Finding a clean process $B^- \to K^- D^0 K^0$ to probe absolutely exotic four-quark states

Abstract: Motivated by the observations of $T_{c\bar{s}0}(2900)^0$ and $T_{c\bar{s}0}(2900)^{++}$, we propose to search for $T_{c\bar{s}0}(2900)^0$ in the cleaner process $B^- \to K^- D^0 K^0$. In the $D^K^$ molecular picture, our estimates suggest that $T_{c\bar{s}0}(2900)^0$ should contribute significantly to the $D^0 K^0$ invariant mass distribution in $B^- \to K^- D^0 K^0$, as reported by the Belle II Collaboration. The corresponding fit fraction is estimated to be $(9.72\pm 3.92)\%$. Further precise measurements of this process at Belle II and LHCb could help clarify the nature of $T_{c\bar{s}0}(2900)$.