On the production of the six-quarkHdibaryon in the (K−, K+) reaction

We investigate several ways of producing the stable doubly strange six-quark dibaryon $H$ predicted by the MIT bag model. Various kinematical and dynamical arguments indicate that the ($K^{-}, K^{+}$) double-strangeness-exchange reaction on nuclear targets affords the best chance for observing the $H$. Cross sections for the prototype reaction ${}_{}{}^3{}_{}{}^{}\mathrm{He}(K^{-}, K^{+}n)H$ are calculated, using empirical data on the reaction $K^{-}p\to K^{+}{\Xi }^{-}$ as input, as well as an oscillator model for the quark-fusion process ${\Xi }^{-}p\to H$. The spectrum for the quasielastic process ${}_{}{}^3{}_{}{}^{}\mathrm{He}(K^{-}, K^{+})n{\Xi }^{-}p$ is also calculated. For coincidence experiments involving both $K^{+}$ and neutron detection at forward angles, the cross section for $H$ production ranges from 10-30 nb/${\mathrm{sr}}^2$ for $K^{-}$ beam momenta between 1.4 and 2.2 GeV/c. If the $H$ lies below the $\Lambda \Lambda$ threshold, it can be nicely separated from the $K^{+}$ quasielastic background, although ${\pi }^{+}\text{'}\mathrm{s}$ misidentified as $K^{+}\text{'}\mathrm{s}$ can be a problem for certain $H$ masses. If only the $K^{+}$ is detected, the separation of the $H$ signal (≈ 0.5 μb/sr) from the quasielastic background can be achieved through a careful measurement of the $K^{+}$ momentum spectrum. We assess the effects on our results of the rapid momentum dependence in the $K^{-}p\to K^{+}{\Xi }^{-}$ reaction, as well as short-range correlations in the ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ wave function.