ISSN:
1434-6052
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract The cross section and jet rates ofZ 0 decays into photons and quarks are compared with matrix element Monte Carlos ofO(ααs). Good agreement is found between data and theoretical predictions. From the ratio of events with three jets plus a photon to those with two jets plus a photon, αs in first order is determined to be 0.176±0.010. Combining the cross section of final state photon events with the LEP average hadronic partial decay width of theZ 0, the widths of theZ 0 into up and down type quarks can be calculated. The results $$\begin{gathered} \Gamma _{u - type} = 242 \pm 46MeV; \hfill \\ \Gamma _{d - type} = 419 \pm 30MeV \hfill \\ \end{gathered} $$ are in good agreement with the standard model expectation. A comparison of the measured cross section as a function ofy cut with predictions of QCD shower models shows that, at the current level of accuracy ARIADNE and, to a lesser extent, HERWIG and JETSET can reproduce the measurement.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01557697