Updated on 2022/05/17

写真a

 
ABE, Hiroyuki
 
Affiliation
Faculty of Science and Engineering, School of Advanced Science and Engineering
Job title
Professor

Concurrent Post

  • Faculty of Science and Engineering   Graduate School of Advanced Science and Engineering

Research Institute

  • 2020
    -
    2022

    理工学術院総合研究所   兼任研究員

Degree

  • Hiroshima University   Master of Science

  • Hiroshima University   Doctor of Science

Professional Memberships

  •  
     
     

    The Physical Society of Japan

 

Research Areas

  • Theoretical studies related to particle-, nuclear-, cosmic ray and astro-physics

Research Interests

  • Theoretical elementary particle physics

Papers

  • Behaviors of two supersymmetry breaking scales in N=2 supergravity

    Hiroyuki Abe, Shuntaro Aoki, Sosuke Imai, Yutaka Sakamura

    Journal of High Energy Physics   19 ( 11-101 ) 0 - 24  2019.11  [Refereed]

    DOI

  • Revisiting instabilities of S1/Z2 models with loop-induced Fayet-Iliopoulos terms

    Hiroyuki Abe, Tatsuo Kobayashi, Shohei Uemura, Junji Yamamoto

    Physical Review D   100 ( 6 ) 065020-1 - 065020-10  2019.09  [Refereed]

    DOI

  • Effects of localized mu-terms at the fixed points in magnetized orbifold models

    Hiroyuki Abe, Makoto Ishida, Yoshiyuki Tatsuta

    Nuclear Physics B   947   1 - 20  2019.08  [Refereed]

    DOI

  • Interpolation of partial and full supersymmetry breakings in N=2 supergravity

    Hiroyuki Abe, Shuntaro Aoki, Sosuke Imai, Yutaka Sakamura

    Nuclear Physics B   946 ( 114690 ) 1 - 27  2019.07  [Refereed]

    DOI

  • Polonyi–Starobinsky supergravity with inflaton in a massive vector multiplet with DBI and FI terms

    Hiroyuki Abe, Yermek Aldabergenov, Shuntaro Aoki, Sergei V. Ketov

    Classical and Quantum Gravity   36 ( 7 ) 075012-1 - 075012-24  2019.03  [Refereed]

    DOI

  • Quark mass matrices in magnetized orbifold models with localized Fayet-Iliopoulos terms

    Hiroyuki Abe, Tatsuo Kobayashi, Shintaro Takada, Shio Tamba, Takuya H. Tatsuishi

    Physical Review D   98 ( 106017 ) 106017-1 - 106017-8  2018.11  [Refereed]

    DOI

  • N=1 superfield description of BPS solutions in 6D gauged SUGRA with 3-branes

    Hiroyuki Abe, Shuntaro Aoki, Sosuke Imai, Yutaka Sakamura

    Journal of High Energy Physics   18 ( 09-073 ) 0 - 28  2018.09  [Refereed]

    DOI

  • Massive vector multiplet with Dirac-Born-Infeld and new Fayet-Iliopoulos terms in supergravity

    Hiroyuki Abe, Yermek Aldabergenov, Shuntaro Aoki, Sergei V. Ketov

    Journal of High Energy Physics   18 ( 09-094 ) 0 - 21  2018.09  [Refereed]

    DOI

  • Full diffeomorphism and Lorentz invariance in 4D N=1 superfield description of 6D SUGRA

    Hiroyuki Abe, Shuntaro Aoki, Yutaka Sakamura

    JOURNAL OF HIGH ENERGY PHYSICS   17 ( 11 ) 0 - 37  2017.11  [Refereed]

     View Summary

    We complete the four-dimensional N = 1 superfield description of sixdimensional supergravity. The missing ingredients in the previous works are the superfields that contain the sechsbein e(4)((v) under bar), e(5)((v) under bar), e(mu)((4) under bar), e(mu)((5) under bar) 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.

    DOI

  • Kahler moduli stabilization in semirealistic magnetized orbifold models

    Hiroyuki Abe, Tatsuo Kobayashi, Keigo Sumita, Shohei Uemura

    PHYSICAL REVIEW D   96 ( 2 ) 026019-1 - 026019-11  2017.07  [Refereed]

     View Summary

    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.

    DOI

  • Supersymmetric models on magnetized orbifolds with flux-induced Fayet-Iliopoulos terms

    Hiroyuki Abe, Tatsuo Kobayashi, Keigo Sumita, Yoshiyuki Tatsuta

    PHYSICAL REVIEW D   95 ( 1 ) 15005-1 - 15005-14  2017.01  [Refereed]

     View Summary

    We study supersymmetric (SUSY) models derived from the ten-dimensional SUSY Yang-Mills theory compactified on magnetized orbifolds, with nonvanishing Fayet-Iliopoulos (FI) terms induced by magnetic fluxes in extra dimensions. Allowing the presence of FI- terms relaxes a constraint on flux configurations in SUSY model building based on magnetized backgrounds. In this case, charged fields develop their vacuum expectation values to cancel the FI- terms in the D-flat directions of fluxed gauge symmetries, which break the gauge symmetries and lead to a SUSY vacuum. Based on this idea, we propose a new class of SUSY magnetized orbifold models with three generations of quarks and leptons. Especially, we construct a model where the right-handed sneutrinos develop their vacuum expectation values which restore the supersymmetry but yield lepton number violating terms below the compactification scale, and show their phenomenological consequences.

    DOI

  • Flavor structure in SO(32) heterotic string theory

    Hiroyuki Abe, Tatsuo Kobayashi, Hajime Otsuka, Yasufumi Takano, Takuya H. Tatsuishi

    PHYSICAL REVIEW D   94 ( 12 ) 126020-1 - 126020-10  2016.12  [Refereed]

     View Summary

    We study the flavor structure in SO(32) heterotic string theory on six-dimensional tori with magnetic fluxes. Specifically, we focus on models with the flavor symmetries SU(3)(f) and Delta(27). In both models, we can realize the realistic quark masses and mixing angles.

    DOI

  • Dynamical supersymmetry breaking on magnetized tori and orbifolds

    Hiroyuki Abe, Tatsuo Kobayashi, Keigo Sumita

    NUCLEAR PHYSICS B   911   606 - 622  2016.10  [Refereed]

     View Summary

    We construct several dynamical supersymmetry breaking (DSB) models within a single ten-dimensional supersymmetric Yang-Mills (SYM) theory, compactified on magnetized tori with or without orbifolding. We study the case that the supersymmetry breaking is triggered by a strong dynamics of SU(NC) SYM theory with N-F flavors contained in the four-dimensional effective theory. We show several configurations of magnetic fluxes and orbifolds, those potentially yield, below the compactification scale, the field contents and couplings required for triggering DSB. We especially find a class of self-complete DSB models on orbifolds, where all the extra fields are eliminated by the orbifold projection and DSB successfully occurs within the given framework. Comments on some perspectives for associating the obtained DSB models with the other sectors, such as the visible sector and another hidden sector for, e.g., stabilizing moduli, are also given. (C) 2016 The Authors. Published by Elsevier B.V.

    DOI

  • Wavefunctions on magnetized branes in the conifold

    Hiroyuki Abe, Akane Oikawa, Hajime Otsuka

    JOURNAL OF HIGH ENERGY PHYSICS   16 ( 7 ) 0 - 34  2016.07  [Refereed]

     View Summary

    We study wavefunctions on D7-branes with magnetic fluxes in the conifold. Since some supersymmetric embeddings of D- branes on the AdS(5) x T-1,T-1 geometry are known, we consider one of the embeddings, especially the spacetime filling D7-branes in which (a part of) the standard model is expected to be realized. The explicit form of induced metric on the D7-branes allows us to solve the Laplace and Dirac equations to evaluate matter wavefunctions in extra dimensions analytically. We find that the zeromode wavefunctions can be localized depending on the configuration of magnetic fluxes on D7-branes, and show some phenomenological aspects.

