Penguin diagrams, charmless B decays, and the ''missing charm puzzle''

We calculate the contributions of penguin diagrams with internal u or c quarks to various inclusive charmless B-decay rates. Further we analyze the influence of the chromomagnetic dipole operator Q(8) on these rates. We find that the rates corresponding to (B) over bar --> X-u(u over bars$), (B) over bar --> X-d(d over bars$), (B) over bar --> X-s(s over bars$), (B) over bar --> X-s(s over bard$), and (B) over bar --> X d(d) over bard$ are dominated by the new penguin contributions. The contributions of Q(8) sizably diminish these rates. Despite an increase of the total charmless decay rate by 36%, the new contributions are not large enough to explain the charm deficit observed by ARGUS and CLEO. We predict n(c) = 1.33+/-0.06 for the average number of charmed particles per B decay in the standard model. Then the hypothesis of an enhancement of the chromomagnetic dipole coefficient C-8 by new physics contributions is analyzed. We perform a model-independent fit of C-8 to the experimental data. If the CKM structure of the new physics contribution is the same as in the standard model, \C-8(MW)\ must be enhanced by a factor of 9 to 16 in order to explain the observed charm deficit. [S0556-2821(97)07623-6].