https://doi.org/10.1140/epja/s10050-021-00428-5
Regular Article – Theoretical Physics
Semileptonic and nonleptonic decays of the axial-vector tetraquark 
1
Institute for Physical Problems, Baku State University, 1148, Baku, Azerbaijan
2
Department of Physics, University of Tehran, North Karegar Avenue, 14395-547, Tehran, Iran
3
Department of Physics, Doǧuş University, Acibadem-Kadiköy, 34722, Istanbul, Turkey
4
Department of Physics, Kocaeli University, 41380, Izmit, Turkey
Received:
14
October
2020
Accepted:
18
March
2021
Published online:
28
March
2021
The semileptonic and nonleptonic decays of the double-beauty axial-vector tetraquark to a state 
(hereafter 
and 
, respectively) are investigated in the context of the QCD sum rule method. The final-state tetraquark 
is treated as an axial-vector particle built of a heavy axial-vector diquark 
and light scalar antidiquark 
. Its spectroscopic parameters are calculated using the two-points sum rules by taking into account contributions of quark, gluon and mixed condensates up to dimension 10. We study the dominant semileptonic 
and nonleptonic decays 
, where M is one of the pseudoscalar mesons 
and 
. The partial widths of these processes are computed in terms of weak form factors 
, extracted by employing the QCD three-point sum rule approach. Predictions obtained for partial widths of considered decays are used to improve accuracy of theoretical predictions for full width and lifetime of the tetraquark , which are important for experimental exploration of this exotic meson.
© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2021
