A Determination of the Weak Phase \gamma from Color-allowed B^{\pm}_u   \to DK^{\pm} Decays
  We show that it is possible to determine the weak phase \gamma \equiv \arg (- V^*_{ub} V_{ud} / V^*_{cb} V_{cd}) of the Cabibbo-Kobayashi-Maskawa flavor mixing matrix only from the measurement of the color-allowed B^{\pm}_u \to D K^{\pm} decay rates. The uncertainty of this method, arising mainly from the factorization approximation for two tree-level spectator quark transitions, may be well controlled. 
Zhi-zhong Xing