We present new CDF results on the branching fractions and time-integrated direct CP asymmetries for $B^{ 0}$ and $B^{ 0}_{ s}$ decay modes into pairs of charmless charged hadrons (pion or kaon). The data set for this update amounts to 1 fb$^{ -1}$ of $\bar{ p}p$ collisions at $\sqrt{ s}=1.96 \rm{ TeV}$. We report the first observation of the $B^{ 0}_{ s} \to K^{ -}\pi^{ +}$ mode and a measurement of its branching fraction and direct CP asymmetry. We also observe for the first time two charmless decays of $b$-baryon: $\Lambda^{ 0}_{ b} \to p\pi^{ -}$ and $\Lambda^{ 0}_{ b} \to pK^{ -}$.
Categories: hep-ex