  In previous work it has been shown that, either from a sum rule for the
subleading Isgur-Wise function $\xi_3(1)$ or from a combination of Uraltsev and
Bjorken SR, one infers for $P$-wave states $|\tau_{1/2}(1)| \ll
|\tau_{3/2}(1)|$. This implies, in the heavy quark limit of QCD, a hierarchy
for the {\it production} rates of $P$-states $\Gamma(\bar{B}_d \to D ({1 \over
2}) \ell \nu) \ll \Gamma(\bar{B}_d \to D ({3 \over 2}) \ell \nu)$ that seems at
present to be contradicted by experiment. It was also shown that the decay
constants of $j = {3 \over 2}$ $P$-states vanish in the heavy quark limit of
QCD, $f_{3/2}^{(n)} = 0$. Assuming the {\it model} of factorization in the
decays $\bar{B}_d \to \bar{D}_s^{**}D$, one expects the opposite hierarchy for
the {\it emission} rates $\Gamma(\bar{B}_d \to \bar{D}_s ({3 \over 2}) D) \ll
\Gamma(\bar{B}_d \to \bar{D}_s ({1 \over 2}) D)$, since $j = {1 \over 2}$
$P$-states are coupled to vacuum. Moreover, using Bjorken SR and previously
discovered SR involving heavy-light meson decay constants and IW functions, one
can prove that the sums $\sum\limits_n ({f^{(n)} \over f^{(0)}})^2$,
$\sum\limits_n ({f_{1/2}^{(n)} \over f^{(0)}})^2$ (where $f^{(n)}$ and
$f_{1/2}^{(n)}$ are the decay constants of $S$-states and $j = {1\over 2}$
$P$-states) are divergent. This situation seems to be realized in the
relativistic quark models \`a la Bakamjian and Thomas, that satisfy HQET and
predict decays constants $f^{(n)}$ and $f_{1/2}^{(n)}$ that do not decrease
with the radial quantum number $n$.
