Hunting for the alpha: $B\to \rho\rho$, $B \to \pi\pi$, $B \to\pi\rho$
  The hypothesis of the smallness of penguin contribution to charmless strangeless $B_d (\bar B_d)$ decays allows to determine with high accuracy the value of angle $\alpha$ from the currently available $B \to \rho\rho$, $B \to \pi\pi$ and $B\to \rho\pi$ decay data. 
G.G.Ovanesyan, (Moscow Institute of Physics and Technologies and   ITEP), M.I.Vysotsky, (ITEP)