Update of the Inclusive Production of the !(782) Vector Meson in Hadronic Decays of the Z

The inclusive production of the !(782) vector meson in hadronic Z decays is studied and compared to model predictions. The analysis is based on 1,005,535 hadronic Z decays recorded by the ALEPH detector in the 1992 and 1993 running periods of LEP providing an update to the previous published result. Decays of the ! ! + ? 0 are reconstructed for x p > 0:05, where x p = p=p beam. For this momentum range the ! production rate is measured to be 0:633 0:025 stat 0:056 sys per event (previous result 0:637 0:034 stat 0:074 sys per event). An extrapolation to x p = 0 yields a total production rate of 1:0610:041 stat 0:093 sys 0:042 extrap per event (previous result 1:066 0:058 stat 0:124 sys 0:044 extrap per event). As no previous ALEPH note has been written the analysis is describe here in some detail. A more complete account of this analysis can be found in the PhD thesis of the same name.