    DOI

  • Gauge coupling unification in SO(32) heterotic string theory with magnetic fluxes

    Hiroyuki Abe, Tatsuo Kobayashi, Hajime Otsuka, Yasufumi Takano, Takuya H. Tatsuishi

    PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS   2016 ( 5 ) 053B01  2016.05  [Refereed]

     View Summary

    We study SO(32) heterotic string theory on a torus with magnetic fluxes. Non-vanishing fluxes can lead to non-universal gauge kinetic functions for SU(3) x SU(2) x U(1)gamma, which is an important feature of SO(32) heterotic string theory in contrast to the E-8 x E-8 theory. It is found that the experimental values of gauge couplings are realized with O(1) values of moduli fields based on realistic models with the SU(3) x SU(2) x U(1)gamma gauge symmetry and three chiral generations of quarks and leptons without chiral exotics.

    DOI

  • Superfield description of (4+2n)-dimensional SYM theories and their mixtures on magnetized tori

    Hiroyuki Abe, Tomoharu Horie, Keigo Sumita

    NUCLEAR PHYSICS B   900   331 - 365  2015.11  [Refereed]

     View Summary

    We provide a systematic way of dimensional reduction for (4 + 2n)-dimensional U(N) supersymmetric Yang-Mills (SYM) theories (n = 0, 1, 2, 3) and their mixtures compactified on two-dimensional tori with background magnetic fluxes, which preserve a partial N = 1 supersymmetry out of full N = 2, 3 or 4 in the original SYM theories. It is formulated in an N = 1 superspace respecting the unbroken supersymmetry, and the four-dimensional effective action is written in terms of superfields representing N = 1 vector and chiral multiplets, those arise from the higher-dimensional SYM theories. We also identify the dilaton and geometric moduli dependence of matter Kahler metrics and superpotential couplings as well as of gauge kinetic functions in the effective action. The results would be useful for various phenomenological/cosmological model buildings with SYM theories or D-branes wrapping magnetized tori, especially, with mixture configurations of them with different dimensionalities from each other. (C) 2015 The Authors. Published by Elsevier B.V.

    DOI

  • N = 1 superfield description of six-dimensional supergravity

    Abe, Hiroyuki, Sakamura, Yutaka, Sakamura, Yutaka, Yamada, Yusuke

    Journal of High Energy Physics   15 ( 10-181 ) 0 - 27  2015.10  [Refereed]

     View Summary

    © 2015, The Author(s). Abstract: We express the action of six-dimensional supergravity in terms of four-dimensional N=1$$ \mathcal{N}=1 $$ superfields, focusing on the moduli dependence of the action. The gauge invariance of the action in the tensor-vector sector is realized in a quite nontrivial manner, and it determines the moduli dependence of the action. The resultant moduli dependence is intricate, especially on the shape modulus. Our result is reduced to the known superfield actions of six-dimensional global SUSY theories and of five-dimensional supergravity by replacing the moduli superfields with their background values and by performing the dimensional reduction, respectively.

    DOI

  • Realistic three-generation models from SO(32) heterotic string theory

    Abe, Hiroyuki, Kobayashi, Tatsuo, Otsuka, Hajime, Takano, Yasufumi

    Journal of High Energy Physics   15 ( 09-056 ) 0 - 27  2015.09  [Refereed]

     View Summary

    © 2015, The Author(s). Abstract: We search for realistic supersymmetric standard-like models from SO(32) heterotic string theory on factorizable tori with multiple magnetic fluxes. Three chiral ganerations of quarks and leptons are derived from the adjoint and vector representations of SO(12) gauge groups embedded in SO(32) adjoint representation. Massless spectra of our models also include Higgs fields, which have desired Yukawa couplings to quarks and leptons at the tree-level.

    DOI

  • LHC phenomenology of natural MSSM with non-universal gaugino masses at the unification scale

    Abe, Hiroyuki, Kawamura, Junichiro, Omura, Yuji

    Journal of High Energy Physics   15 ( 08-089 ) 0 - 15  2015.08  [Refereed]

     View Summary

    © 2015, The Author(s). Abstract: In this letter, we study collider phenomenology in the supersymmetric Standard Model with a certain type of non-universal gaugino masses at the gauge coupling unification scale, motivated by the little hierarchy problem. In this scenario, especially the wino mass is relatively large compared to the gluino mass at the unification scale, and the heavy wino can relax the fine-tuning of the higgsino mass parameter, so-called μ-parameter. Besides, it will enhance the lightest Higgs boson mass due to the relatively large left-right mixing of top squarks through the renormalization group (RG) effect. Then 125 GeV Higgs boson could be accomplished, even if the top squarks are lighter than 1 TeV and the μ parameter is within a few hundreds GeV. The right-handed top squark tends to be lighter than the other sfermions due to the RG runnings, then we focus on the top squark search at the LHC. Since the top squark is almost right-handed and the higgsinos are nearly degenerate, 2b + ET miss channel is the most sensitive to this scenario. We figure out current and expected experimental bounds on the lightest top squark mass and model parameters at the gauge coupling unification scale.

    DOI

  • Matter coupled Dirac-Born-Infeld action in four-dimensional N=1 conformal supergravity

    Hiroyuki Abe, Yutaka Sakamura, Yusuke Yamada

    Physical Review D - Particles, Fields, Gravitation and Cosmology   92 ( 2 ) 025017-1 - 025017-8  2015.07  [Refereed]

     View Summary

    We construct the Dirac-Born-Infeld action in the context of N=1 conformal supergravity and its possible extensions including matter couplings. We especially focus on the Volkov-Akulov constraint, which is important to avoid ghost modes from the higher derivative terms. In the case with matter couplings, we find the modified D-term potential.

    DOI

  • D-brane instanton induced μ terms and their hierarchical structure

    Hiroyuki Abe, Tatsuo Kobayashi, Yoshiyuki Tatsuta, Shohei Uemura

    Physical Review D - Particles, Fields, Gravitation and Cosmology   92 ( 2 ) 026001-1 - 026001-6  2015.07  [Refereed]

     View Summary

    We study the μ-term matrix of Higgs pairs induced by the D-brane instanton effects in intersecting D6-brane models compactified on T6. It is found that the μ-term matrix has a certain permutation symmetry and its eigenvalues have large hierarchical structure without fine-tuning.

    DOI

  • Massive vector multiplet inflation with Dirac-Born-Infeld type action

    Hiroyuki Abe, Yutaka Sakamura, Yusuke Yamada

    PHYSICAL REVIEW D   91 ( 12 ) 125042-1 - 125042-9  2015.06  [Refereed]

     View Summary

    We investigate the inflation model with a massive vector multiplet in a case that the action of the vector multiplet is extended to the Dirac-Born-Infeld (DBI) type one. We show the massive DBI action in four-dimensional N = 1 supergravity and find that the higher-order corrections associated with the DBI extension make the scalar potential flat with a simple choice of the matter couplings. We also discuss the DBI extension of the new minimal Starobinsky model and find that it is dual to a special class of the massive DBI action.

    DOI

  • Towards natural inflation from weakly coupled heterotic string theory

    Hiroyuki Abe, Tatsuo Kobayashi, Hajime Otsuka

    PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS   2015 ( 6 ) 1 - 22  2015.06  [Refereed]

     View Summary

    We propose natural inflation from the heterotic string theory on the "Swiss-Cheese" Calabi-Yau manifold with multiple U(1) magnetic fluxes. Such multiple U(1) magnetic fluxes stabilize the same number of the linear combination of the universal axion and Kahler axions, and one of the Kahler axions is identified as the inflaton. This axion decay constant can be determined by the size of one-loop corrections to the gauge kinetic function of the hidden gauge groups, which leads effectively to the trans-Planckian axion decay constant consistent with the Planck data. During the inflation, the real parts of the moduli are also stabilized by employing the nature of the "Swiss-Cheese" Calabi-Yau manifold.

