We derive the scalar resonance coupling constants of resonance chiral theory from the Extended Nambu Jona-Lasinio model by using heat-kernel expansion.
We show how the effective action of the Extended Nambu--Jona-Lasinio model (ENJL) can be defined in the presence of anomalies in a way that reproduces the flavour anomaly. This necessarily breaks Vector Meson Dominance (VMD) in the usual sense. The same method can be used to construct other chiral effective theories involving constituent quarks and spin-1 mesons that give the correct flavour anomaly. We also comment on how standard VMD is the root of this problem and those observed by previous authors in implementing VMD in the anomalous sector.
Effective quark model with chiral U(3)XU(3) symmetry for baryon octet and decuplet
我们提出了一个有效的夸克模型,它适用于由QCD激发的具有线性上升禁闭势的低位重子八重态和十重态,并结合了手征U(3)XU(3)对称性线性实现的扩展Nambu-Jona-Lasinio(ENJL)模型。重子被认为是外部重态,通过ENJL-模型中定义的夸克-介子相互作用与具有固定旋量结构的局部三夸克流耦合并与低位介子耦合。在组分夸克圈表象中,我们计算了(pi NN),(pi N Delta)和(gamma N Delta)相互作用的耦合常数以及(sigma_{πN})项。所得结果与实验数据和其它有效场论方法相符合。
We present an overview of the status and recent developments of FeynHiggs (current version: 2.14.3) since version 2.12.2. The main purpose of FeynHiggs is the calculation of the Higgs-boson masses and other physical observables in the MSSM. For a precise prediction of the Higgs-boson masses for low and high SUSY scales, state-of-the-art fixed-order and effective-field-theory calculations are combined. We first discuss improvements of the fixed-order calculation, namely an optional $\overline{\text{DR}}$ renormalization of the stop sector and a renormalization of the Higgs sector ensuring the c…
We present a complete set of decay rates of the Higgs boson with the mass of 125 GeV at the full next-to-leading order in a variety of extended Higgs models; i.e., a model with an additional real singlet scalar field, four types of two Higgs doublet models and the inert doublet model. All the one-loop contributions due to QCD and electroweak interactions as well as scalar interactions are taken into account, and the calculations are systematically performed. Branching ratios for all the decay modes are evaluated in these models, and patterns of deviations in each decay mode from the standard m…
Different approaches are used for the calculation of the SM-like Higgs boson mass in the MSSM: the fixed-order diagrammatic approach is accurate for low SUSY scales; the EFT approach,for high SUSY scales. Hybrid approaches, combining fixed-order and EFT calculations, allow to obtain a precise prediction also for intermediary SUSY scales. Here, we briefly discuss the hybrid approach implemented into the code FeynHiggs. In addition, we show how the refined Higgs mass prediction was used to define new MSSM Higgs benchmark scenarios.
Large Two-loop Effects in the Higgs Sector as New Physics Probes
我们考虑一个简单的希格斯门模型在超越标准模型的情况下:一个额外的真实规范单重标量耦合到希格斯。我们计算了Higgsstrahlung过程$e^+e^- \rightarrow Z h$截面的高回线修正,以及三-Higgs耦合和波函数重整化。我们发现,显着的贡献,总的Higgsstrahlung截面,特别是来自双回路图。我们还发现,当这个额外的标量是轻于质心能量的一半时,三希格斯耦合的校正是复杂的。它表示CP破坏的新来源。在该区域的额外标量轻于几百个GeV,我们认为,更高的循环计算是一个更可靠的方法比有效场论计算。
Testing nonperturbative techniques in the scalar sector of the standard model
我们讨论了强耦合下标准模型的标量扇区的当前图像。我们比较模式中观察到的标量部门在微扰理论中的两个循环与非微扰的解决方案,通过下一个领先的1/N扩展。特别地,我们分析了两个共振Higgs散射过程,ff -> H -> f 'f'和ff -> H -> ZZ,WW。我们描述的成分的非微扰计算,如快子正则化,高阶1/N中间重整化,和数值方法评估的图形。我们简要地讨论了这些非微扰方法扩展到其他理论的角度和实用性。
Penguin diagrams in the charm sector in K+ --> pi+ nu anti-nu
我们在次-主导阶(NNLO)下计算了QCD对企鹅图对衰变K+ --> pi+ nu anti-nu的魅力贡献的修正。文献中已有NNLO计算。我们提供了一个独立的检查结果的非异常和异常的图表。我们利用重整化群的改进和一个有效的理论框架对出现的大规模问题进行了归算。在非反常图的情况下,我们对退耦系数和反常维数的计算结果以及最后的数值计算结果与以前的计算结果一致。在异常的情况下,观察到的分析和数值的分歧。