Weak PhaseγUsing Isospin Analysis and Time-Dependent Asymmetry inBd→KSπ+π−

We present a method for measuring the weak phase $\gamma$ using isospin analysis of three body $B$ decays into $K\pi \pi$ channels. Differential decay widths and time-dependent asymmetry in $B_d\to K_S{\pi }^{+}{\pi }^{-}$ mode needs to be measured into even isospin $\pi \pi$ states. The method can be used to extract $\gamma$, as well as the size of the electroweak penguin contributions. The technique is free from assumptions like SU(3) or neglect of any contributions to the decay amplitudes. By studying different regions of the Dalitz plot, it may be possible to reduce the ambiguity in the value of $\gamma$.