μ\mu Parameter from Dynamical Rearrangement of U(1) and θ\theta Parameter

We study the generation of $\mu$ parameter from the dynamical rearrangement of local U(1) symmetry in a five-dimensional model and discuss phenomenological implications on the $\theta$ parameter, under the assumption that supersymmetry is broken by the Scherk-Schwarz mechanism.Comment: 16 page

Possibility of Direct Measurement of the Acceleration of the Universe Using 0.1 Hz Band Laser Interferometer Gravitational Wave Antenna in Space

It may be possible to construct a laser interferometer gravitational wave antenna in space with $h_{rms}\sim 10^{-27}$ at $f\sim 0.1{\rm Hz}$ in this century. We show possible specification of this antenna which we call DECIGO. Using this antenna we show that 1) typically $10^5$ ($10^4\sim 10^6$) chirp signals of coalescing binary neutron stars per year may be detected with S/N $\sim 10^4$. 2) We can directly measure the acceleration of the universe by ten years observation of binary neutron stars. 3) The stochastic gravitational waves of \Omega_{GW}\gsim 10^{-20} predicted by the inflation may be detected by correlation analysis for which effects of the recent cosmic acceleration would become highly important. Our formula for phase shift due to accelerating motion might be also applied for binary sources of LISA.Comment: 5 pages, 1 figure, revised version, Phys.Rev.Lett in pres

Family number, Wilson line phases and hidden supersymmetry

We study the relationship between the family number of chiral fermions and the Wilson line phases, based on the orbifold family unification. We find that flavor numbers are independent of the Wilson line phases relating extra-dimensional components of gauge bosons, as far as the standard model gauge symmetry is respected. This feature originates from a hidden quantum-mechanical supersymmetry.Comment: 17 pages, 1 figur

キイロショウジョウバエ由来のチオレドキシン還元酵素のC未端テトラペプチド配列は、ヒト肺由来のチオレドキシン還元酵素では酸化還元活性を示さない

The isozymes of mammalian thioredoxin reductase (TrxR) contain the penultimate selenocysteineresidue (SeCys) in the redox-active C-terminal tetrapeptide, -Gly-Cys-SeCys-Gly (end). Amutant form of the mammalian enzyme TrxR-X498C in which SeCys is replaced with Cys showsa dramatically decreased catalytic activity, suggesting that SeCys residue plays an integral role inthe catalysis. In contrast, TrxR of the fruit fly, Drosophila melanogaster, has no selenium in the corresponding C-terminal redox sequence, which instead of SeCys has flanking serine residues in the terminal sequence, -Ser-Cys-Cys-Ser (end). Because the catalytic activity of Dm-TrxR is comparable to that of the mammalian selenoenzyme, we introduced the serine residues at the corresponding positions of the recombinant TrxR-X498C and mimicked the redox center of the fruit fly TrxR. However, the catalysis remained as low as the Cys mutant of the selenoenzyme, suggesting that the additional structural features are still required for the tetrapeptide to function as a redox center. MOPAC calculation suggested that the complete motif might involve the hexapeptide sequence, which includes a proline residue, -Pro-X-Ser-Cys-Cys-Ser (end). The proline-containing motif is conserved among other insect TrxRs such as those of honeybee and fruit fly.ほ乳類チオレドキシン還元酵素はＣ末端配列-Gly-Cys-SeCys-Gly（end）の後ろから２番目にセレノシステイン（SeCys）残基を持つ．SeCys をシステインに変換すると酵素の活性は大きく低下するので，SeCys 残基が触媒活性に必須であることが分かる．これに対してキイロショウジョウバエのチオレドキシン還元酵素（Dm-TrxR）のＣ末端配列にはセレンが含まれず，システイン残基の対が２つのセリンに挟まれた配列-Ser-Cys-Cys-Ser (end）を持つ．それでも Dm-TrxR はほ乳類のセレン含有酵素と同程度の触媒能を示す．われわれはヒト肺チオレドキシン還元酵素に Dm-TrxR のＣ末端テトラペプチド配列を導入してその効果を調べた．しかし，酵素活性はまったく上昇せず，Dm-TrxR のＣ末端のテトラペプチド配列-Ser-Cys-Cys-Ser だけでは Cys 残基のチオール基を活性化する効果はなかった．そこで，分子軌道計算 MOPAC を用いて酸化還元機能を担うためのＣ末端配列モチーフを探索した．その結果，テトラペプチドにさらに２つ先のプロリンまでを含めた Pro-X-Ser-Cys-Cys-Ser（end）により初めて酸化還元モチーフとして機能する可能性が示唆された．Pro を含むこの配列モチーフはミツバチや蚊などほかの昆虫の TrxR でも保存されてい

Equivalence Classes of Boundary Conditions in SU(N) Gauge Theory on 2-dimensional Orbifolds

We study equivalence classes of boundary conditions in an SU(N) gauge theory on six-dimensional space-time including two-dimensional orbifold. For five kinds of two-dimensional orbifolds $S^1/Z_2 \times S^1/Z_2$ and $T^2/Z_m$ $(m=2,3,4,6)$, orbifold conditions and those gauge transformation properties are given and the equivalence relations among boundary conditions are derived. The classification of boundary conditions related to diagonal representatives is carried out using the equivalence relations.Comment: 18 pages, 4 figures, revised version for publication in PT

Soft Supersymmetry Breaking Masses and μ\mu Parameter from Dynamical Rearrangement of Exotic U(1) Symmetries

We propose a mechanism that the soft supersymmetry breaking masses and $\mu$ parameter can be induced from the dynamical rearrangement of local U(1) symmetries in a five-dimensional model. It offers to a solution of $\mu$ problem if there is a large hierarchy among the relevant U(1) charge of Higgsinos and that of hidden fields which stabilize the extra-dimensional component of U(1) gauge boson.Comment: 17 page

Orbifold family unification on six dimensions

We study the possibility of family unification on the basis of SU(N) gauge theory on the sixdimensional space-time, M-4 x T-2/Z(N). We obtain enormous numbers of models with three families of SU(5) matter multiplets and those with three families of the standard model multiplets, from a single massless Dirac fermion with a higher-dimensional representation of SU(N), through the orbifold breaking mechanism.ArticlePHYSICAL REVIEW D. 88(5):055016 (2013)journal articl

Effects of Cost and Benefit of Prosocial Behavior on Reputation

Prosocial behavior consists of a cost to the actor and a benefit of others. Previous studies have shown that prosocial actors generally receive positive social evaluations from observers. However, it is unknown how each component of prosocial behavior (i.e., cost and benefit) influences the two dimensions of person perception (i.e., warmth and competence). Thus, three studies investigated the independent effects of cost and benefit on the perceived warmth and competence of the actor. In Study 1, participants read a series of vignettes about a protagonist incurring a cost to benefit another individual and rated the warmth and competence of each protagonist. Although benefit enhanced both perceived warmth and competence, cost enhanced only perceived warmth. Studies 2a and 2b separately manipulated costs and benefits of prosocial behaviors in vignettes and confirmed the results of Study 1. Thus, this study demonstrated the independent effects of cost and benefit on person perception