    DOI

  • Natural inflation with and without modulations in type IIB string theory

    Hiroyuki Abe, Tatsuo Kobayashi, Hajime Otsuka

    JOURNAL OF HIGH ENERGY PHYSICS   15 ( 4 ) 0 - 19  2015.04  [Refereed]

     View Summary

    We propose a mechanism for the natural inflation with and without modulation in the framework of type IIB string theory on toroidal orientifold or orbifold. We explicitly construct the stabilization potential of complex structure, dilaton and Kahler moduli, where one of the imaginary component of complex structure moduli becomes light which is identified as the inflaton. The inflaton potential is generated by the gaugino-condensation term which receives the one-loop threshold corrections determined by the field value of complex structure moduli and the axion decay constant of inflaton is enhanced by the inverse of one-loop factor. We also find the threshold corrections can also induce the modulations to the original scalar potential for the natural inflation. Depending on these modulations, we can predict several sizes of tensor-to-scalar ratio as well as the other cosmological observables reported by WMAP, Planck and/or BICEP2 collaborations.

    DOI

  • N=1 superfield description of vector-tensor couplings in six dimensions

    Hiroyuki Abe, Yutaka Sakamura, Yusuke Yamada

    JOURNAL OF HIGH ENERGY PHYSICS   15 ( 4 ) 0 - 25  2015.04  [Refereed]

     View Summary

    We express supersyrnmetric couplings among the vector and the tensor multiplets in six dimensions (6D) in terms of N = 1 superfields. The superfield description is derived from the invariant action in the projective superspace. The obtained expression is consistent with the known superfield actions of 6D supersymmetric gauge theory and 5D Chern-Simons theory after the dimensional reduction. Our result provides a crutial clue to the N = 1 superfield description of 6D supergravity.

    DOI

  • Illustrating SUSY breaking effects on various inflation mechanisms

    Hiroyuki Abe, Shuntaro Aoki, Fuminori Hasegawa, Yusuke Yamada

    JOURNAL OF HIGH ENERGY PHYSICS   1501 ( 1 ) 026  2015.01  [Refereed]

     View Summary

    We consider the supersymmetry breaking effects on typical inflation models with different types of Kahler potential. The critical size of supersymmetry-breaking scale, above which the flatness of the inflaton potential is spoiled, drastically changes model by model. We present the universal description of such effects in terms of a field-dependent scaling factor by which gravity-mediated supersymmetry breaking terms are suppressed or enhanced, based on the conformal supergravity framework. Such a description would be useful when we estimate them in constructing supersymmetric models of particle cosmology.

    DOI

  • Moduli inflation in five-dimensional supergravity models

    Hiroyuki Abe, Hajime Otsuka

    JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS   14 ( 11 ) 0 - 31  2014.11  [Refereed]

     View Summary

    We propose a simple,. but effective mechanism to realize an inflationary earl universe consistent with the observed WMAP, Planck and/or BICEP2 data, which would be incorporated in various supersymmetric models of elementary particles constructed in the (effective) five-dimensional spacetime. In our scenario, the inflaton field is identified with one of the moduli appearing when the fifth direction is compactified, and a successful cosmological inflation without the so-called eta problem can be achieved by a very simple moduli stabilization potential. We also discuss the related particle cosmology during and (just) after the inflation, such as the (no) cosmological moduli problem.

    DOI

  • Gaussian Froggatt-Nielsen mechanism on magnetized orbifolds

    Hiroyuki Abe, Tatsuo Kobayashi, Keigo Sumita, Yoshiyuki Tatsuta

    PHYSICAL REVIEW D   90 ( 10 ) 105006-1 - 105006-13  2014.11  [Refereed]

     View Summary

    We study the structure of Yukawa matrices derived from the supersymmetric Yang-Mills theory on magnetized orbifolds, which can realize the observed quark and charged lepton mass ratios as well as the Cabibbo-Kobayashi-Maswaka (CKM) mixing angles, even with a small number of tunable parameters and without any critical fine-tuning. As a reason behind this, we find that the obtained Yukawa matrices possess a Froggatt-Nielsen-like structure with Gaussian hierarchies, which provides a suitable texture for them favored by the experimental data.

    DOI

  • The Higgs boson mass and SUSY spectra in 10D SYM theory with magnetized extra dimensions

    Hiroyuki Abe, Junichiro Kawamura, Keigo Sumita

    NUCLEAR PHYSICS B   888   194 - 213  2014.11  [Refereed]

     View Summary

    We study the Higgs boson mass and the spectrum of supersymmetric (SUSY) particles in the wellmotivated particle physics model derived from a ten-dimensional supersymmetric Yang Mills theory compactified on three factorizable tori with magnetic fluxes. This model was proposed in a previous work, where the flavor structures of the standard model including the realistic Yukawa hierarchies are obtained from non-hierarchical input parameters on the magnetized background. Assuming moduli- and anomaly-mediated contributions dominate the soft SUSY breaking terms, we study the precise SUSY spectra and analyze the Higgs boson mass in this mode, which are compared with the latest experimental data. (C) 2014 The Authors. Published by Elsevier B.V.

    DOI

  • The 126 GeV Higgs boson mass and naturalness in (deflected) mirage mediation

    Hiroyuki Abe, Junichiro Kawamura

    JOURNAL OF HIGH ENERGY PHYSICS   14 ( 7 ) 0 - 26  2014.07  [Refereed]

     View Summary

    We study the mass of the lightest CP-even Higgs boson in the deflected mirage mediation that is a quite general framework of the mediation of supersymmetry breaking, incorporating the case where all of the modulus-, the anomaly-and the gauge-mediated contributions to the soft supersymmetry breaking parameters become sizable. We evaluate the degree of tuning the so-called parameter required for realizing a correct electroweak symmetry breaking and study how to accomplish both the observed Higgs boson mass and the relaxed fine-tuning. We identify the parameter space favored from such a perspective and show the superparticle mass spectrum with some input parameters inside the indicated region. The results here would be useful when we aim to prove the communication between the visible and the hidden sectors in supergravity and superstring models based on the recent observations.

    DOI

  • Non-Abelian discrete flavor symmetries of 10D SYM theory with magnetized extra dimensions

    Hiroyuki Abe, Tatsuo Kobayashi, Hiroshi Ohki, Keigo Sumita, Yoshiyuki Tatsuta

    JOURNAL OF HIGH ENERGY PHYSICS   14 ( 6 ) 0 - 40  2014.06  [Refereed]

     View Summary

    We study discrete flavor symmetries of the models based on a ten-dimensional supersymmetric Yang-Mills (10D SYM) theory compactified on magnetized tori. We assume non-vanishing non-factorizable fluxes as well as the orbifold projections. These setups allow model-building with more various flavor structures. Indeed, we show that there exist various classes of non-Abelian discrete flavor symmetries. In particular, we find that S-3 flavor symmetries can be realized in the framework of the magnetized 10D SYM theory for the first time.

    DOI

  • Flavor landscape of 10D SYM theory with magnetized extra dimensions

    Hiroyuki Abe, Tatsuo Kobayashi, Hiroshi Ohki, Keigo Sumita, Yoshiyuki Tatsuta

    JOURNAL OF HIGH ENERGY PHYSICS   14 ( 4 ) 0 - 25  2014.04  [Refereed]

     View Summary

    We study the flavor landscape of the visible sector of particle physics models based on a ten-dimensional super Yang-Mills theory compactified on magnetized tori preserving four-dimensional Nu = 1 supersymmetry. Recently, we constructed a semirealistic model which contains the minimal supersymmetric standard model (MSSM) using an ansatz of magnetic fluxes and orbifolding projections. However, we can consider more various configurations of magnetic fluxes and orbifolding projections preserving fourdimensional N = 1 supersymmetry. We research systematically such possibilities for leading to MSSM-like models and study their phenomenological aspects.

    DOI

  • Phenomenological aspects of 10D SYM theory with magnetized extra dimensions

    Hiroyuki Abe, Tatsuo Kobayashi, Hiroshi Ohki, Akane Oikawa, Keigo Sumita

    NUCLEAR PHYSICS B   870 ( 1 ) 30 - 54  2013.05  [Refereed]

     View Summary

    We present a particle physics model based on a ten-dimensional (10D) super Yang-Mills (SYM) theory compactified on magnetized tori preserving four-dimensional N = 1 supersymmetry. The low-energy spectrum contains the minimal supersymmetric standard model with hierarchical Yukawa couplings caused by a wavefunction localization of the chiral matter fields due to the existence of magnetic fluxes, allowing a semi-realistic pattern of the quark and the lepton masses and mixings. We show supersymmetric flavor structures at low energies induced by a moduli-mediated and an anomaly-mediated supersymmetry breaking. (C) 2013 Elsevier B.V. All rights reserved.

