On integrable natural Hamiltonian systems on the suspensions of toric automorphism

We point out a mistake in the main statement of \cite{liu} and suggest and proof a correct statement.Comment: 5 pages, no figure

Precision Measurements of the Semileptonic Charm Decays D0→π−ℓ+νD^0 \to \pi^- \ell^+ \nu and D0→K−ℓ+νD^0 \to K^- \ell^+ \nu

We investigate the decays $D^0\to\pi^-\ell^+\nu$ and $D^0\to K^-\ell^+ \nu$, where $\ell$ is $e$ or $\mu$, using approximately 7 ${\rm fb}^{-1}$ of data collected with the CLEO III detector. We find $R_0\equiv {\cal B}(D^0\to \pi^-e^+\nu)/{\cal B}(D^0\to K^-e^+\nu)= 0.082 \pm 0.006 \pm 0.005$. Fits to the kinematic distributions of the data provide parameters describing the form factor of each mode. Combining the form factor results and $R_0$ gives $|f^{\pi}_{+}(0)|^2 |V_{cd}|^2/|f^K_{+}(0)|^2 |V_{cs}|^2 = 0.038^{+0.006+0.005}_{-0.007-0.003}$.Comment: 5 pages, 2 figures, talk given at DPF'04, UC Riverside, C