Structure of e{sup +}e{sup {minus}} {r_arrow}b anti-b Events and Improved Limits on the Anomalous Chromomagnetic Coupling of the b-quark

摘要

The structure of e{sup +}e{sup {minus}} --> b anti-b g events was studied using Z{sup 0} decays recorded in the SLD experiment at SLAC. Three-jet final states were selected and the CCD-based vertex detector was used to identify two of the jets as b or anti-b. Distributions of the gluon energy and polar angle were measured over the full kinematic range, and compared with perturbative QCD predictions. The energy distribution is potentially sensitive to an anomalous b chromomagnetic moment kappa. The authors measured kappa to be consistent with zero and set limits on its value, {minus}0.11 < kappa < 0.08 at 95% c.l. (preliminary).