After the successes the OPE description has scored in describing Bˉ→lνˉXc decays, we need to study what can be said about the composition
of the hadronic final state Xc. The same OPE treatment yields sum rules
implying the dominance of jq=3/2 charm states in Xc over their
jq=1/2 counterparts. This prediction is supported by other general arguments
as well as quark model calculations. At present it is unclear to which degree
data conform to these predictions. More experimental information is essential.
We want to ask our experimental colleagues for a redoubled effort to establish,
which hadronic configurations -- D/D∗+π,D/D∗+2π,... -- make up
Γ(Bˉ→lνˉXc) beyond Bˉ→lνˉD/D∗, what
their quantum numbers are and their mass distributions. The latter is most
relevant for the determination of hadronic mass moments in Bˉ→lνˉXc. Since all this will require considerable effort on their part, we
want to explain the theoretical issues involved, why they carry `gravitas' --
i.e. are weighty -- and why a better understanding of them will be of
significant value. In this brief memo we sketch the underlying arguments based
on heavy quark theory, the OPE, a special class of quark models and lattice QCD
in a nutshell. After summarizing the experimental situation we conclude with
two lists, namely one with measurements that need to be done and one with items
of theoretical homework. Some of the latter can be done by employing existing
theoretical tools, whereas others need new ideas.Comment: 13 pages, no figure