We show that chiral matters in the minimal supersymmetric standard model (MSSM) with semi-realistic flavor structures can be obtained from 7-brane configurations of magnetized super Yang-Mills (SYM) theory on a toroidal orbifold R1,3×(T2)3/(Z2×Z2′), where background magnetic fluxes and Wilson-lines are turned on preserving four-dimensional N=1 supersymmetry. The zero-mode spectrum of chiral multiplets in total is just MSSM ones, except the existence of those for three generations of right-handed neutrino and extra generations of MSSM Higgs pairs.Hierarchical Yukawa couplings can be obtained from the overlap integrals of wavefunctions localized in extra dimensions, allowing semi-realistic patterns of flavor structures for quarks and charged leptons. We also develop a systematic way to embed additional 7-branes into the configuration, those are sequestered from the visible sector toward a hidden sector model building.

We show that chiral matters in the minimal supersymmetric standard model (MSSM) with semi-realistic flavor structures can be obtained form 7-brane configurations of magnetized super Yang-Mills (SYM) theory on a toroidal orbifold R^1,3× (T^2)^3/(Z_2 × Z'_2), where background magnetic fluxes and Wilson-lines are turned on preserving four-dimensional N=1 supersymmetry. The zero-mode spectrum of chiral multiplets in total is just MSSM ones, except the existence of those for three generations of right-handed neutrino and extra generations of MSSM Higgs pairs. Hierarchical Yukawa couplings can be obtained from the overlap integrals of wavefunctions localized in extra dimensions, allowing semi-realistic patterns of flavor structures for quarks and charged leptons. We also develop a systematic way to embed additional 7-branes into the configuration, those are sequestered from the visible sector toward a hidden sector model building.

We compute the one-loop vacuum energy in 10-dimensional (10D) super Yang-Mills theory compactified on $\mathbb {R}<^>{1,3}\times (\mathbb {T}<^>2)<^>3$ in the presence of the Abelian magnetic fluxes. Regularization of the infinite Kaluza-Klein (KK) sum is achieved by the use of Barnes $\zeta$-functions, which can be applied to the case in which the KK mass spectrum has the Landau level structure. We apply the technique to two different models of the 10D super Yang-Mills theory: One is to introduce the magnetic flux background to the 10D super Yang-Mills action. The other is to first embed the 10D super Yang-Mills action into 4D $\mathcal {N}=1$ superspace and to introduce magnetic fluxes. The two models built result in different KK mass spectra as well as tree level potentials, and we compute the one-loop vacuum energy of each case. Nevertheless, both of the KK mass spectra have the Landau level structure and we can apply the regularization method in the same way. It turns out that the former model shows UV finite one-loop vacuum energy whereas the latter shows UV divergent one-loop potential that vanish when 4D ${\cal N}=1$ supersymmetry is not broken by magnetic fluxes. We discuss the origin of the differences from a higher-dimensional-supersymmetry viewpoint.

We discuss the behavior of the one-loop vacuum energy of 10 dimensional (10D) super Yang-Mills theory on magnetized tori ℝ^1,3× (𝕋^2)^3 in the presence of the Abelian magnetic fluxes, including all the contributions from Kaluza-Klein (KK) modes. Higher-dimensional super Yang-Mills action is known to be repackaged in terms of 4D 𝒩=1 superfield. We, however, find that such a superspace action differs from the original 10D super Yang-Mills action in the presence of magnetic fluxes. We show that the KK mass spectrum and hence the vacuum energy computed from these two actions differ from each other. In particular, we find that the UV divergence of the vacuum energy based on the original action precisely cancels independently of flux configuration whereas that based on the superspace completion does only when flux configuration preserves supersymmetry, which implies spontaneous or explicit breaking of hidden extended supersymmetry.

We discuss the effects of electric fields along compact directions within (supersymmetric) gauge theory in ℝ^1,3×T^2(×T^2×T^2) . The electric field along compact directions is equivalent to time-dependent homogeneous configuration of Wilson line moduli, which would be relevant to physics in the early universe. In particular, we consider models with and without background magnetic fluxes, which lead to completely different effects of the electric field due to the difference in the Kaluza-Klein (KK) level structure. We show that, in the case without magnetic fluxes, the deceleration of KK momenta may cause non-perturbative KK particle production dubbed as the KK Schwinger effect, whereas in the case with magnetic flux such KK particle production does not take place but flavor structure of low energy effective theory may be affected.