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  • The Higgs boson mass in a natural minimal supersymmetric standard model with nonuniversal gaugino masses at the grand unification theory scale

    Hiroyuki Abe, Junichiro Kawamura, Hajime Otsuka

    PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS   2013 ( 1 ) 1 - 13  2013.01  [Refereed]

     View Summary

    We identify a parameter region where the mass of the lightest CP-even Higgs boson resides at 124.4-126.8 GeV, and at the same time the degree of tuning a Higgsino-mass parameter (the so-called mu-parameter) is relaxed above 10% in the minimal supersymmetric standard model (MSSM) with soft supersymmetry breaking terms, by solving the full set of one-loop renormalization group equations numerically. It is found that certain nonuniversal values of gaugino-mass parameters at the so-called grand unification theory (GUT) scale similar to 10(16) GeV are important ingredients for the MSSM to predict, without severe fine-tuning, the Higgs boson mass similar to 125 GeV, indicated by recent observations at the Large Hadron Collider. We also show a typical superparticle spectrum in this parameter region.

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  • Superfield description of 10D SYM theory with magnetized extra dimensions

    Hiroyuki Abe, Tatsuo Kobayashi, Hiroshi Ohki, Keigo Sumita

    NUCLEAR PHYSICS B   863 ( 1 ) 1 - 18  2012.10  [Refereed]

     View Summary

    We present a four-dimensional (4D) N = 1 superfield description of supersymmetric Yang-Mills (SYM) theory in ten-dimensional (10D) spacetime with certain magnetic fluxes in compactified extra dimensions preserving partial N = 1 supersymmetry out of full N = 4. We derive a 41) effective action in N = 1 superspace directly from the 10D superfield action via dimensional reduction, and identify its dependence on dilaton and geometric moduli superfields. A concrete model for three generations of quark and lepton superfields are also shown. Our formulation would be useful for building various phenomenological models based on magnetized SYM theories or D-branes. (C) 2012 Elsevier B.V. All rights reserved.

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  • SUSY flavor structure of generic 5D supergravity models

    Hiroyuki Abe, Hajime Otsuka, Yutaka Sakamura, Yusuke Yamada

    EUROPEAN PHYSICAL JOURNAL C   72 ( 5 ) 1 - 22  2012.05  [Refereed]

     View Summary

    We perform a comprehensive and systematic analysis of the SUSY flavor structure of generic 5D supergravity models on S-1/Z(2) with multiple Z(2)-odd vector multiplets that generate multiple moduli. The SUSY flavor problem can be avoided due to contact terms in the 4D effective Kahler potential peculiar to the multi-moduli case. A detailed phenomenological analysis is provided based on an illustrative model.

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  • NON-ABELIAN DISCRETE FLAVOR SYMMETRIES ON ORBIFOLDS

    Hiroyuki Abe, Kang-Sin Choi, Tatsuo Kobayashi, Hiroshi Ohki, Manabu Sakai

    INTERNATIONAL JOURNAL OF MODERN PHYSICS A   26 ( 23 ) 4067 - 4082  2011.09  [Refereed]

     View Summary

    We study non-Abelian flavor symmetries on orbifolds, S-1/Z(2) and T-2/Z(3). Our extra dimensional models realize D-N, Sigma(2N(2)), Delta(3N(2)) and Delta(6N(2)) including A(4) and S-4. In addition, one can also realize their subgroups such as Q(N), T-7, etc. The S-3 flavor symmetry can be realized on both S-1/Z(2) and T-2/Z(3) orbifolds.

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  • Flavor structure from magnetic fluxes and non-Abelian Wilson lines

    Hiroyuki Abe, Kang-Sin Choi, Tatsuo Kobayashi, Hiroshi Ohki

    PHYSICAL REVIEW D   81 ( 12 ) 126003-1 - 126003-14  2010.06  [Refereed]

     View Summary

    We study the flavor structure of four-dimensional (4D) effective theories, which are derived from extra dimensional theories with magnetic fluxes and non-Abelian Wilson lines. We study zero-mode wave functions in generic case and compute Yukawa couplings as well as four-point couplings. In our models, we also discuss non-Abelian discrete flavor symmetries such as D-4, Delta(27), and Delta(54). The orbifold background is also studied.

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  • Magnetic flux, Wilson line, and orbifold

    Hiroyuki Abe, Kang-Sin Choi, Tatsuo Kobayashi, Hiroshi Ohki

    PHYSICAL REVIEW D   80 ( 12 ) 126006-1 - 126006-10  2009.12  [Refereed]

     View Summary

    We study torus/orbifold models with magnetic flux and Wilson line backgrounds. The number of zero modes and their profiles depend on those backgrounds. That has interesting implications from the viewpoint of particle phenomenology.

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  • Non-Abelian discrete flavor symmetries from magnetized/intersecting brane models

    Hiroyuki Abe, Kang-Sin Choi, Tatsuo Kobayashi, Hiroshi Ohki

    NUCLEAR PHYSICS B   820 ( 1-2 ) 317 - 333  2009.10  [Refereed]

     View Summary

    We study non-Abelian discrete flavor symmetries, which appear in magnetized brane models. For example, D-4, Delta(27) and Delta(54) flavor symmetries can appear with matter fields in several representations. We also study the orbifold background, where non-Abelian flavor symmetries are broken in a certain way. (C) 2009 Published by Elsevier B.V.

    DOI

  • Three generation magnetized orbifold models

    Hiroyuki Abe, Kang-Sin Choi, Tatsuo Kobayashi, Hiroshi Ohki

    NUCLEAR PHYSICS B   814 ( 1-2 ) 265 - 292  2009.06  [Refereed]

     View Summary

    We study three generation models in the four-dimensional spacetime, which can be derived from the ten-dimensional N = 1 super-Yang-Mills theory on the orbifold background with a non-vanishing magnetic flux. We classify the flavor structures and show possible patterns of Yukawa matrices. Some examples of numerical studies are also shown. (C) 2009 Elsevier B.V. All rights reserved.

    DOI

  • Higher order couplings in magnetized brane models

    Hiroyuki Abe, Kang-Sin Choi, Tatsuo Kobayashi, Hiroshi Ohki

    JOURNAL OF HIGH ENERGY PHYSICS   09 ( 6 ) 0 - 19  2009.06  [Refereed]

     View Summary

    We compute three-point and higher order couplings in magnetized brane models. We show that higher order couplings are written as products of three-point couplings. This behavior is the same as higher order amplitudes by conformal field theory calculations e. g. in intersecting D-brane models.

    DOI

  • Duality cascade of softly broken supersymmetric theories

    Hiroyuki Abe, Tetsutaro Higaki, Tatsuo Kobayashi, Kazutoshi Ohta, Yuji Omura, Haruhiko Terao

    PHYSICAL REVIEW D   79 ( 4 ) 045003-1 - 045003-11  2009.02  [Refereed]

     View Summary

    We study the duality cascade of softly broken supersymmetric theories. We investigate the renormalization group (RG) flow of SUSY breaking terms as well as supersymmetric couplings. It is found that the magnitudes of SUSY breaking terms are suppressed in most regimes of the RG flow through the duality cascade. At one stage of cascading, the gaugino mass of the strongly coupled sector and scalar masses converge to certain values, which are determined by the gauge coupling and the gaugino mass of the weakly coupled sector. At the next stage, the strongly and weakly coupled sectors are interchanged with each other. We also show the possibility that cascading would be terminated by the gauge symmetry breaking, which is induced by the so-called B-term.

    DOI

  • Flavor structure with multi-moduli in 5D supergravity

    Hiroyuki Abe, Yutaka Sakamura

    PHYSICAL REVIEW D   79 ( 4 ) 045005-1 - 045005-16  2009.02  [Refereed]

     View Summary

    We study five-dimensional supergravity on S-1/Z(2) with a physical Z(2)-odd vector multiplet, which yields an additional modulus other than the radion. We derive four-dimensional effective theory and find additional terms in the Kahler potential that are peculiar to the multi-moduli case. Such terms can avoid tachyonic soft scalar masses at tree level, which are problematic in the single modulus case. We also show that the flavor structure of the soft terms are different from that in the single modulus case when hierarchical Yukawa couplings are generated by wave function localization in the fifth dimension. We present a concrete model that stabilizes the moduli at a supersymmetry breaking Minkowski minimum and show the low-energy sparticle spectrum.

