Upward muon signals at neutrino detectors as a probe of dark matter properties (2009)
Hisano, Junji, Nakayama, Kazunori, Yang, Masaki J. S.
We study upward muon flux at neutrino detectors such as Super-Kamiokande resulting from high-energy neutrinos produced by the dark matter annihilation/decay at the Galactic center. In particular, we...
Cosmic Rays from Dark Matter Annihilation and Big-Bang Nucleosynthesis (2009)
Hisano, Junji, Kawasaki, Masahiro, Kohri, Kazunori, Moroi, Takeo, Nakayama, Kazunori
Recent measurements of cosmic-ray electron and positron fluxes by PAMELA and ATIC experiments may indicate the existence of annihilating dark matter with large annihilation cross section. We show...
Discriminating Electroweak-ino Parameter Ordering at the LHC and Its Impact on LFV Studies (2008)
Hisano, Junji, Nojiri, Mihoko M., Sreethawong, Warintorn
Current limit on the dark matter relic abundance may suggest that $|\mu|$ should be smaller than prediction in the minimal supergravity scenario (mSUGRA) for moderate $m_0$ and $m_{1/2}$. The...
A Complete Analysis of "Flavored" Electric Dipole Moments in Supersymmetric Theories (2008)
Hisano, Junji, Nagai, Minoru, Paradisi, Paride
The Standard Model predictions for the hadronic and leptonic electric dipole moments (EDMs) are well far from the present experimental resolutions, thus, the EDMs represent very clean probes of New...
Hisano, Junji, Kawasaki, Masahiro, Kohri, Kazunori, Nakayama, Kazunori
The excess of cosmic-ray electron and positron fluxes measured by the PAMELA satellite and ATIC balloon experiments may be interpreted as the signals of the dark matter annihilation or decay into...
A Realistic Extension of Gauge-Mediated SUSY-Breaking Model with Superconformal Hidden Sector (2008)
Asano, Masaki, Hisano, Junji, Okada, Takashi, Sugiyama, Shohei
The sequestering of supersymmetry (SUSY) breaking parameters, which is induced by superconformal hidden sector, is one of the solutions for the mu/B_mu problem in gauge-mediated SUSY-breaking...
Positron/Gamma-Ray Signatures of Dark Matter Annihilation and Big-Bang Nucleosynthesis (2008)
Hisano, Junji, Kawasaki, Masahiro, Kohri, Kazunori, Nakayama, Kazunori
The positron excess observed by the PAMELA experiment may come from dark matter annihilation, if the annihilation cross section is large enough. We show that the dark matter annihilation scenarios to...
Charged Lepton-Flavor Violation in Beyond-Standard Models (2008)
I discuss charged lepton-flavor violation in physics beyond the standard model and review topics related to it.
CP Violation in B_s Mixing in the SUSY SU(5) GUT with Right-handed Neutrinos (2008)
Hisano, Junji, Shimizu, Yasuhiro
It is recently announced by the {\bf Ut}{\it fit} collaboration that the CP phase of the $B_s$ mixing amplitude, $\phi_{B_s}$, deviates more than $3 \sigma$ from the standard-model prediction. In...
Upperbound on Squark Masses in Gauge-Mediation Model with Light Gravitino (2008)
Hisano, Junji, Nagai, Minoru, Sugiyama, Shohei, Yanagida, T. T.
We examine stabilities of our supersymmetry-breaking false vacuum in a low-energy direct gauge mediation model of SUSY breaking. The stability required in the high-temperature early universe leads to...
Hisano, Junji, Nagai, Minoru, Senami, Masato, Sugiyama, Shohei
Recently Murayama and Nomura proposed a simple scheme to construct the gauge mediation models, using metastable supersymmetry breaking vacua. It has a possibility to predict the ultra light gravitino...
Revisiting Signature of Minimal Gauge Mediation (2007)
Hisano, Junji, Shimizu, Yasuhiro
We revisit phenomenology of the minimal gauge-mediated model. This model is motivated from the SUSY CP and flavor problems. A specific feature of this model is that \tan\beta is naturally large,...
Electric Dipole Moments in PseudoDirac Gauginos (2006)
Hisano, Junji, Nagai, Minoru, Naganawa, Tatsuya, Senami, Masato
The SUSY CP problem is one of serious problems in construction of realistic supersymmetric standard models. We consider the problem in a framework in which adjoint chiral multiplets are introduced...
Non-perturbative Effect on Thermal Relic Abundance of Dark Matter (2006)
Hisano, Junji, Matsumoto, Shigeki, Nagai, Minoru, Saito, Osamu, Senami, Masato
We point out that thermal relic abundance of the dark matter is strongly altered by a non-perturbative effect called the Sommerfeld enhancement, when constituent particles of the dark matter are...
Constraining SuperWIMPy and Warm Subhalos with Future Submillilensing (2006)
Hisano, Junji, Inoue, Kaiki Taro, Takahashi, Tomo
We propose to observe QSO-galaxy strong lens systems to give a new constraint on the damping scale of the initial fluctuations. We find that the future observation of submilliarc scale astrometric...
