Research On The Relativity Correction Of ?_b Radiation Decay To J/?

We research the relativistic correction to ?b radiative decays into J/? in the nonrelativistic QCD.Because two particles are heavy,both the bottomonium and the charmonium are non-relativistic bound states that are made up of heavy quark and heavy anti-quark.According to NRQCD factorization,for heavy quarks production and decay,decay width can be factorized into a short-distance part,which can be calculated in QCD perturbatively,and a long-distance part,which are governed by nonperturbative QCD dynamics.We can get the result for long-distance part by phenomenological model,lattice QCD and experimental data fitting.Among them,the short-range coefficient contains the contribution of the scale greater than or equal to M,and the contribution less than this scale is included in the non-perturbation long distance matrix element.The short-range coefficient is perturbation.And the long range although matrix elements is incalculable,but it has universality.In this paper,we calculate the radiative decays of the process ?b?J/? ?.The results are accurate to the decay widths of the leading relativistic correction.The process includes three parts:QED contributions,QCD contributions and the interference between them contributes.The coupling constants of QED are relatively small,which can decay through the tree diagram and has a fragmentation and elevation.So we include contributions from QED diagrams in the process.We will use the matching method in the factor theory to calculate the short coefficient of the leading order and the relativistic correction leading order matrix element,F1 and G1(G2).G1is the part of the short-distance coefficient of the relativistic correction for J/?,and G2 is the part of the short-distance coefficient of the relativistic correction for ?b.And we can select the appropriate non-perturbation matrix element.We can obtain the only prediction of the decay width.Although the decay width has no specific experimental result at present,Experiments can be measured to test the theory's predictive in the future.Because the calculation process is difficult,we use the computer software to generate Feynman diagram and then calculate the amplitude of Feynman diagram in the calculation process.We select the amplitude that meets the conservation of C parity by manually.And then we use FeynCalc to analyze high energy physics and use FIRE to reduce the Feynman amplitude and get MIs.In addition,the paper also uses OneLoop and PackagesX to integrate the part of the loop.At last,he Feynman amplitude can be calculated.We can also get the decay width.By matching method,we can calculate the short coefficient and select the appropriate non-perturbation matrix element.Finally,we get the decay width of the relativistic corrections to ?b radiative decays into J/?.The results show that the contribution of QED process was 16.7%,QCD contribution accounted for 71.7%,and the interference contribution between QED and QCD accounted for 9.9%when we don't consider relativistic correction.When we consider the relativistic correction of ?b,the decay of the QED process is depressed on the original basis.the contribution of QED process decreased,and the proportion of the interference contribution between QED and QCD increased.When we consider the relativistic correction of J/?,the contribution of the QCD process to the contribution of 61.2%to QED+QCD is 38.6%.