研究重味介子的两体非轻衰变有助于更深刻地理解量子色动力学(QCD)。理论上，相较轻子衰变及半轻衰变而言，由于涉及到定域算符使得对非轻衰变问题的处理变得困难。实验方面，对B、D介子许多两体非轻衰变道的分支比进行了测量，可为理论研究提供参考。
       本文在因子化假设的框架下，共计算了100个重味介子两体非轻衰变道的分支比，其中包括D介子的44个衰变道以及B介子的56个衰变道。因子化假设将衰变振幅写为衰变常数与形状因子乘积的形式。形状因子中蕴含着动力学信息且影响分支比的计算结果，是十分重要的输入量。本文选择基于相对论夸克模型计算的形状因子。第一章为引言，简要介绍了研究背景及研究方法。第二章介绍了在协变光前夸克模型及相对论夸克模型下计算形状因子的方法，并给出选择后者进行数值计算的原因。在第三章中，给出重味介子两体非轻衰变振幅的详细推导，并将数值结果与实验测量值及其他理论计算值进行了比较。对于D介子，我们再次验证了将夸克颜色数N取作∞会大幅提高理论计算值与实验值的吻合程度。对于B介子，我们额外考虑了企鹅算符的贡献，它在某些衰变道中不可忽略甚至占主导地位，如B+→π+φ,π+K0,ρ+K0等。第四章为总结及展望。
       从结果上来看，大多数分支比的理论结果与实验值量级吻合，然而想要得到更精确的定量结果，必须对末态相互作用进行认真分析。

 Nonleptonic decays ofthe heavy mesons offer an important environment to understand the nature of quantum chromodynamics(QCD). The oretically nonleptonic decays involve more complex mechanism than the leptonic and semileptonic ones due to the local four-quark operators. The branching fractions of many two-body non-leptonic decay channels of B and D meson was measured,which can provide a reference for theoretical research.
     In the framework of the factorization approach, we calculate the branching fractions of 100 decay channels in total,including 44 channels of charm meson decays and 56 beauty meson decays.In the factorization approach, the hadronic matrix element can be expressed by the product of decay constant and the invariant form factors. The result of the branching fractions depends on the form factor which contains dynamic information. Thus form factor is an important input. The first 
 chapter is an introduction,which briefly introduces there search background and research methods. In the second chapter, we introduce two methods to calculate the form factor based on the covariant light-front quark model and relativistic quark model. And we also give the reason why we choose the latter for a numerical calculation. In the third chapter, we give the derivation of two-body nonleptonic decay amplitude of the heavy flavor meson, and compare the numerical results with experimental measurements and othert heoretical predictions. For charm meson decay, we test and verify again that taking the number of color N→∞ improves a lot the theoretical predictions. For beauty meson decay, we additionally consider the contribution of the penguin operator, which can not be ignored or even dominant in some decay channels, such as B+→π+φ,π+K0,ρ+K0. The final chapter is a summary and outlook.
   In general, the predictions for the branching fractions are acceptable in the order of the magnitude. However, for a quantitative calculation, more subtlety of final-state interaction effectis necessarily to be determined.