First Evidence for B_s -> phi phi and Other Penguin B decays at CDF

TL;DR

This paper reports the first evidence for the decay B_s -> phi phi and measures related branching ratios and CP asymmetry using data from the CDFII experiment, advancing understanding of penguin B decays.

Contribution

It provides the first experimental evidence for B_s -> phi phi decay and measures its branching ratio and CP asymmetry, offering new data on charmless B decays.

Findings

First evidence for B_s -> phi phi decay

Measured branching ratio BR(B_s -> phi phi) = (1.4 ± 0.6(stat) ± 0.2(syst) ± 0.5(BR)) x 10^{-5}

Measured CP asymmetry ACP(phi K) = -0.07 ± 0.17 (stat) ± 0.06/0.05 (syst)

Abstract

We present the first evidence of the decay mode $B_s \to \phi \phi$ and a measurement of partial width and direct CP asymmetry for the $B^+ \to \phi K^+$ decay using $180 pb^{-1}$ of data collected by the CDFII experiment at the Fermilab Tevatron collider. We measure: $BR (\phiphi) = (1.4 \pm 0.6(stat.) \pm 0.2(syst.) \pm 0.5(\BR)) \cdot 10^{-5}$, where the last error is due to the uncertainty on the $B_s \to J/\psi\phi$ branching ratio used as normalization, $BR (\phi k) = (7.2 \pm 1.3(stat.) \pm 0.7(syst.)) \cdot 10^{-6}$ and $\ACP(phi k) = -0.07 \pm 0.17 (stat.) \ase{0.06}{0.05} (syst.)$. We also briefly discuss prospects for studying other charmless $B \to VV$ decays at CDF