用Technicolor理论研究稀有辐射衰变B_c→D_sγ

A Study on Rare Radiative Decay Bc→Dsγ in Technicolor Models

在一代Ｔｅｃｈｎｉｃｏｌｏｒ（ＴＣＩ）和带有一个无质量的标量二重态（ＴＣⅡ）模型下，计算荷电的哥尔斯通粒子对衰变Ｂ＿ｃ→Ｄ＿ｓγ的贡献，并把它们同标准模型的计算相比较，发现哥尔斯通粒子对电磁企鹅图的贡献很大（ＴＣＩ下），在ＴＣⅡ下贡献较小；而对弱湮没图的贡献可以忽略不计，还对同位旋三重态粒子π＋ｐ的质量进行了约束。预言将来在ＬＨＣ上能对不同模型下的分支比Ｂｒ（Ｂｃ→Ｄｓγ）的差异进行研究，进而对不同的模型进行检验。

We calulate the psedo-Goldstone-bosons (PGB)contributions to thedecay Bc →Ds γ in one generation technicolor model (TCI) and the technicolor model with massless doublet (TCⅡ),and compare with thecontributions estimated in the standard model. We find that thecontributions of PGBs in the TCⅠ tothe electri-magnetic penguin dirgram are large, whereas those of the TCⅡ are small. However, thecontributions to the weak annihilation diagrams can be neglected. Itis expected that the difference of the branching ratio Br (Bc→Dsγ)in various models can be studied at LHC in near future, and will be animportant test to different models.