    DOI

  • Magnetized orbifold models

    Hiroyuki Abe, Tatsuo Kobayashi, Hiroshi Ohki

    Journal of High Energy Physics   08 ( 09-043 ) 0 - 20  2008.09  [Refereed]

    DOI

  • Nonperturbative moduli superpotential with positive exponents

    Hiroyuki Abe, Tetsutaro Higaki, Tatsuo Kobayashi, Osamu Seto

    PHYSICAL REVIEW D   78 ( 2 ) 025007-1 - 025007-8  2008.07  [Refereed]

     View Summary

    We study nonperturbative moduli superpotentials with positive exponents, i.e. the form like Ae(aT) with a positive constant a and the modulus T. These effects can be generated, e.g., by D-branes which have negative Ramond-Ramond charge of the lower-dimensional D-brane. The scalar potentials including such terms have quite a rich structure. There are several local minima with different potential energies and a high barrier, whose height is of O(M-p(4)). We discuss their implications from the viewpoints of cosmology and particle phenomenology, e.g. the realization of inflation models, avoiding the overshooting problem. This type of potential would be useful to realize the inflation and low-energy supersymmetry breaking.

    DOI

  • Moduli stabilization in 5D gauged supergravity with universal hypermultiplet and boundary superpotentials

    Hiroyuki Abe, Yutaka Sakamura

    NUCLEAR PHYSICS B   796 ( 1-2 ) 224 - 245  2008.06  [Refereed]

     View Summary

    We study a four-dimensional effective theory of the five-dimensional (5D) gauged supergravity with a universal hypermultiplet and perturbative superpotential terms at the orbifold fixed points. Among eight independent isometrics of the scalar manifold, we focus on three directions for gauging by the graviphoton. The class of models we consider includes the 5D heterotic M-theory and the supersymmetric Randall-Sundrum model as special limits of the gauging parameters. We analyze the vacuum structure of such models, especially the nature of moduli stabilization, from the viewpoint of the effective theory. We also discuss the uplifting of supersymmetric anti-de Sitter vacua. (c) 2007 Elsevier B.V. All rights reserved.

    DOI

  • Dynamically sequestered F-term uplifting in extra dimension

    Hiroyuki Abe, Tetsutaro Higaki, Tatsuo Kobayashi, Yuji Omura

    Journal of High Energy Physics   08 ( 04-072 ) 0 - 24  2008.04  [Refereed]

    DOI

  • Metastable supersymmetry breaking vacua from conformal dynamics

    Hiroyuki Abe, Tatsuo Kobayashi, Yuji Omura

    PHYSICAL REVIEW D   77 ( 6 ) 065001-1 - 065001-5  2008.03  [Refereed]

     View Summary

    We study the scenario that conformal dynamics leads to metastable supersymmetry breaking vacua. At a high energy scale, the superpotential is not R-symmetric and has a supersymmetric minimum. However, conformal dynamics suppresses several operators along renormalization group flow toward the infrared fixed point. Then we can find an approximately R-symmetric superpotential, which has a metastable supersymmetry breaking vacuum, and the supersymmetric vacuum moves far away from the metastable supersymmetry breaking vacuum. We show a 4D simple model. Furthermore, we can construct 5D models with the same behavior, because of the AdS/CFT duality.

    DOI

  • Off-shell dimensional reduction of 5D orbifold supergravity

    Hiroyuki Abe

    素粒子論研究   116 ( 1 ) A146 - A148  2008

    DOI

  • Sequestering in models of F-term uplifting

    Hiroyuki Abe

    SUPERSYMMETRY AND THE UNIFICATION OF FUNDAMENTAL INTERACTIONS   1078   411 - 413  2008  [Refereed]

     View Summary

    We discuss the nature of sequestering supersymmetry breaking sectors in a certain class of moduli stabilization in supergravity/string models, where a negative vacuum energy of the nonperturbative moduli potential is canceled by dynamically generated F-terms. Two illustrating examples are shown to sketch the issues around the supersymmetry breaking, flavors and sequestering within such a framework.

    DOI

  • More about f-term uplifting

    Hiroyuki Abe, Tetsutaro Higaki, Tatsuo Kobayashi

    PHYSICAL REVIEW D   76 ( 10 ) 105003-1 - 105003-12  2007.11  [Refereed]

     View Summary

    We study moduli stabilization and a realization of de Sitter vacua in generalized F-term uplifting scenarios of the Kachru-Kallosh-Linde-Trivedi-type anti-de Sitter vacuum, where the uplifting sector X directly couples to the light Kahler modulus T in the superpotential through, e.g., stringy instanton effects. F-term uplifting can be achieved by a spontaneous supersymmetry breaking sector, e.g., the Polonyi model, the O'Raifeartaigh model, and the Intriligator-Seiberg-Shih model. Several models with the X-T mixing are examined, and qualitative features in most models even with such mixing are almost the same as those in the Kachru-Kallosh-Linde-Trivedi scenario. One of the quantitative changes, which are relevant to the phenomenology, is a larger hierarchy between the modulus mass m(T) and the gravitino mass m(3/2), i.e., m(T)/m(3/2)=O(a(2)), where a similar to 4 pi(2). In spite of such a large mass, the modulus F term is suppressed not like F-T=O(m(3/2)/a(2)), but like F-T=O(m(3/2)/a) for ln(M-Pl/m(3/2))similar to a, because of an enhancement factor coming from the X-T mixing. Then we typically find a mirage-mediation pattern of gaugino masses of O(m(3/2)/a), while the scalar masses would be generically of O(m(3/2)).

    DOI

  • R-symmetry, supersymmetry breaking and metastable vacua in global and local supersymmetric theories

    Hiroyuki Abe, Tatsuo Kobayashi, Yuji Omura

    Journal of High Energy Physics   07 ( 11-044 ) 0 - 28  2007.11  [Refereed]

    DOI

  • TeV scale partial mirage unification and neutralino dark matter

    Hiroyuki Abe, Yeong Gyun Kim, Tatsuo Kobayashi, Yasuhiro Shimizu

    Journal of High Energy Physics   07 ( 09-107 ) 0 - 16  2007.09  [Refereed]

    DOI

  • Relaxed fine-tuning in models with nonuniversal gaugino masses

    Hiroyuki Abe, Tatsuo Kobayashi, Yuji Omura

    PHYSICAL REVIEW D   76 ( 1 ) 015002-1 - 015002-8  2007.07  [Refereed]

     View Summary

    We study, in a bottom-up approach, the fine-tuning problem between soft supersymmetry (SUSY) breaking parameters and the mu term for the successful electroweak symmetry breaking in the minimal supersymmetric standard model. It is shown that certain ratios among nonuniversal gaugino masses at the grand unified theory (GUT) scale are necessary to reduce fine-tuning. In addition, when all the gaugino masses are regarded as independent ones in their origins, a small gluino mass M-3 less than or similar to 120 GeV and a nonvanishing A term A(t)similar to O(M-3) associated with top squarks are also required at the GUT scale as well as the nonuniversality. On the other hand, when we consider some UV theory, which fixes ratios of soft SUSY breaking parameters as certain values aside from the overall magnitude, heavier spectra are allowed. It is favored that the gluino and W-ino masses are almost degenerate at the weak scale, while a wider region of b-ino mass is favorable.

    DOI

  • Supersymmetry breaking in a warped slice with Majorana-type masses

    Hiroyuki Abe, Yutaka Sakamura

    Journal of High Energy Physics   07 ( 03-106 ) 0 - 21  2007.03  [Refereed]

    DOI

  • Patterns of supersymmetry breaking in moduli-mixing racetrack model

    Hiroyuki Abe

    AIP Conference Proceedings   903   517 - 520  2007

     View Summary

    We show some structures of moduli stabilization and supersymmetry breaking caused by gaugino condensations with the gauge couplings depending on two moduli which often appear in the four-dimensional effective theories of superstring compactifications. © 2007 American Institute of Physics.

