We investigate the impact of extra vector-like GUT multiplets on the predicted value of the strong coupling. We find in particular that Yukawa couplings between such extra multiplets and the MSSM Higgs doublets can resolve the familiar two-loop discrepancy between the SUSY GUT prediction and the measured value of alpha_3. Our analysis highlights the advantages of the holomorphic scheme, where the perturbative running of gauge couplings is saturated at one loop and further corrections are conveniently described in terms of wavefunction renormalization factors. If the gauge couplings as well as the extra Yukawas are of O(1) at the unification scale, the relevant two-loop correction can be obtained analytically. However, the effect persists also in the weakly-coupled domain, where possible non-perturbative corrections at the GUT scale are under better control.
Yukawa Unification in Moduli-dominant SUSY Breaking
研究了模占优超对称破缺弦模型中的汤川统一。这种类型的超对称性断裂通常导致非通用的软物质，即，软标量质量和Gaugino质量。这种非普适性对于汤川统一的现象学方面很重要，即，成功的电弱破缺、对底部质量的超对称修正和$b \to s γ$的分支比。我们在整个参数空间中显示了三个区域，这导致成功的电弱破缺，并允许对底部质量进行小的超对称修正。对于这三个区域，我们研究了$b \to s γ$的衰变和质谱。
We propose a novel approach of probing grand unification through precise measurements on the Higgs Yukawa couplings at the LHC. This idea is well motivated by the appearance of effective operators not suppressed by the mass scale of unification $M_{\rm{U}}$ in realistic models of unification with the minimal structure of Yukawa sector. Such operators modify the Higgs Yukawa couplings in correlated patterns at scale $M_{\rm{U}}$ that hold up to higher-order corrections. The coherences reveal a feature that, the deviation of tau Yukawa coupling relative to its standard model value at the weak sc…
We discuss the Yukawa coupling unification, a very interesting prediction of the grand unified theory, in the context of scenarios with more than one pair of Higgs doublet since the current LHC constraint has become a problem for the Yukawa unification scenarios with just one pair of Higgs doublet. More than one pair of Higgs doublets can easily arise in missing partner mechanism which solves the doublet-triplet splitting problem. In such a scenario, the Yukawa unification occurs at a medium $\tanβ$ value, e.g., $\sim$ 30, which corresponds to much smaller threshold corrections compared to usu…
We investigate the Yukawa coupling unification for the third generation in a class of $\mathsf{SO(10)}$ unified models which are consistent with the 4.2 $σ$ deviation from the standard model of the muon $g-2$ seen by the Fermilab experiment E989. A recent analysis in supergravity grand unified models shows that such an effect can arise from supersymmetric loops correction. Using a neural network, we further analyze regions of the parameter space where Yukawa coupling unification consistent with the Fermilab result can appear. In the analysis we take into account the contributions to Yukawas fr…
We show that in the CMSSM with the non-holomorphic soft SUSY breaking terms, the Yukawa coupling unification of the third family fermions at the GUT scale, called $ t-b-τ$ Yukawa unification (YU), is possible under the recent collider and Dark Matter results. The YU parameter can also be found $ R_{tbτ} \approx 1 $, called perfect unification. We find that the squark masses exceed 3 TeV while the stau can be considerably lighter. In the case of YU, the $ \tanβ$ is in the interval $ [46,55] $. We obtain bino-like dark matter (DM) of mass in the range of $ 0.6$ TeV $ \lesssim m_{χ_{1}^{0}} \less…
t-b-tau Yukawa unification for mu < 0 with a sub-TeV sparticle spectrum
我们证明了在具有非普适Gaugino质量和MSSM参数μ < 0的超对称SU（4）_c x SU（2）_L x SU（2）_R中t-b-tau Yukawa耦合统一与所有已知实验约束的相容性。特别地，残余中性伴子丰度满足WMAP的界限，Delta（g-2）_mu与观测值符合得很好。我们确定的sparticle光谱，可以在LHC测试的基准点，包括与胶子和斯陶共湮没通道，混合bino-Higgsino状态和A-漏斗区域。我们还简要讨论了正在进行的和计划中的直接检测实验测试汤川统一的前景。
We investigate supersymmetric models with left-right symmetry based on the group $SU(4)_{c} \times SU(2)_{L} \times SU(2)_{R}$ ($4$-$2$-$2$) with negative sign of bilinear Higgs potential parameter $μ$ in the context of the latest experimental results. In the backdrop of experimental results from the Large Hadron Collider, we investigate the possibility of Yukawa unification in $4$-$2$-$2$ and find out the same is still not ruled out. Furthermore, this scenario also provides a satisfactory dark matter candidate. The current experimental bounds on sparticle masses, mass bounds on Higgs particle…
In the MSSM extended by a complete vectorlike family, precise top, bottom and tau Yukawa coupling unification can be achieved assuming SUSY threshold corrections which are typical for comparable superpartner masses. Furthermore, the unification is possible with a large unified coupling, implying that all three fermion masses can be simultaneously close to their IR fixed points. Assuming unified Yukawa couplings of order one or larger, the preferred common scale of new physics (superpartners and vectorlike matter) is in the 3 TeV to 30 TeV range, with larger couplings favoring smaller scales. S…
