).
A Measurement of A(FB)(b) In Lifetime Tagged Heavy Flavor Z Decays
BATIGNANI, GIOVANNI;CIOCCI, MARIA AGNESE;FERRANTE, ISIDORO;FIDECARO, FRANCESCO;FORTI, FRANCESCO;GIORGI, MARCELLO;MESSINEO, ALBERTO MARIA;RIZZO, GIULIANA;TONELLI, GUIDO EMILIO;G. TRIGGIANI;
1994-01-01
Abstract
A new measurement of the forward-backward asymmetry in Z -> b bbar decays is presented. Hadrons from b decays are tagged using their long lifetimes. The b quark charge and direction are reconstructed with a hemisphere charge algorithm. The asymmetry and reconstructed b hemisphere charge are measured in the 69 pb(-1) of data collected by ALEPH during 1991, 1992 and 1993. They are used to extract sin^2(theta(w)eff), which is determined to be 0.2315 +/- 0.0016 (stat.) +/- 0.0009 (syst.), corresponding to an A(FB)b of 0.00992 +/- 0.0084 (stat.) +/- 0.0046 (stat.).File in questo prodotto:
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