Search for Ionizing Tachyon Pairs From2.2−GeVc K−pInteractions

We have searched for pairs of charged particles $t^{+}{t}^{-}$ with spacelike four-momenta produced in $K^{-}p$ interactions at $2.2\frac{\mathrm{Gev}}{c}$. It was assumed that such particles could produce visible tracks in the bubble chamber. Under the additional assumption that only tachyons with velocities not much greater than the speed of light ($v\lesssim 1.7c$) could produce visible tracks, the experiment would be sensitive to tachyon invariant masses $\mu ={(-p·p)}^{\frac{1}{2}}$ between 100 MeV and 1 GeV and to tachyon-pair invariant-mass-squared values between 0 and 1.44 Ge${\mathrm{V}}^2$. No example of the reaction $K^{-}p\to \Lambda t^{+}{t}^{-}$ was found (for momentum transfer squared between 0 and -0.8 Ge${\mathrm{V}}^2$), implying a cross section upper limit of $\approx 0.2$ μb.