Weak-decay searches for Qs(u)over-bar(d)over-bar tetraquarks

We propose to search for the open heavy-flavor exotic states with the quark components of Qs (u) over bar(d) over bar with Q = b, c via their weak decays. If there exist such exotic states below the BK or DK thresholds, they can only decay weakly. The advantages include: (i) the experimental backgrounds from the secondary decay vertex are much lower due to the long lifetimes, (ii) the productions are large enough for only one heavy quark in such states, (iii) the thresholds of BK or DK are about 260 MeV higher compared to the B-s pi or D-s pi thresholds of the configurations of Qu (s) over bar(d) over bar or Qd (s) over bar(u) over bar, with a higher possibility to exist such weakly-decay particles, and (iv) if observed, their inner structures are easier understood since they can not be induced by the kinematic effects.

Automated summary

This paper proposes to search for open heavy-flavor exotic states with certain quark components through their weak decays. If these states exist below a specific threshold, they can only undergo weak decays. The advantages of this approach include low experimental backgrounds, large production rates, and easier understanding of their inner structures.