To investigate electronic states at the interface between surfaces that exhibit unique spin-split band dispersions is an important step in the development of a new materials that can be used to spintronics device. Antimony (Sb) and bismuth (Bi) are interesting targets for studying the nature of peculiar spin properties due to spin-orbit interactions. In this study, we fabricated the Sb ultrathin films on Bi substrate. The surface structure and electronic states of Sb/Bi heterostructure was confirmed by the low-energy electron diffraction measurement and angle-resolved photoemission spectroscopy, respectively. For 2 and 3 BL Sb film on Bi substrate, we observed a “V”-shaped electronic band, which is significantly different from the electronic state of Bi thin film and freestanding Sb ultrathin film. We conclude that this band dispersion is caused by the tensile lattice strain of Sb ultrathin film and the hybridization effect of the wavefunction with the Bi substrate.

The objective of this study was to develop a prediction equation for methane-related traits in beef cattle and evaluate this equation using datasets with different cattle breeds and roughage rates. Enteric methane emission (CH4 , l/day) was measured using open-circuit respiration chambers. Dry matter intake (DMI, kg/day), body weight (BW, kg), daily gain (DG, kg), total digestible nutrients (TDN, %DMI), and roughage rate (Rrate, %) were used as independent variables, and methane-related traits-CH4 , CH4 per DMI (CH4 /DMI, l/kg), and methane conversion factor (MCF, %)-were used as dependent variables. The best-fit equations to predict methane-related traits using a total of 76 records were CH4  = -676.7 + 0.04194 × BW + 29.88 × DMI + 7.883 × TDN + 4.367 × Rrate, CH4 /DMI = -52.24 - 1.193 × 10-3  × BW - 5.905 × DG + 1.077 × TDN + 0.5008 × Rrate, and MCF = -11.43 - 5.308 × 10-4  × BW - 1.223 × DG + 0.2336 × TDN + 0.1157 × Rrate. The predictive ability of the developed equations differed between roughage rates but not between breeds. For CH4 , the predictive ability of the developed equations was better compared with previously reported equations in the low roughage rate dataset, but not in the high roughage rate dataset. Our results suggest that the developed equations of methane-related traits can be applied in beef cattle fed with low roughage diets.

We study Fayet-Iliopoulos (FI) terms of six-dimensional supersymmetric Abelian gauge theory compactified on a T^2/Z_2 orbifold. Such orbifold compactifications can lead to localized FI-terms and instability of bulk zero modes. We study 1-loop correction to FI-terms in more general geometry than the previous works. We find induced FI-terms depend on the complex structure of the compact space. We also find the complex structure of the torus can be stabilized at a specific value corresponding to a self-consistent supersymmetric minimum of the potential by such 1-loop corrections, which is applicable to the modulus stabilization.

We pursue the time evolution of the domain walls in 5D gravitational theory with a compact extra dimension by numerical calculation. In order to avoid a kink-antikink pair that decays into the vacuum, we introduce a topological winding in the field space. In contrast to the case of non-gravitational theories, there is no static domain-wall solution in the setup. In the case that the minimal value of the potential is non-negative, we find that both the 3D space and the extra dimension will expand at late times if the initial value of the Hubble parameter is chosen as positive. The wall width almost remains constant during the evolution. In other cases, the extra dimension diverges and the 3D space shrinks to zero at a finite time.

We propose the Starobinsky-type inflationary model in the matter-coupled N = 1 four-dimensional supergravity with the massive vector multiplet that has inflaton (scalaron) and goldstino amongst its field components, whose action includes the Dirac-Born-Infeld-type kinetic term and the generalized (new) Fayet-Iliopoulos-type term, without gauging the R-symmetry. The N = 1 chiral matter ('hidden sector') is described by the modified Polonyi model needed for spontaneous supersymmetry breaking after inflation. We compute the bosonic action and the scalar potential of the model, and show that it can accommodate the positive (observed) cosmological constant (as the dark energy) and the spontaneous supersymmetry breaking at high scale after the Starobinsky inflation.

We study Fayet-Iliopoulos (FI) terms of 5-dimensional supersymmetric $U(1)$ gauge theory compactified on ${S}^{1}/{Z}_{2}$. In this model, loop diagrams including matter hypermultiplets and brane chiral multiplets induce FI-terms localized at the fixed points. Localized FI-terms lead instabilities of bulk modes. The form of the induced FI-terms strictly depends on wave function profiles of matter multiplets. It is a nontrivial question whether the vacuum of 1-loop corrected potential is stable under radiative corrections. We investigate this issue and it is found that the stable configuration is obtained when the bulk zero modes shield the brane charge completely.

We consider magnetized orbifolds, where the supersymmetric mass term for a pair of up- and down-type Higgs (super)fields, called μ-term, is localized at the orbifold fixed points, and study the effects on the zero-mode spectra. The zero-mode degeneracy to be identified as the generation in four-dimensional (4D) effective theories is determined by the magnetic fluxes. It is known that multiple Higgs zero-modes appear in general in magnetized orbifold models. We derive the analytic form of the μ-term matrix in the 4D effective theory generated by the localized sources on T2/Z2 orbifold fixed points, and find that this matrix can lead to a distinctive pattern of the eigenvalues that yields hierarchical μ-terms for the multiple Higgs fields. The lightest ones can be exponentially suppressed due to the localized wavefunctions of zero-modes determined by the fluxes, while the others are of the order of the compactification scale, which can provide a dynamical origin of the electroweak scale as well as a simultaneous decoupling of extra Higgs fields. We also show that a certain linear combination of the lightest Higgs fields could generate the observed mass ratios of down-type quarks through their Yukawa couplings determined by the wavefunctions.

