Contributions Of Heavy Gauge Boson W' In The 221 Model To The Radiative Leptonic Decays Of Heavy Mesons

The radiative leptonic decays of heavy mesons are very important in particle physics phenomenology.On one hand,these decays are used to detect the dynamics of strong interaction in the heavy mesons or study the effect of strong interaction in the decays.On the other hand,the radiative leptonic decays of heavy mesons provide a way of probing possible new physics effects related to the charged current interactions.At present,these decay modes have been investigated using the factorization approach and calculated up to the order O(?s ?QCD/mQ)in the standard model.In addition,the 221 model is one of the most popular new physics models.The most important feature of 221 model is the existence of new heavy gauge bosons W' and Z',which are relevant to the low energy charged and neutral current processes respectively.In the present work,we study the contributions of heavy gauge boson W' to the radiative leptonic decays of charged B and D mesons in the 221 model.Firstly,we give an introduction to the background and approaches related to our research,including the 221 model and the calculation of radiative leptonic decays of heavy mesons in the standard model.On this basis,considering the constraints on the model parameters from the latest experimental data,we calculate the contributions of heavy gauge boson W' in the 221 model to the radiative leptonic decays of charged B and D mesons.According to the patterns of gauge symmetry breaking,the 221 models can be divided into two classes.Due to the fact that the W' in the models of class? does not couple with the ordinary left-handed neutrinos and make no contributions to the radiative leptonic decays of charged B and D mesons,we only consider the contributions from W' in the models of class?,i.e.the non-universal and un-unified 221 models here.It is found that the corrections of W' in non-universal 221 model to the branching ratios of B-???-v? and B???-v? can be as large as 8%of the standard model values in the up-quark mixing scenario,which may be tested by more precise experiments such as LHCb,Belle? etc.in the future.In contrast,the corrections of W' in the un-unified 221 model to the radiative of leptonic decays of charged B and D mesons are negative and very tiny,around 0.3%of the corresponding standard model values.