https://doi.org/10.1140/epjp/s13360-023-03779-8
Regular Article
Form factors and branching fraction calculations for 
in view of LHCb observation
1
Department of Physics, Faculty of Science, The Maharaja Sayajirao University of Baroda, 390002, Vadodara, Gujarat, India
2
Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, 141980, Dubna, Russia
3
The Institute of Nuclear Physics, Ministry of Energy of the Republic of Kazakhstan, 050032, Almaty, Kazakhstan
4
Al-Farabi Kazakh National University, 050040, Almaty, Kazakhstan
5
Applied Physics Department, Faculty of Technology and Engineering, The Maharaja Sayajirao University of Baroda, 390001, Vadodara, Gujarat, India
6
Department of Physics, Sardar Patel University, 388120, Vallabh Vidyanagar, India
Received:
15
September
2022
Accepted:
7
February
2023
Published online:
18
February
2023
In light of the LHCb observations about the 
semileptonic decays, we study these channels within the standard model framework of covariant confined quark model. The necessary transition form factors are computed in the entire dynamical range of momentum transfer squared with built-in infrared confinement. Our computed ratios of the decay widths from tau mode to muon mode for 
and 
mesons are found to be 
and 
. We further determine the ratio of the decay width from and channel for muon mode 
. Our results are in excellent agreement with the data from the latest LHCb experiments as well as lattice quantum chromodynamics simulations. We also compare the shape of differential decay distribution for 
with the LHCb data, and our results are in very good agreement throughout all the individual bins. Some other physical observables such as forward-backward asymmetry and longitudinal polarizations of leptons in the final state are also computed.
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