Counting papers with at most 25 authors, so collaboration author lists do not stand in for the people here.
- The University of TokyoJP4.5k papers
- Yukawa Institute for Theoretical PhysicsJP2.7k papers
- The University of OsakaJP2.3k papers
- Nagoya UniversityJP2.2k papers
- High Energy Accelerator Research OrganizationJP2.2k papers
- Centre National de la Recherche ScientifiqueFR2.1k papers
- Tokyo Institute of TechnologyJP2k papers
- University of TsukubaJP1.7k papers
- Brookhaven National LaboratoryUS1.6k papers
- Stony Brook UniversityUS1.5k papers
- Waseda UniversityJP1.5k papers
- Commissariat à l'Énergie Atomique et aux Énergies AlternativesFR1.5k papers
31 papers · 2 filters
Optimized Perturbation Theory at Finite Temperature--- Two-Loop Analysis---
S. Chiku
We study the optimized perturbation theory (OPT) at finite temperature, which is a self-consistent resummation method. Firstly, we generalize the idea of the OPT to optimize the co…
Radiative decay of a massive particle and the non-thermal process in primordial nucleosynthesis
M. Kawasaki, K. Kohri, Takeo Moroi
We consider the effects on big bang nucleosynthesis (BBN) of the radiative decay of a long-lived massive particle. If high-energy photons are emitted after the BBN epoch ($t \sim 1…
Can we distinguish SUSY breaking terms between weakly and strongly coupled heterotic string theories ?
Tatsuo Kobayashi
We study soft SUSY breaking terms in heterotic M-theory. We show that both weakly and strongly coupled heterotic string models lead to the same relations of soft SUSY breaking term…
Neutralino Warm Dark Matter
J. Hisano, K. Kohri, M. M. Nojiri
In the supersymmetric (SUSY) standard model, the lightest neutralino may be the lightest SUSY particle (LSP), and it is is a candidate of the dark matter in the universe. The LSP d…
Restricted flavor structure of soft SUSY breaking trilinear couplings
T. Kobayashi, O. Vives
We analyze the flavor structure of the trilinear couplings in the different theoretical models of SUSY breaking. We generically obtain A_{ij}= A^L_i + A^R_j in all the models exami…
Brane Fluctuation and New Counting Rules for Kaluza-Klein Towers
Masako Bando, Tatsuya Noguchi
In models with extra dimensions, branes have been usually treated as solid bodies though they are prohibited by the relativity. In the previous letter, we proposed a method of taki…
Direct Detection of Neutralino Dark Matter and the Anomalous Dipole Moment of the Muon
Manuel Drees, Yeong Gyun Kim, Tatsuo Kobayashi +1
We compare predictions for the spin-independent contribution to the neutralino-proton scattering cross section $\sig$ and for the anomalous magnetic dipole moment of the muon, $a_μ…
Chiral Symmetry Restoration and the sigma-meson
Tetsuo Hatsuda, Teiji Kunihiro
The sigma-meson, which is at best a broad resonance in the vacuum, may suffer a substantial red-shift and appear as a soft and narrow collective mode at finite temperature and bary…
Off-shell d=5 Supergravity coupled to Matter-Yang-Mills System
T. Kugo, K. Ohashi
We present an off-shell formulation of matter-Yang-Mills system coupled to supergravity in five dimensional space-time. We give an invariant action for the general system of vector…
Kaluza-Klein Mediated Supersymmetry Breaking
Tatsuo Kobayashi, Koichi Yoshioka
We discuss a framework for communicating supersymmetry breaking to the visible sector where the radius modulus, which determines the size of extra dimensions, has an auxiliary vacu…
Contribution of sigma meson pole to K_L-K_S mass difference
K. Terasaki
The hypothesis of sigma meson pole dominance in the Delta I = 1/2 K -> pi pi amplitudes is tested by using the K_L-K_S mass difference.
In-medium pi-pi Correlation Induced by Partial Restoration of Chiral Symmetry
D. Jido, T. Hatsuda, T. Kunihiro
We show that both the linear and the non-linear chiral models give an enhancement of the pi-pi cross section near the 2pi threshold in the scalar-iso-scalar (I=J=0) channel in nucl…
Gravitational Stability and Extra Timelike Dimensions
Satoshi Matsuda, Shigenori Seki
Tachyonic Kaluza-Klein modes normally appear from the compactification of extra timelike dimensions with scale and lead to some instabilities of physical systems. We calculate…
Fermion Mass Hierarchies and Small Mixing Angles from Extra Dimensions
Masako Bando, Tatsuo Kobayashi, Tatsuya Noguchi +1
In this paper we study renormalization-group evolutions of Yukawa matrices enhanced by Kaluza-Klein excited modes and analyze their infrared fixed-point structure. We derive necess…
Scrutinizing LSP Dark Matter at the LHC
Manuel Drees, Yeong Gyun Kim, Mihoko M. Nojiri +3
We show that LHC experiments might well be able to determine all the parameters required for a prediction of the present density of thermal LSP relics from the Big Bang era. If the…
Asymptotic Behavior of Perturbations in Randall-Sundrum Brane-World
Takahiro Tanaka
The asymptotic behavior of metric perturbations in Randall-Sundrum infinite brane world is carefully investigated. Perturbations generated by matter fields on the brane are shown t…
Parton Distributions in the Virtual Photon Target and Factorization Scheme Dependence
Ken Sasaki, Tsuneo Uematsu
We investigate parton distributions in the virtual photon target, both polarized and unpolarized, up to the next-leading order (NLO) in QCD. Parton distributions can be predicted c…
Supergravity Tensor Calculus in 5D from 6D
T. Kugo, K. Ohashi
Supergravity tensor calculus in five spacetime dimensions is derived by dimensional reduction from the d=6 superconformal tensor calculus. In particular, we obtain an off-shell hyp…
Softly Broken Supersymmetric Gauge-Higgs-Yukawa Theories as Renormalizable Composite Models
Tatsuo Kobayashi, Haruhiko Terao
We examine the (softly broken) supersymmetric gauge-Higgs-Yukawa theories satisfying the compositeness conditions at a certain scale. In these theories the Higgs superfields can be…
Infrared alignment of SUSY flavor structures
Tatsuo Kobayashi, Koichi Yoshioka
The various experimental bounds on flavor-changing interactions severely restrict the low-energy flavor structures of soft supersymmetry breaking parameters. In this work, we show…
New RG-invariants of Soft Supersymmetry Breaking Parameters
Tatsuo Kobayashi, Koichi Yoshioka
We study new renormalization-group invariant quantities of soft supersymmetry breaking parameters other than the ratio of gaugino mass to gauge coupling squared by using the spurio…
Novel Relations between Lepton and Quark Mixings
Masako Bando, Taichiro Kugo, Koichi Yoshioka
A novel relation is found which gives the 2-3 lepton mixing angle in terms of quark masses and CKM mixing: \tanθ_{μτ}=(m_b/m_s)V_{cb}. This relation, which is remarkably in good ag…
Quark mixings and flavor changing interactions with singlet quarks
Katsuichi Higuchi, Katsuji Yamamoto
Aspects of the quark mixings and flavor changing interactions are investigated in electroweak models with singlet quarks. The effects on the ordinary quark mixing are determined in…
RG-invariant Sum Rule in a Generalization of Anomaly Mediated SUSY Breaking Models
Marcela Carena, Katri Huitu, Tatsuo Kobayashi
We study a generalization of anomaly-mediated supersymmetry breaking (AMSB) scenarios, under the assumption that the effects of the high-scale theory do not completely decouple and…