Isfahan University of Technology, The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 21 4 2022 02 20 The study of decay with the calculation of its branching ratio The study of decay with the calculation of its branching ratio 701 705 1756 10.47176/ijpr.21.4.21181 FA A Abdi Saray Department of Physics, Faculty of Science, Urmia University, Urmia, Iran 0000-0001-9797-1994 N Bakhshi Department of Physics, Faculty of Science, Urmia University, Urmia, Iran B Mohammadi Department of Physics, Faculty of Science, Urmia University, Urmia, Iran Journal Article 2020 12 28 In this paper, the decay of the  meson into two vector mesons  and  is investigated.The first observation of the decay was reported in 2017 by LHCb collaboration, they have obtained the value of B () = (5. 01 ± 053 ± 0.27 ± 0.06)×10<sup>-4</sup>. In this study, the Feynman diagram of  decay is drawn based on the standard model. In particular this diagram shows that the decay consists of tree-exchange internal w-emission graph and penguin- suppressed graph. The coefficients of a<sub>2</sub>, a<sub>3</sub>, a<sub>5</sub> and a<sub>7</sub> are calculated in the NLO scale. The branching ratio is calculated using the QCD factorization method, numerical values in the NLO (at m<sub>b</sub> scale) scheme is 5.33×10<sup>-4</sup>, for which are in good agreement with the experimental results. The more calculations accuracy increases, the b quark mass scales come down corresponding to that. The best answer close to the experimental value is in NLO scheme at m<sub>b</sub> scale of QCDF approach.‎ In this paper, the decay of the  meson into two vector mesons  and  is investigated.The first observation of the decay was reported in 2017 by LHCb collaboration, they have obtained the value of B () = (5. 01 ± 053 ± 0.27 ± 0.06)×10<sup>-4</sup>. In this study, the Feynman diagram of  decay is drawn based on the standard model. In particular this diagram shows that the decay consists of tree-exchange internal w-emission graph and penguin- suppressed graph. The coefficients of a<sub>2</sub>, a<sub>3</sub>, a<sub>5</sub> and a<sub>7</sub> are calculated in the NLO scale. The branching ratio is calculated using the QCD factorization method, numerical values in the NLO (at m<sub>b</sub> scale) scheme is 5.33×10<sup>-4</sup>, for which are in good agreement with the experimental results. The more calculations accuracy increases, the b quark mass scales come down corresponding to that. The best answer close to the experimental value is in NLO scheme at m<sub>b</sub> scale of QCDF approach.‎ B meson decay factorization method Feynman diagram form factor decay rate branching ratio https://ijpr.iut.ac.ir/article_1756_1fb91f3bf77f0bacc6c29c80df4b540a.pdf