J/ψ production at CERN LEP:: Revisited and resummed -: art. no. 054016

We present the leading order differential and total rates for J/psi production at CERN LEP. By leading order we mean all terms of the form alpha(s)[alpha(s) log(M-Z(2)/M-psi(2))](n) and alpha(s)(n+1) log(1)(z(2))log(m)(M-Z(2)/M-psi(2)), (l+m=2n-1), in the regions z = 2E(psi)/M-Z similar to O(1) and z much less than 1, respectively. In the intermediate region we interpolate using the available data. This resummation eliminates the O[alpha(s)(M-psi)/alpha(s)(M-Z)]similar to 2 theoretical uncertainties in previous calculations. The log(z) resummation results in a suppression of the small z region due to coherent gluon emission. Comparing the zeroth moment with the LEP data we find the value for the effective octet matrix element to be [(O) over cap(8)(psi)(S-3(1))] = 0.019 GeV3. The theoretical uncertainties are substantially smaller than those from Fermilab Tevatron extractions. Using this value of the octet matrix element we make a prediction for the first moment of the differential rate and find that the resummed differential decay rate is in much better agreement with preliminary data than the color singlet result or the unresummed color octet prediction. [S0556-2821(99)04605-6].