Using the Wetterich equation we study the renormalization group flow of a Higgs-Yukawa model, enjoying a chiral Z2 symmetry and with fermions being coupled to a SU(N) gauge field. Applying a systematic derivative expansion to the effective action and introducing a finite cut-off we are able to test a wide range of UV set ups while keeping the IR properties of the model fixed by means of experimental data such as top mass and the Higgs vacuum expectation value. The IR value of the Higgs mass however is understood as a function of the chosen UV set up and the cut-off. As a result, lower Higgs mass bounds arise in a natural way by the renormalization group flow itself, without making further assumptions on the (in)stability of the effective potential. We showed that by considering non-quartic UV potentials and higher-dimensional Yukawa operators, IR Higgs masses below the conventional bound can be generated.
We study the model which generates particle number asymmetry in the expanding universe. We derive the formula for the asymmetryin the universe of arbitrary time dependent scale factor. We first study it with perturbation around the flat universe and alsofor a specific case of radiation dominant universe.
可能な限り特定の模型に依存しないように拡張した有効ラグランジアンを用いて，t-> b W 崩壊過程に関連する理論値と実験値との比較から，トップ－ボトムーWボソン(tbW)相互作用の拡張制限を与えた.参考文献Z.~Hioki, K.~Ohkuma and A.~Uejima,Refined analysis and updated constraints on general non-standard tbW couplingsPhys. Lett. B 761 (2016) 219 [arXiv:1608.04057 [hep-ph]].
Among various dualities in string theory, T-duality is a symmetry, that relates different string backgrounds. Double field theory is a T-duality manifest formulation of the closed string sector. We provide a formulation of T-duality in toroidally compactified double field theory using the supergeometric method. Using this formulation we unify the description of (non-)geometric fluxes and deduce their Bianchi identities. Finally, the most general form of twisted Courant algebroids associated with various T-duality frames is constructed.
B to D^(*)^ l ν(l = e, μ,τ)において、素粒子標準模型の予言値と統計的に4σ程度のズレがあることが報告されている。標準模型にはないフレーバーの破れを持つ一般的なtwo Higgs doublet model (2HDM)を考え、そのズレを説明できるパラメータ領域を示す。さらに、2HDMではμτのフレーバーの破れがあればミュー粒子異常磁気能率のアノマリーを説明できることが知られているが、このシナリオでこのBの崩壊のズレも同時に説明できるかを議論する。
We study the Argyres-Douglas(AD) theories via ODE/IM correspondence. We take the light-cone limit of the modified affine Toda field equations and study the associated linear problems. From the top component of the solution of the linear problems, we derive the ordinary differential equations (ODE) which can be considered as the quantum Seiberg-Witten curve of Argyres-Douglas theories. Furthermore, the associated ``Bethe ansatz equations’’, ``central charges’’ and ``T-/Y-system’’ are derived from the ODEs. We compare the results with the known results in the AD theory obtained by using 2d/4d correspondence.
Spatially inhomogeneous magnetic fields superimposed with parallel dynamically assisting electric fields, which are known to improve the Schwinger mechanism, are investigated using the worldline formalism. Due to a quadratic reduction in the fermion mass from the inhomogeneity of the magnetic field, it is found that the rate for Schwinger pair production, the chiral magnetic effect (attributed to pair production chirality generation), and the dynamical fermion mass, resulting from a vacuum reorganization, and hence magnetic catalysis are enhanced.
We consider the condensation of extended topological defects associated with translational symmetry breaking: dislocation worldsheets. The Nambu-Goldstone bosons of the solid (phonons) are represented by Kalb-Ramond gauge fields that obtain a Higgs mass in the condensed phase, while Nambu-Goldstone bosons associated with remnant broken rotational symmetry deconfine as massless degrees of freedom. While rooted in condensed matter physics, this quantum phase transition sheds light on the Higgs mechanism of Kalb-Ramond fields, and also provides a complementary view of linearized gravity as the low-energy theory of a 4D liquid crystal.
In this paper, we revisit the gravitino dark matter scenario in the presence of the bilinear R- parity violating interaction. In particular, we discuss a consistency with the thermal leptogenesis. For a high reheating temperature required for the thermal leptogenesis, the gravitino dark matter tends to be overproduced, which puts a severe upper limit on the gluino mass. As we will show, a large portion of parameter space of the gravitino dark matter scenario has been excluded by combining the constraints from the gravitino abundance and the null results of the searches for the superparticles at the LHC experiments. In particular, the models with the stau (and other charged slepton) NLSP has been almost excluded by the searches for the long-lived charged particles at the LHC unless the required reheating temperature is somewhat lowered by assuming, for example, a degenerated right-handed neutrino mass spectrum.