Branching Fractions and Direct CP Asymmetries of Charmless B Decay Modes at CDF

Abstract

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 (pions or kaons). The data-set for this update amounts to 1 $\mathrm{fb}^{-1}$ of $p\bar p$ collisions at a center of mass energy 1.96 $\mathrm{TeV}$. We report the first observation of the $B_s \to K^- \pi^+$ mode and a measurement of its branching fraction and direct CP asymmetry. We also observe for the first time two charmless decays of the $\Lambda_b^0$-baryon: $\Lambda_b^0 \to p\pi^-$ and $\Lambda_b^0 \to pK^-$.