    DOI

  • Supersymmetry breaking in moduli-mixing racetrack model

    安倍 博之

    素粒子論研究   114 ( 4 ) D104  2007

    DOI

  • Supersymmetry breaking in moduli-mixing racetrack model

    Hiroyuki Abe

    素粒子論研究   114 ( 5 ) E138 - E141  2007

    DOI

  • Supersymmetry breaking in moduli-mixing racetrack model

    安倍 博之

    素粒子論研究   114 ( 6 ) F37  2007  [Refereed]

    DOI

  • Roles of Z(2)-odd N=1 multiplets in off-shell dimensional reduction of five-dimensional supergravity

    Hiroyuki Abe, Yutaka Sakamura

    PHYSICAL REVIEW D   75 ( 2 ) 025018-1 - 025018-17  2007.01  [Refereed]

     View Summary

    We discuss the dimensional reduction of five-dimensional supergravity compactified on S-1/Z(2) keeping the N=1 off-shell structure. In particular, we clarify the roles of the Z(2)-odd N=1 multiplets in such an off-shell dimensional reduction. Their equations of motion provide constraints on the Z(2)-even multiplets and extract the zero modes from the latter. The procedure can be applied to a wide range of models and performed in a background-independent way. We demonstrate it in some specific models.

    DOI

  • Moduli stabilization, F-term uplifting, and soft supersymmetry breaking terms

    Hiroyuki Abe, Tetsutaro Higaki, Tatsuo Kobayashi, Yuji Omura

    PHYSICAL REVIEW D   75 ( 2 ) 025019-1 - 025019-7  2007.01  [Refereed]

     View Summary

    We study moduli stabilization with F-term uplifting. As a source of uplifting F-term, we consider spontaneous supersymmetry breaking models, e.g. the Polonyi model and the Intriligator-Seiberg-Shih model. We analyze potential minima by requiring almost vanishing vacuum energy and evaluate the size of modulus F-term. We also study soft SUSY-breaking terms. In our scenario, the mirage mediation is dominant in gaugino masses. Scalar masses can be comparable with gaugino masses or much heavier, depending on couplings with spontaneous supersymmetry breaking sector.

    DOI

  • Remark on integrating out heavy moduli in flux compactification

    Hiroyuki Abe, Tetsutaro Higaki, Tatsuo Kobayashi

    Physical Review D   74 ( 4 ) 045012-1 - 045012-8  2006.08  [Refereed]

    DOI

  • Consistent dimensional reduction of five-dimensional off-shell supergravity

    Hiroyuki Abe, Yutaka Sakamura

    Physical Review D   73 ( 12 ) 125013-1 - 125013-13  2006.06  [Refereed]

    DOI

  • Moduli-mixing racetrack model

    H Abe, T Higaki, T Kobayashi

    NUCLEAR PHYSICS B   742 ( 43103.0 ) 187 - 207  2006.05  [Refereed]

     View Summary

    We study supersymmetric models with double gaugino condensations in the hidden sector, where the gauge couplings depend on two light moduli of superstring theory. We perform a detailed analysis of this class of model and show that there is no stable supersymmetric minimum with finite vacuum values of moduli fields. Instead, we find that the supersymmetry breaking occurs with moduli stabilized and negative vacuum energy. That yields moduli-dominated soft supersymmetry breaking terms. To realize slightly positive (or vanishing) vacuum energy, we add uplifting potential. We discuss uplifting does not change qualitatively the vacuum expectation values of moduli and the above feature of supersymmetry breaking. (c) 2006 Elsevier B.V. All rights reserved.

    DOI

  • Kachru-Kallosh-Linde-Trivedi-type models with moduli-mixing superpotential

    Hiroyuki Abe, Tetsutaro Higaki, Tatsuo Kobayashi

    Physical Review D   73 ( 4 ) 046005-1 - 046005-13  2006.02  [Refereed]

    DOI

  • Scherk-Schwarz SUSY breaking from the viewpoint of 5D conformal supergravity

    Hiroyuki Abe, Yutaka Sakamura

    Journal of High Energy Physics   06 ( 02-014 ) 0 - 16  2006.02  [Refereed]

    DOI

  • Effective N=1 description of 5D conformal supergravity

    Hiroyuki Abe, Yutaka Sakamura

    素粒子論研究   112 ( 5 ) E59 - E61  2006

    DOI

  • Dynamical radion superfield in 5D action

    H Abe, Y Sakamura

    PHYSICAL REVIEW D   71 ( 10 ) 105010-1 - 105010-15  2005.05  [Refereed]

     View Summary

    We derive 5D N = 1 superspace action including the radion superfield. The radion is treated as a dynamical field and identified as a solution of the equation of motion even in the presence of the radius stabilization mechanism. Our derivation is systematic and based on the superconformal formulation of 5D supergravity. We can read off the couplings of the dynamical radion superfield to the matter superfields from our result. The correct radion mass can be obtained by calculating the radion potential from our superspace action.

    DOI

  • Fayet-Iliopoulos terms in 5D orbifold supergravity

    Hiroyuki Abe

    素粒子論研究   110 ( 6 ) F67 - F69  2005

    DOI

  • Gauged U(1)(R) supergravity on orbifold

    H Abe

    Particles, Strings, and Cosmology   805   342 - 345  2005  [Refereed]

     View Summary

    We discuss a gauged U(I)R supergravity on five-dimensional orbifold (S-1/Z(2)) in which a Z(2)-even U(1) gauge field takes part in the U(1)(R) gauging, and show the structure of Fayet-Iliopoulos (FI) terms allowed in such model. Some physical consequences of the FI terms are examined.

    DOI

  • Gauged U(1)R symmetries and Fayet-Iliopoulos terms in 5D orbifold supergravity

    Hiroyuki Abe, Kiwoon Choi

    Journal of High Energy Physics   04 ( 12-069 ) 0 - 18  2004.12  [Refereed]

    DOI

  • Superfield description of 5D supergravity on general warped geometry

    Hiroyuki Abe, Yutaka Sakamura

    Journal of High Energy Physics   04 ( 10-013 ) 0 - 25  2004.10  [Refereed]

    DOI

  • Fayet-Iliopoulos terms in 5D orbifold supergravity

    Hiroyuki Abe, Kiwoon Choi, Ian-Woo Kim

    Journal of High Energy Physics   04 ( 09-001 ) 0 - 26  2004.09  [Refereed]

    DOI

  • Scherk-Schwarz supersymmetry breaking for quasi-localized matter fields and supersymmetry flavor violation

    Hiroyuki Abe, Kiwoon Choi, Kwang-Sik Jeong, Ken-ichi Okumura

    Journal of High Energy Physics   04 ( 09-015 ) 0 - 33  2004.09  [Refereed]

    DOI

  • Dynamical symmetry breaking on a brane with bulk gauge theory

    Hiroyuki Abe

    素粒子論研究   109 ( 1 ) A37 - A38  2004

    DOI

  • Fayet-Iliopoulos terms in 5D orbifold supergravity

    Hiroyuki Abe

    Supersymmetry and unification of fundamental interactions. Proceedings, 12th International Conference, SUSY 2004, Tsukuba, Japan, June 17-23, 2004 (Edited by K. Hagiwara, J. Kanzaki, N. Okada. Tsukuba)     813 - 816  2004  [Refereed]

  • Wave-function profile and SUSY breaking in 5D model with Fayet-Iliopoulos terms

    H Abe, T Higaki, T Kobayashi

    PROGRESS OF THEORETICAL PHYSICS   109 ( 5 ) 809 - 830  2003.05  [Refereed]

     View Summary

    We systematically study VEVs of a gauge scalar field Sigma in a bulk U(1) vector multiplet and scalar fields in brane/bulk hypermultiplets charged under U(1) in the 5D S-1/Z(2) orbifold model with generic FI terms. A non-trivial VEV of Sigma generates bulk mass terms for U(1) charged fields, and their zero modes have non-trivial profiles. In particular, in the SUSY-breaking case, bosonic and fermionic zero modes have Gaussian profiles. Such non-trivial profiles are useful to explain hierarchical couplings. A toy model for SUSY breaking is studied, and it yields sizable D-term contributions to scalar masses. Because the overall magnitude of D-term contributions is the same everywhere in the bulk and also on both branes, we have to take into account these contributions and other SUSY-breaking terms to obtain a realistic description. We also give profiles and mass eigenvalues of higher modes.

