We study the pure penguin decays $\overrightarrow{B}\phi \pi$ and $B^0\to \phi \phi .$ Using QCD factorization, we find $\mathcal{B}{(B}^{\pm }\to \phi {\pi }^{\pm }{)=2.0\mathrm{}}_{-0.1}^{+0.3\mathrm{}}\times {10}^{-8}.$ For the pure penguin annihilation process $B^0\to \phi \phi ,$ analyzed here for the first time, $\mathcal{B}{(B}^0\to \phi \phi {)=2.1\mathrm{}}_{-0.3}^{+1.6\mathrm{}}\times {10}^{-9}.$ The smallness of these decays in the standard model makes them sensitive probes for new physics. From the upper limit of $\overrightarrow{B}\phi \pi ,$ we find constraints on R-parity violating couplings, $|{\lambda }_{i23\mathrm{}}^{″}{\lambda }_{i21\mathrm{}}^{″}|<6\mathrm{}\times {10}^{-5},$ $|{\lambda }_{i23\mathrm{}}^{\prime }{\lambda }_{i21\mathrm{}}^{\prime }|<4\mathrm{}\times {10}^{-4},$ and $|{\lambda }_{i32\mathrm{}}^{\prime }{\lambda }_{i12\mathrm{}}^{\prime }|<4\mathrm{}\times {10}^{-4}$ for $i=1,2,3.\mathrm{}$ Our new bounds on $|{\lambda }_{i23\mathrm{}}^{″}{\lambda }_{i21\mathrm{}}^{″}|$ are one order of magnitude stronger than before. Within the available upper bounds for $|{\lambda }_{i23\mathrm{}}^{″}{\lambda }_{i21\mathrm{}}^{″}|,$ $|{\lambda }_{i23\mathrm{}}^{\prime }{\lambda }_{i21\mathrm{}}^{\prime }|,$ and $|{\lambda }_{i32\mathrm{}}^{\prime }{\lambda }_{i12\mathrm{}}^{\prime }|,$ we find that $\mathcal{B}\left(\overrightarrow{B}\phi \phi \right)$ could be enhanced to ${10}^{-8}–{10}^{-7}.$ Experimental searches for these decays are strongly urged.

• Received 28 January 2002

DOI:https://doi.org/10.1103/PhysRevD.67.014007