Has the Charm Deficit Really Vanished

摘要

Many experiments have observed charmed particles inclusively in e sup + e sup - annihilation, hadro-, photo-, and neutrino- production, and recently in the direct cascade process from B meson decay. The scale of these measurements is set largely by the branching ratios B(D sup 0 -> K sup - pi sup + ) and B(D sup + -> K sup - pi sup + pi sup + ). These branching fractions have been measured by attributing the enhancement in the total hadronic cross section at the psi(3770) resonance to D anti D production, and normalizing the rates for K sup - pi sup + and K sup - pi sup + pi sup + accordingly. These height measurements however exhibit a wide variance. Two years ago a new technique for measuring branching fractions was introduced by the Mark III, which largely avoided the cross section normalization. The result, however, yielded significantly larger values for all branching ratios while leaving their relative values unchanged. In turn, it created a problem for subsequent high statistics inclusive measurements of charm (in particular the continuum e sup + e sup - production rate and B cascade decay rates) where an approx.50% ''deficit'' of charm was claimed to exist by CLEO. With the rescaling downward by 24% (21%) of the Mark III D sup 0 (D sup + ) values, the so-called ''charm deficit'' is again addressed in this review. Also introduced here are new measurements from ARGUS and HRS which also directly address the issue of charm normalization with statistics comparable to other measurements. Finally, an attempt is made to understand the whole body of psi(3770) resonance data. 13 refs. (ERA citation 13:002177)