    DOI

  • Field localization in warped gauge theories

    H Abe, T Kobayashi, N Maru, K Yoshioka

    PHYSICAL REVIEW D   67 ( 4 ) 045019-1 - 045019-14  2003.02  [Refereed]

     View Summary

    We present four-dimensional gauge theories that describe physics on five-dimensional curved (warped) backgrounds, which includes bulk fields with various spins (vectors, spinors, and scalars). Field theory on the AdS(5) geometry is examined as a simple example of our formulation. Various properties of bulk fields on this background, e.g., the mass spectrum and field localization behavior, can be achieved within a fully four-dimensional framework. Moreover, that gives a localization mechanism for massless vector fields. We also consider supersymmetric cases, and show in particular that the conditions on bulk masses imposed by supersymmetry on warped backgrounds are derived from a four-dimensional supersymmetric theory on the flat background. As a phenomenological application, models are shown to generate hierarchical Yukawa couplings. Finally, we discuss possible underlying mechanisms which dynamically realize the required couplings to generate curved geometries.

    DOI

  • Schwinger-Dyson 方程式を用いたbulk Yang-Mills 理論によるbrane 上での対称性の動的破れの解析

    安倍 博之

    素粒子論研究   107 ( 4 ) D45  2003

    DOI

  • Wave-function profile and SUSY breaking in 5D model with Fayet-Iliopoulos term

    安倍 博之

    素粒子論研究   108 ( 1 ) A21  2003

    DOI

  • Schwinger-Dyson analysis of dynamical symmetry breaking on a brane with bulk Yang-Mills theory

    H Abe, T Inagaki

    PHYSICAL REVIEW D   66 ( 8 ) 085001-1 - 085001-12  2002.10  [Refereed]

     View Summary

    The dynamically generated fermion mass is investigated in a flat brane world with (4+delta)-dimensional bulk space-time, and in the Randall-Sundrum (RS) brane world. We consider the bulk Yang-Mills theory interacting with a fermion confined on a four-dimensional brane. Based on the effective theory below a reduced cutoff scale on the brane, we formulate the Schwinger-Dyson equation of the brane fermion propagator. By using the improved ladder approximation we numerically solve the Schwinger-Dyson equation and find that the dynamical fermion mass is near the reduced cutoff scale on the brane for the flat brane world with deltagreater than or equal to3 and for the RS brane world. In the RS brane world Kaluza-Klein excited modes of the bulk gauge field localize around the y=piR brane and this enhances dynamical symmetry breaking on the brane. The decay constant of the fermion and the antifermion composite operator can be taken to be of the order of the electroweak scale, much smaller than the Planck scale. Therefore the electroweak mass scale can be realized from only the Planck scale in the RS brane world due to fermion and antifermion pair condensation. That is a dynamical realization of the Randall-Sundrum model which solves the weak-Planck hierarchy problem.

    DOI

  • Chiral phase transition of bulk Abelian gauge theories in the Randall-Sundrum background

    H Abe, K Fukazawa, T Inagaki

    PROGRESS OF THEORETICAL PHYSICS   107 ( 5 ) 1047 - 1060  2002.05  [Refereed]

     View Summary

    The chiral phase transition of strong-coupling Abelian gauge theories is investigated in brane world models. It is assumed that the gauge boson propagates in an extra dimension, i.e. we consider bulk gauge theories. The phase structure is analytically evaluated by using low-energy effective theories. We also numerically solve the ladder Schwinger-Dyson equation for the full fermion propagator including Kaluza-Klein (KK) excitation modes of the gauge field. It is found that the chiral phase transition is of second order, and the critical value of the coupling constant is obtained. The extra dimension has a large influence on the chiral phase transition. It is studied how the number of KK modes affects the chiral phase transition.

    DOI

  • Randall-Sundrum 時空中のU(1) ゲージ理論の相構造について

    安倍 博之

    素粒子論研究   104 ( 4 ) D34 - D35  2002

    DOI

  • Fermion mass generation in extra dimensions

    Hiroyuki Abe

    素粒子論研究   102 ( 6 ) F125 - F134  2001

    DOI

  • Dynamical fermion masses under the influence of Kaluza-Klein fermions in extra dimensions

    H Abe, H Miguchi, T Muta

    MODERN PHYSICS LETTERS A   15 ( 6 ) 445 - 454  2000.02  [Refereed]

     View Summary

    The dynamical fermion mass generation in the four-dimensional brane is discussed in a model with five-dimensional Kaluza-Klein fermions in interaction with four-dimensional fermions. It is found that the dynamical fermion masses are generated beyond the critical radius of the compactified extra dimensional space and may be made small compared with the masses of the Kaluza-Klein modes.

    DOI

  • Path-integral formulation of Casimir effects in supersymmetric quantum electrodynamics

    H Abe, J Hashida, T Muta, A Purwanto

    MODERN PHYSICS LETTERS A   14 ( 16 ) 1033 - 1042  1999.05  [Refereed]

     View Summary

    The path-integral method of calculating the Casimir energy between two parallel conducting plates is developed within the framework of supersymmetric quantum electrodynamics at vanishing temperature as well as at finite temperature. The choice of the suitable boundary condition for the photino on the plates is argued and the physically acceptable condition is adopted which eventually breaks the supersymmetry. The photino mass term is introduced in the Lagrangian and the photino mass dependence of the Casimir energy and pressure is fully investigated.

    DOI

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Books and Other Publications

  • ``Dynamical fermion masses under the infuence of Kaluza-Klein fermions in Randall-Sundrum background'' in Fluctuating Paths and Fields (Editorial Board: W. Janke, A. Pelster, H.-J. Schmidt, M. Bachmann)

    Hiroyuki Abe, Tomohiro Inagaki, Taizo Muta( Part: Other)

    World Scientific, Singapore  2001

Awards

  • Particle Physics Medal: Young Scientist Award in Theoretical Particle Physics

    2009.03  

Research Projects

  • Search for realistic supersymmetric models in higher-dimensions based on high-energy/cosmological observations

    Project Year :

    2016.04
    -
    2019.03
     

     View Summary

    We have searched for realistic supersymmetric models in higher-dimensional spacetime based on high-energy/cosmological observations and obtained phenomenological constraints on them.These provide various guidelines to find the unified theory beyond the standard model of elementary particles. During the search, especially, we noticed the existence of new effects which can heavily affect phenomenological features of the model. We developed general formulations of these effects and analyzed them

  • Particle phenomenology of supergravity/string models on nontrivial gauge background

    Project Year :

    2013.04
    -
    2016.03
     

     View Summary

    We studied phenomenological features of higher-dimensional supersymmetric Yang-Mills (SYM) theories on magnetized background in detail, which appear in the low-energy effective theories of supergravity/string theories on nontrivial gauge backgrounds. We identified and classified the configurations of background magnetic fluxes, those agree with the current experimental/observational data. Furthermore, we have proposed some extensions of the models as well as of the tools for analyzing them, from the perspective of consistencies with superstring theories. The results illuminate phenomenological side of the higher-dimensional SYM theory, which is considered as a promising candidate for the unified theory of elementary particles from various perspectives. The outcomes also provide a lot of guidelines for constructing a realistic particle-physics model based on superstring theories

Presentations

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Specific Research

  • 高エネルギー実験と宇宙観測に基づく現実的な高次元超対称模型の探索

    2019   小林達夫, 阪村豊, 青木俊太朗, 今井颯亮, 竹本賢太

     View Summary

    素粒子統一理論の有力候補とされる高次元超対称理論に基づき、物質場の現実的なスペクトラムの生成と、現象論的に要請される超対称性の自発的破れを伴う余剰次元の安定化を、単一の枠組みで実現可能な理論のパラメータ領域の絞り込みを行った。このような領域ではヒッグスボソンにも非自明な世代構造が現れる傾向があり、これが高エネルギー実験に及ぼす影響についても考察した。さらに、高次元超対称模型の4次元有効理論は必然的に、拡張された超対称性をもつことが知られており、本研究では通常の2倍の超電荷をもつN=2拡張超対称理論における超対称性の破れの構造を調べた。以上の成果をもとに、同模型が持つパラメータの許容領域を更に絞っていくことで、素粒子統一理論の探求に向けた強い指針が得られると期待している。

