X-0(2900) and its heavy quark spin partners in molecular picture

The X-0(2900), recently observed by the LHCb Collaboration in the D-K+ invariant mass of the B+ -> D+D-K+ process, is the first exotic candidate with four different flavors, beginning a new era for the hadron community. Under the assumption that the X-0(2900) is a I(J(P)) = 0(0(+)) (D) over bar *K* hadronic molecule, we extracted the whole heavy-quark symmetry multiplet formed by ((D) over bar, (D) over bar*) the doublet and the K* meson. For the bound state case, there would be two additional I(J(P)) = 0(1(+)) hadronic molecules associated with the (D) over barK* and (D) over bar *K* channels, as well as one additional I(J(P)) = 0(2(+)) (D) over bar *K* molecule. In the light quark limit, they are and below the and thresholds, respectively, which are unambiguously fixed by the mass position of the. For the virtual state case, there would be one additional I(J(P)) = 0(1(+)) hadronic molecule, strongly coupled to the (D) over barK* channel, and one additional I(J(P)) = 0(2(+)) (D) over barK* molecule. Searching for these heavy quark spin partners will help shed light on the nature of the X-0(2900).

Automated summary

The recently observed X-0(2900) is a unique candidate with four different flavors, possibly forming a (D)bar *K* hadronic molecule. The search for its heavy quark spin partners can help reveal the nature of X-0(2900) and provide insights into its various possible forms.