  Let $-D < -4$ denote a fundamental discriminant which is either odd or
divisible by 8, so that the canonical Hecke character of $\Bbb Q(\sqrt{-D})$
exists. Let $d$ be a fundamental discriminant prime to $D$. Let $2k-1$ be an
odd natural integer prime to the class number of $\Bbb Q(\sqrt{-D})$. Let
$\chi$ be the twist of the $(2k-1)$th power of a canonical Hecke character of
$\Bbb Q(\sqrt{-D})$ by the Kronecker's symbol $n\mapsto(\frac{d}{n})$. It is
proved that the order of the Hecke $L$-function $L(s,\chi)$ at its central
point $s=k$ is determined by its root number when $|d| \leq
c(\epsilon)D^{{1/24}-\epsilon}$ or, when $|d| \leq c(\epsilon)D^{\frac1{12}
-\epsilon}$ and $k\geq 2$, where $\epsilon > 0$ and $c(\epsilon)$ is a constant
depending only on $\epsilon$.
