Probing new physics in B -> f_0(980) K decays

Abstract

We study the hadronic decay modes $B^{\pm(0)} \to f_0(980) K^{\pm(0)} $, involving a scalar and a pseudoscalar meson in the final state. These decay modes are dominated by the loop induced $ b \to s \bar q q(q=s,u,d)$ penguins along with a small $ b \to u $ tree level transition (for $B^+ \to f_0 K^+$) and annihilation diagrams. Therefore, the standard model expectation of direct CP violation is negligibly small and the mixing induced CP violation parameter in the mode $B^0 \to f_0 K_S$ is expected to give the same value of $\sin(2\beta)$, as extracted from $B^0 \to J/\psi K_S$ but with opposite sign. Using the generalized factorization approach we find the direct CP violation in the decay mode $B^+ \to f_0 K^+ $ to be of the order of few percent. We then study the effect of the R-parity violating supersymmetric model and show that the direct CP violating asymmetry in $B^+ \to f_0(980) K^+ $ could be as large as $\sim 80 % $ and the mixing induced CP asymmetry in $B^0 \to f_0 K_S$ (i.e., $-S_{f_0 K_S}$) could deviate significantly from that of $\sin(2 \beta)_{J/\psi K_S}$.