Universal extra dimensions and b→sγ
Universal extra dimensions and b→sγ
复制标题
通用额外维度和 b→sγ
DOI：
10.1016/s0370-2693(01)00791-2
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发表时间：
2001
影响因子：
4.4
通讯作者：
G. Wu
中科院分区：
文献类型：
--
作者：
K. Agashe;N. Deshpande;G. Wu
我们分析了平坦的普遍额外维度（即，所有SM域都可访问的额外维度）。对于一个希格斯双重态，单圈的主要贡献来自带电的戈德斯通玻色子（WGB）和顶夸克的卡鲁扎-克莱因（KK）态。由此产生的对额外标注大小的约束与T参数的约束相当。在双Higgs二重态模型II中，荷电Higgs粒子的零模和KK态的贡献可以抵消WGB KK态的贡献。因此，在这个模型中，从过程B→sγ得到的额外维度的大小没有约束，而且与4D相比，从这个过程得到的带电希格斯粒子的质量约束也被削弱了。在双Higgs二重态模型Ⅰ中，荷电Higgs粒子的零模和KK态的贡献与WGB粒子的KK态的贡献同号。因此，在这个模型中，并且对于小的tanβ，对额外维度的大小的约束比在一个希格斯偶极子模型中更强，并且对带电希格斯粒子的质量的约束也比在4D中更强。
We analyze the effect of flat universal extra dimensions (i.e., extra dimensions accessible to all SM fields) on the process b→sγ. With one Higgs doublet, the dominant contribution at one-loop is from Kaluza–Klein (KK) states of the charged would-be-Goldstone boson (WGB) and of the top quark. The resulting constraint on the size of the extra dimension is comparable to the constraint from T parameter. In two-Higgs-doublet model II, the contribution of zero-mode and KK states of physical charged Higgs can cancel the contribution from WGB KK states. Therefore, in this model, there is no constraint on the size of the extra dimensions from the process b→sγ and also the constraint on the mass of the charged Higgs from this process is weakened compared to 4D. In two-Higgs-doublet model I, the contribution of the zero-mode and KK states of physical charged Higgs and that of the KK states of WGB are of the same sign. Thus, in this model and for small tanβ, the constraint on the size of the extra dimensions is stronger than in one-Higgs-doublet model and also the constraint on the mass of the charged Higgs is stronger than in 4D.