论文标题
LSS Little-higgs中的紧急2HDM：来自风味和electroweak物理的沉思
Emergent 2HDM in LSS Little-Higgs: Musings from Flavor and Electroweak Physics
论文作者
论文摘要
Low，Skiba和Smith（LSS）提出的Little-Higgs模型的低能效率理论（$ \ sim $ tev）展示了两吉格斯Doublet模型（2HDM）结构。对称性决定了有趣的野川模式，将其与两个Higgs Doublets的非平凡费米耦合。标量与费米子的耦合可以引起风味变化的中性电流（FCNC），从风味物理学上获得限制，例如br $（b \ rightArrowx_sγ）$，$ b_s -\ b_s -\ bar {b} _s $混合等。大型强子对撞机（LHC）的耦合测量值也对LSS模型进行了严格的限制。超出标准模型（BSM）颗粒的直接LHC搜索结果也对质量施加了边界。我们通过多维参数空间中的随机扫描来探测上述约束的LSS模型。我们观察到，与一般的2HDM场景相反，LSS模型的紧急2HDM与风味数据和$ z b \ bar {b} $测量的限制较少，但在LHC处受到了electroweak（ew）搜索的严格限制。从风味数据和$ z b \ bar {b} $中，我们发现被带电的希格斯质量放松了，$ \tanβ$仅限于$ 0.5-5 $，而被带电的希格斯质量则将其推向超过1 tev，而$ \tanβ$又被限制在$ <3 $ $ <3 $时。
The low energy effective theory ($\sim$ TeV) of the little-Higgs model with $SU(6)/Sp(6)$, as proposed by Low, Skiba and Smith (LSS), exhibits a two-Higgs doublet model (2HDM) structure. The symmetry dictates interesting Yukawa patterns, translating to non-trivial fermion couplings with both of the Higgs doublets. The couplings of the scalars with the fermions can induce flavor changing neutral currents (FCNC), which get constraints from flavor physics observables such as BR$(B\rightarrow X_sγ)$, $B_s - \bar{B}_s$ mixing etc. The precision measurement of $Z b \bar{b}$ vertex, the top and Higgs mass along with other Higgs coupling measurements at the Large Hadron Collider (LHC) also enforce severe restrictions on the LSS model. Direct LHC search results of beyond the Standard Model (BSM) particles also impose bounds on the masses. We probe the LSS model in view of the above constraints through a random scan in the multi-dimensional parameter space. We observe, on contrary to the general 2HDM scenario, the emergent 2HDM from the LSS model is less constrained from the flavor data and the $Z b \bar{b}$ measurement but is severely constrained form the electroweak (EW) searches at the LHC. From the flavor data and $Z b \bar{b}$, we find that the charged Higgs mass is relaxed with $\tanβ$ being restricted to $0.5-5$, whereas the charged Higgs mass is pushed to larger than 1 TeV along with $\tanβ$ being further restricted to $< 3$ when the LHC bounds are incorporated.