New Two-loop Contributions to Hadronic EDMs in the MSSM (2006)
Hisano, Junji, Nagai, Minoru, Paradisi, Paride
Flavor-changing terms with CP-violating phases in the quark sector may contribute to the hadronic electric dipole moments (EDMs). However, within the Standard Model (SM), the source of CP violation...
Heavy Wino-like Neutralino Dark Matter Annihilation into Antiparticles (2005)
Hisano, Junji, Matsumoto, Shigeki, Saito, Osamu, Senami, Masato
The lightest neutralino is a viable dark matter (DM) candidate. In this paper we study indirect detection of the wino-like neutralino DM using positrons and antiprotons from the annihilation in the...
Hadronic EDM Constraints on Orbifold GUTs (2005)
Hisano, Junji, Kakizaki, Mitsuru, Nagai, Minoru
We point out that the null results of the hadronic electric dipole moment (EDM) searches constrain orbifold grand unified theories (GUTs), where the GUT symmetry and supersymmetry (SUSY) are both...
Investigation of Possible Dark Matter Direct Detection in Electron Accelerators (2005)
Hisano, Junji, Nagai, Minoru, Nojiri, Mihoko M., Senami, Masato
We investigate a possibility of neutralino dark matter (DM) direct detection in the future electron accelerators. That is counting of high p_T electron recoil events by neutralinos in halo. If...
Hisano, Junji, Matsumoto, Shigeki., Nojiri, Mihoko M., Saito, Osamu
Detection of gamma rays from dark matter annihilation in the galactic center is one of the feasible techniques to search for dark matter. We evaluate the gamma ray flux in the case that the dark...
Hadronic and leptonic EDMs in SUSY GUTs are reviewed in this article.
CP violation in supersymmetric seesaw models (2004)
In supersymmetric (SUSY) extensions of the seesaw mechanism the neutrino Yukawa interaction induces the flavor and CP violating sfermion mass terms via the radiative correction. In this article we...
Flavor and CP violation in the SUSY SU(5) GUT with the right-handed neutrinos (2004)
The neutrino flavor mixing may induce rich flavor and CP violating phenomena in the SUSY GUTs. In this paper we discuss the hadronic EDMs and the correlation among low-energy processes induced by the...
Hadronic EDMs in SUSY SU(5) GUTs with Right-handed Neutrinos (2004)
Hisano, Junji, Kakizaki, Mitsuru, Nagai, Minoru, Shimizu, Yasuhiro
We discuss hadronic EDM constraints on the neutrino sector in the SUSY SU(5) GUT with the right-handed neutrinos. The hadronic EDMs are sensitive to the right-handed down-type squark mixings,...
Direct Detection of the Wino- and Higgsino-like Neutralino Dark Matters at One-Loop Level (2004)
Hisano, Junji, Matsumoto, Shigeki, Nojiri, Mihoko M., Saito, Osamu
The neutralino-nucleon (\tilde{\chi}^0-N) scattering is an important process for direct dark matter searches. In this paper we discuss one-loop contributions to the cross section in the wino-like and...
Hadronic EDMs induced by the strangeness and constraints on supersymmetric CP phases (2004)
Hisano, Junji, Shimizu, Yasuhiro
We consider hadronic CP violation induced by chromoelectric dipolemoments (CEDMs) of light quarks and the QCD theta parameter ($?overline{?theta}$). We concentrate on the strange quark CEDM...
Flavor and CP Violation Induced by Atmospheric Neutrino Mixing (2004)
Neutrino oscillation experiments suggest existence of new flavor-violating interactions in high energy scale. It may be possible to probe them by the flavor- and CP-violating processes in leptons and...
Hisano, Junji, Shimizu, Yasuhiro
The correlation between the CP asymmetry in $B\to \phi K_s$ ($S_{\phi K_s}$) and the chromoelectric dipole moment (CEDM) of strange quark ($d_s^C$), which is constrained by the electric dipole moment...
Explosive Dark Matter Annihilation (2003)
Hisano, Junji, Matsumoto, Shigeki, Nojiri, Mihoko M.
If the Dark Matter (DM) in the Universe has interactions with the standard-model particle, the pair annihilation may give the imprints in the cosmic ray. In this paper we study the pair annihilation...
A Detailed Study of the Gluino Decay into the Third Generation Squarks at the CERN LHC (2003)
Hisano, Junji, Kawagoe, Kiyotomo, Nojiri, Mihoko M.
In supersymmetric models a gluino can decay into tb\tilde{\chi}^{\pm}_1 through a stop or a sbottom. The decay chain produces an edge structure in the m_{tb} distribution. Monte Carlo simulation...
GUT relation in Neutrino-Induced Flavor Physics in SUSY SU(5) GUT (2003)
Hisano, Junji, Shimizu, Yasuhiro
In the SUSY SU(5) GUT with the right-handed neutrinos, the neutrino Yukawa coupling induces the flavor-violating mass terms for the right-handed down squarks and left-handed sleptons, and they lead...
