Possible signatures of unparticles in rare annihilation type $B$ decays

We investigate the effect of unparticles in the pure annihilation type decays $B^{-}\to D_s^{-}\varphi$ and $D_s^{-}{K}^{*0}$. Since these decays have only annihilation contributions their branching ratios are expected to be very small in the standard model and the direct $CP$ asymmetry parameters to be zero. We find that due to the unparticle effect these branching ratios can be significantly enhanced from their standard model values. Furthermore, sizable nonzero direct $CP$ violation could also be possible in these channels due to the presence of intrinsic $CP$ conserving phase in the unparticle propagator.

Figure 1

$CP$ averaged branching ratio $⟨\mathrm{Br}⟩$ (in units of ${10}^{-7}$) and $CP$ violation parameter (in %) for the decay mode $B^{-}\to D_s^{-}\varphi$, where the solid lines, dashed lines, and dot-dashed lines correspond to $\lambda =1$, 0.1, and 0.05, respectively. The horizontal thick line in the branching ratio plot represents the experimental upper limit.

Figure 2

$CP$ averaged branching ratio $⟨\mathrm{Br}⟩$ (in units of ${10}^{-8}$) and $CP$ violation parameter (in %) for the decay mode $B^{-}\to D_s^{-}{K}^{*0}$. The solid lines, dashed lines, and dot-dashed lines correspond to $\lambda =1$, 0.1, and 0.05, respectively.