Rescattering information fromB→KK¯decays

Rescattering effects can modify the dependence on the weak phase $\gamma =-\mathrm{Arg}{(V}_{\mathrm{ub}}^{*}{V}_{\mathrm{ud}}{/V}_{\mathrm{cb}}^{*}{V}_{\mathrm{cd}})$ of the ratio of rates for $B^{\pm }\to K{\pi }^{\pm }$ and $\overrightarrow{B}{K}^{\pm }{\pi }^{\mp }.$ A test for these effects based on the processes $B^{\pm }\to K^{\pm }K$ has been suggested. It is pointed out that the rates for the processes $\overrightarrow{B}{K}^{+}{K}^{-},$ which are expected to be dominated by rescattering and for which considerably better experimental bounds exist, are likely to provide a more stringent constraint on these effects.