  • 超重力・超弦理論に基づく素粒子模型の現象論

    2012  

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    磁場を持つ6次元トーラス上にコンパクト化された10次元超対称ゲージ理論のゼロモードの一部を素粒子標準理論の粒子群に同定した場合には、物質粒子の世代数が磁束の本数で決まり、更にはこれら物質場の波動関数が磁場の効果で余剰次元空間に局在するため、4次元有効理論における湯川結合定数の階層構造が生じる。このような機構に基づき、本研究では観測されている素粒子の質量固有値や混合値の階層性を再現するような磁場とウィルソンラインの値を同定し、更にそれらの下での素粒子現象論を解析した。超対称性を局所化した場合には余剰次元の幾何学的構造を司る力学的自由度はモジュライと呼ばれる超対称多重項として有効理論に現れるが、ここでは特にモジュライが伝達する超対称性の破れの大きさに対して実験から強い制限がかけられることを示した。これは超弦理論に基づく素粒子模型の構築に重要な指針を与える結果として論文[1]に発表し学術雑誌に掲載されると共に、日本物理学会では研究協力者によりこれらの成果に関する発表が行われた。また、2012年初夏に大型ハドロン衝突型加速器(LHC)においてヒッグス粒子とみられる新粒子が発見されその質量が同定されたが、これが実際にヒッグス粒子である場合には最小超対称標準理論のパラメターに対して厳しい制限が加えられることになる。LHCで未だ超対称粒子が発見されていないという事実からこれらの粒子の質量は電弱スケールよりもかなり大きくなければならないが、このような状況で観測されたヒッグス粒子の質量を再現するためには多くの場合パラメターの微調整が必要になる。本研究ではゲージ粒子の超対称パートナーの質量比に対するこれらの制限を精密に解析し、パラメターの微調整なしにヒッグス粒子の質量値が再現できるパラメター領域を同定した。これは背後にあるより基本的な理論を考える上で大変重要な指針となる。これらの成果は論文[2]として発表し学術雑誌に掲載された。

  • 超重力・超弦理論に基づく素粒子模型の現象論

    2011  

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    互いに排他的な側面をもつ素粒子標準理論と重力理論とを統合する試みにおいて、基本構成要素を点粒子から紐に拡張して考える超弦理論は、そのような統一理論の最有力候補として盛んに研究されている。超弦理論が矛盾なく定義できるのは時空の次元が10の場合であり、超対称性と呼ばれる、ボーズ場とフェルミ場の入れ換えの下での不変性も要求され、その低エネルギー有効理論としては高次元時空の超重力理論や超対称ヤン・ミルズ理論が現れることが知られている。本研究では、超弦理論の予言する超対称性と余剰次元空間の存在に注目し、超重力理論や超弦理論に軸足を置いた素粒子模型の構築と、それらの現象論を系統的に解析する手法の開発に向けた研究を行った。まずボトムアップ・アプローチでは、フレーバー電荷の違いから観測されている素粒子の世代間階層構造を説明することが可能な5次元超重力理論に基づく模型を構築し、そこでの超対称性の破れの構造を精密に解析することで、今後の発見が期待されている超対称パートナー粒子の性質を明らかにした。この結果では、超重力理論でしばしば問題となる超対称スカラー粒子の不安定性やそれらの粒子が引き起こす過剰な世代間遷移の問題を回避可能なフレーバー電荷の組み合わせが存在することが示され、これは超重力理論に基づく素粒子模型の構築に対して重要な指針を与える。これらの成果に関しては International Workshop: Extra Dimensions in the Era of the LHC (12-14 December 2011, Osaka University) と日本物理学会第67回年次大会において研究協力者が発表を行った。また、成果をまとめた論文[1]は学術雑誌に掲載された。一方、トップダウン・アプローチでは、10次元超対称ヤン・ミルズ理論の余剰次元に磁束が存在するような場合に、作用を4次元時空の超対称性の言葉で書き表した後に次元縮減を行うことを提案し、これに基づき4次元有効理論を系統的に導出する手法の開発を行った。背景磁場が存在する場合の様々なDブレーン配位に対する低エネルギー有効理論の導出にこの手法を応用することが可能であると考えられるため、超弦理論に基づく素粒子模型の構築とその現象論的解析に有用である。これらの成果に関しては、日本物理学会2011年秋季大会・第67回年次大会において研究協力者が発表を行った。また、成果をまとめた論文[2]は学術雑誌に掲載された。

  • 素粒子の超弦模型における世代構造の研究

    2010  

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    超弦理論は重力を含めた素粒子の統一理論の有力候補であると考えられているが、これまでに観測されている素粒子の様々な性質をこれが完全に予言できるのかどうかは未だ分かっておらず、超弦理論の現象論的解析は重要な研究課題である。超弦理論の低エネルギー有効理論として素粒子標準理論のようなカイラルな理論が得られるためには、低エネルギーの4次元時空で左右対称性が破れなければならない。これまでに考えられてきた素粒子の超弦模型では、このような左右非対称性を生成するメカニズムとしてオービフォルドと呼ばれる射影空間がよく用いられている。本研究ではこのような空間がもつ非可換離散対称性を素粒子世代構造の観点から分類した。これは超弦理論や高次元時空の場の理論に基づく素粒子模型における世代構造を解析する際に有用であると考えられる。これらの成果は論文[1]にまとめ学術雑誌に掲載された。また、これとは別にII型超弦理論の低エネルギー有効理論として素粒子の標準理論を再現するような超弦模型の構築において、交差するDブレーン系とその双対である磁場をもつDブレーンの系が有望であると考えられているが、後者では素粒子の世代構造を決定する湯川結合の値が有効理論の枠内で精度よく計算可能であることが知られている。本研究では、磁場をもつ超対称非可換ゲージ理論を超空間で定式化することにより、磁場をもつDブレーン系の4次元有効理論を系統的に導出する方法を考案した。これにより既知の素粒子の世代構造を再現する磁場に対して未知の超対称粒子の世代構造を同定することができるため、超弦模型の検証に有用であると考えられる。これらの成果に関しては日本物理学会2010年秋季大会で研究協力者が発表した。

  • 高次元超重力理論における素粒子世代構造の研究

    2009  

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    超弦理論の予言する超対称性と余剰次元の存在に注目し、低エネルギー有効理論として得られる高次元超重力理論において、素粒子標準理論の世代構造を実現する機構を解明するという目的で研究を行った。本研究では、超弦理論から標準理論へと向かうトップダウン・アプローチと、逆に標準理論から超弦理論へと向かうボトムアップ・アプローチという、2つの方向から解析を行った。トップダウン・アプローチでは、超弦理論の交叉Dブレーン系に双対な記述として知られている、余剰次元に背景磁場が存在するような系を考え、磁場により引き起こされる波動関数の局在化とウィルソンラインの存在及びオービフォルド化の相乗効果が、クォーク・レプトンの質量や混合などの世代構造にどのような影響を与えるかを系統的に調べた。そして、質量行列の対称性と磁束の数及びウィルソンラインの値の関係を明らかにして、その主要な部分を論文[1]に、詳細は論文[2]に発表した。この研究成果に関して、特に富士吉田で開催されたSummer Institute 2009における共同研究者との議論は大変有意義であった。また、余剰次元に磁場を持つ超対称ゲージ理論の低エネルギー有効理論を系統的に導出する手法の開発にも重要な進展が得られた。一方のボトムアップ・アプローチでは、これまでのオービフォルド上の5次元超重力理論の解析を、物質場がモジュライ多重項の下でより一般的な電荷を持っている場合に拡張して、その低エネルギー有効理論の世代構造を同定した。

 

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