Hidden and doubly heavy molecular states from interactions D(s)(∗)D¯s(∗)/B(s)(∗)B¯s(∗) and D(s)(∗)Ds(∗)/B(s)(∗)Bs(∗)

In this work, we perform a systematical investigation about the possible hidden and doubly heavy molecular states with open and hidden strangeness from interactions of D ( ∗ ) D ¯ s ( ∗ ) / B ( ∗ ) B ¯ s ( ∗ ) , D s ( ∗ ) D ¯ s ( ∗ ) / B s ( ∗ ) B ¯ s ( ∗ ) , D ( ∗ ) D s ( ∗ ) / B ( ∗ ) B s ( ∗ ) , and D s ( ∗ ) D s ( ∗ ) / B s ( ∗ ) B s ( ∗ ) in a quasipotential Bethe-Salpeter equation approach. The interactions of the systems considered are described within the one-boson-exchange model, which includes exchanges of light mesons and J / ψ / Υ meson. Possible molecular states are searched for as poles of scattering amplitudes of the interactions considered. The results suggest that recently observed Z cs ( 3985 ) can be assigned as a molecular state of D ∗ D ¯ s + D D ¯ s ∗ , which is a partner of Z c ( 3900 ) state as a D D ¯ ∗ molecular state. The calculation also favors the existence of hidden heavy states D s D ¯ s / B s B ¯ s with spin parity J P = 0 + , D s D ¯ s ∗ / B s B ¯ s ∗ with 1 + , and D s ∗ D ¯ s ∗ / B s ∗ B ¯ s ∗ with 0 + , 1 + , and 2 + . In the doubly heavy sector, the bound states can be found from the interactions ( D ∗ D s + D D s ∗ ) / ( B ∗ B s + B B s ∗ ) with 1 + , D s D ¯ s ∗ / B s B ¯ s ∗ with 1 + , D ∗ D s ∗ / B ∗ B s ∗ with 1 + and 2 + , and D s ∗ D s ∗ / B s ∗ B s ∗ with 1 + and 2 + . Some other interactions are also found attractive, but may be not strong enough to produce a bound state. The results in this work are helpful for understanding the Z cs ( 3985 ) , and future experimental search for the new molecular states.