Analysis of the Decay Mode D0 --> K- mu+ nu
by P.L. Frabetti et al.
Abstract: Studies of the decay $D^0\rightarrow {K}^{-}\mu^+\nu_{\mu}$ are reported by Fermilab photoproduction experiment E687. The ratio $BR(D^0\rightarrow {K}^{-}\mu^+\nu_{\mu})/ BR(D^0\rightarrow K^-\pi^+)$ is determined to be $0.852 \pm 0.034{\rm\ (statistical)} \pm 0.028{\rm\ (systematic)}$. Using this result and an isospin argument we infer the ratio $BR(D^0\to K^{*-}\mu^+\nu_\mu) /BR(D^0\to K^-\mu^+\nu_\mu)=0.62 \pm0.07\pm0.09$~. The pole mass from the single pole form factor is measured to be $M_{pole}=1.87^{+0.11+0.07}_{-0.08-0.06}~GeV/c^2$. Using $M_{pole}$ and $BR(D^0\rightarrow {K}^{-}\mu^+\nu_{\mu})/ BR(D^0\rightarrow K^-\pi^+)$, we calculate ${\left | f_{+}(0)\right |}=0.71 \pm 0.03 \pm 0.03$. We also measure the ratio $f_-(0)/f_+(0)=-1.3^{+3.6}_{-3.4}\pm0.6$~.