Probing an axial-vector tetraquark $Z_s$ via its semileptonic decay $Z_s\to X(4274)\overline{l}\hat{I}{½}_l$

Abstract

The semileptonic decays of the open charm-bottom axial-vector tetraquark $Z_s=[cs][\overline{b}\overline{s}]$ to $X(4274)\overline{l}\hat{I}{½}_l$, $l=e,\hat{I}¼,\ddot{I}„$ are explored by means of the QCD three-point sum rule method. Both $Z_s$ and $X(4274)=[cs][\overline{c}\overline{s}]$ are treated as color sextet diquark-antidiquark states. The full width of the decays $Z_s\to X(4274)\overline{l}\hat{I}{½}_l$ is found. Obtained predictions for $\hat{I}“(Z_s\to X(4274)\overline{l}\hat{I}{½}_l)$ demonstrate that, as in the case of the conventional hadrons, the semileptonic transitions form a very small part of its full width.

8 Pages, 3 Figures and 1 Table