We discuss an N=2 supergravity model that interpolates the full and the partial supersymmetry breakings. In particular, we find the conditions for an N=0 Minkowski vacuum, which is continuously connected to the partial-breaking (N=1 preserving) one. The model contains multiple (Abelian) vector multiplets and a single hypermultiplet, and is constructed by employing the embedding tensor technique. We compute the mass spectrum on the Minkowski vacuum, and find some non-trivial mass relations among the massive fields. Our model allows us to choose the two supersymmetry-breaking scales independently, and to discuss the cascade supersymmetry breaking for the applications to particle phenomenology and cosmology.

We study the supersymmetry breaking patterns in four-dimensional $$ \mathcal{N} $$ = 2 gauged supergravity. The model contains multiple (Abelian) vector multiplets and a single hypermultiplet which parametrizes SO(4, 1)/SO(4) coset. We derive the expressions of two gravitino masses under general gaugings and prepotential based on the embedding tensor formalism, and discuss their behaviors in some concrete models. Then we confirm that in a single vector multiplet case, the partial breaking always occurs when the third derivative of the prepotential exists at the vacuum, which is consistent with the result of ref. [1], but we can have several breaking patterns otherwise. The discussion is also generalized to the case of multiple vector multiplets, and we found that the full ( $$ \mathcal{N} $$ = 0) breaking occurs even if the third derivative of the prepotential is nontrivial.

We propose a four-dimensional N = 1 supergravity-based Starobinsky-type inflationary model in terms of a single massive vector multiplet, whose action includes the Dirac-Born-Infeld-type kinetic terms and a generalized (new) Fayet-Iliopoulos-type term, without gauging the R-symmetry. The bosonic action and the scalar potential are computed. The inflaton is the superpartner of the Goldstino in our model, and supersymmetry is spontaneously broken after inflation by the D-type mechanism, whose scale is related to the value of the cosmological constant.

We study magnetized orbifold models. We assume the localized Fayet-Iliopoulos terms and the corresponding gauge background. Such terms lead to strong localization of zero-mode wavefunc- tions. In this setup, we compute quark mass matrices.

We provide \( \mathcal{N}=1 \) superfield description of BPS backgrounds in six-dimensional supergravity (6D SUGRA) with 3-branes, which is compactified on a two-dimensional space. The brane terms induce the localized fluxes. We find a useful gauge in which the background equations become significantly simple. This is not the Wess-Zumino gauge, and the relation to the usual component-field expression of 6D SUGRA is not straightforward. One of the equations reduces to the Liouville equation. By moving to the Wess-Zumino gauge, we check that our expressions reproduce the known results of the previous works, which are expressed in the component fields. Our results help us develop the systematic derivation of four-dimensional effective theories that keeps the \( \mathcal{N}=1 \) SUSY structure.

We complete the four-dimensional \( \mathcal{N}=1 \) superfield description of six-dimensional supergravity. The missing ingredients in the previous works are the superfields that contain the sechsbein \( {e}_4^{\underline{\nu}},{e}_5^{\underline{\nu}},{e}_{\mu}^{\underline{4}},{e}_{\mu}^{\underline{5}} \) and the second gravitino. They are necessary to make the action invariant under the diffeomorphisms and the Lorentz transformations involving the extra dimensions. We find the corresponding superfield transformation laws, and show the invariance of the action under them. We also check that the resultant action reproduces the known superfield description of five-dimensional supergravity through the dimensional reduction.

We study Kahler moduli stabilizations in semirealistic magnetized D-brane models based on Z(2) x Z'(2) toroidal orbifolds. In type IIB compactifications, 3-form fluxes can stabilize the dilaton and complex structure moduli fields, but there remain some massless closed string moduli fields, Kahler moduli. The magnetic fluxes generate Fayet-Iliopoulos terms, which can fix ratios of Kahler moduli. On top of that, we consider D-brane instanton effects to stabilize them in concrete D-brane models and investigate the brane configurations to confirm that the moduli fields can be stabilized successfully. In this paper, we treat two types of D-brane models. One is based on D9-brane systems respecting the Pati-Salam model. The other is realized in a D7-brane system breaking the Pati-Salam gauge group. We find suitable configurations where the D-brane instantons can stabilize the moduli fields within both types of D-brane models, explaining an origin of a small constant term of the superpotential, which is a key ingredient for successful moduli stabilizations.