Extraction method of $γ$ from semi-inclusive b ---> D s decays

Abstract

We propose a new method to extract a CP angle $γ$ from semi-inclusive two-body nonleptonic decays, b ---> D^0(\bar{D}^0) s and b ---> D_{CP} s. This method is free from the unknown long distance strong interaction effects and gives theoretically cleaner signal than the similar method using exclusive nonleptonic decays, B ---> D K. We can determine $γ$ with 4-$σ$ accuracy for 40^o < γ< 160^o.