Hisano, Junji, Matsumoto, Sh., Nojiri, Mihoko M.
The neutralino pair annihilation into two photons in our galactic halo gives a robust dark matter signal, since it would give a quasi-monotonic gamma ray. This process is radiatively-induced, and the...
A New Parametrization of the Seesaw Mechanism and Applications in Supersymmetric Models (2002)
Ellis, John, Hisano, Junji, Raidal, Martti, Shimizu, Yasuhiro
We present a new parametrization of the minimal seesaw model, expressing the heavy-singlet neutrino Dirac Yukawa couplings $(Y_\nu)_{ij}$ and Majorana masses $M_{N_i}$ in terms of effective...
Scenery from the Top: Study of the Third Generation Squarks at CERN LHC (2002)
Hisano, Junji, Kawagoe, Kiyotomo, Kitano, Ryuichiro, Nojiri, Mihoko M.
In the minimal supersymmetric standard model (MSSM) properties of the third generation sfermions are important from the viewpoint of discriminating the SUSY breaking models and in the determination...
Slepton Oscillation at Large Hadron Collider (2002)
Hisano, Junji, Kitano, Ryuichiro, Nojiri, Mihoko M.
Measurement of Lepton-Flavor Violation (LFV) in the minimal SUSY Standard Model (MSSM) at Large Hadron Collider (LHC) is studied based on a realistic simulation. We consider the LFV decay of the...
The stau exchange contribution to muon g-2 in the decoupling solution (2001)
Cho, Gi-Chol, Haba, Naoyuki, Hisano, Junji
We study the possibility that the lepton-flavor changing process can induce the suitable magnitude of the muon anomalous magnetic moment (g_\mu -2) in the decoupling solution to the flavor problem in...
Lepton Electric Dipole Moments in Non-Degenerate Supersymmetric Seesaw Models (2001)
Ellis, John, Hisano, Junji, Raidal, Martti, Shimizu, Yasuhiro
In the context of supersymmetric seesaw models of neutrino masses with non-degenerate heavy neutrinos, we show that Dirac Yukawa interactions N^c_i (Y_nu)_{ij} L_j H_2 induce large threshold...
CP Violation in the Minimal Supersymmetric Seesaw Model (2001)
Ellis, John, Hisano, Junji, Lola, Smaragda, Raidal, Martti
We study CP violation in the lepton sector of the supersymmetric extension of the Standard Model with three generations of massive singlet neutrinos with Yukawa couplings $Y_\nu$ to lepton doublets,...
Neutrino masses, muon g-2, and lepton-flavour violation in the supersymmetric see-saw model (2001)
In the light of the recent muon (g_mu-2) result by the E821 experiment at the Brookhaven National Laboratory, we study the event rates of the charged lepton-flavour-violating (LFV) processes in the...
Hisano, Junji, Nojiri, Mihoko M., Okada, Nobuchika
The gauge-mediated SUSY-breaking (GMSB) model needs entropy production at a relatively low temperature in the thermal history of the Universe for the unwanted relics to be diluted. This requires a...
Natural Effective Supersymmetry (2000)
Hisano, Junji, Kurosawa, Kiichi, Nomura, Yasunori
Much heavier sfermions of the first-two generations than the other superparticles provide a natural explanation for the flavor and CP problems in the supersymmetric standard model (SUSY SM). However,...
Bulk Standard Model in the Randall-Sundrum Background (1999)
Chang, Sanghyeon, Hisano, Junji, Nakano, Hiroaki, Okada, Nobuchika, Yamaguchi, Masahiro
We discuss issues in an attempt to put the Standard Model (SM) in five-dimensional anti-de Sitter spacetime compactified on $S^1/Z_2$. The recently-proposed approach to the gauge hierarchy problem by...
On Effective Theory of Brane World with Small Tension (1999)
Hisano, Junji, Okada, Nobuchika
The five dimensional theory compactified on $S^1$ with two ``branes'' (two domain walls) embedded in it is constructed, based on the field-theoretic mechanism to generate the ``brane''. Some light...
Lepton-Flavor Violation in the Left-handed Slepton Production at Future Lepton Colliders (1998)
Hisano, Junji, Nojiri, Mihoko M., Shimizu, Yasuhiro, Tanaka, Minoru
The Super-Kamiokande atmospheric neutrino data suggest existence of the large lepton-flavor violating (LFV) interaction in the higher energy scale. If the minimal supersymmetric standard model is...
Upper Bound on R_b in Two Higgs Doublet Model from Lepton Universality (1997)
Hisano, Junji, Kiyoura, Shingo, Murayama, Hitoshi
It has been known that $R_b$ can be enhanced in the two Higgs doublet model if $\tan \beta$ is large. We point out that a similar enhancement in $\Gamma(Z \to \tau^+ \tau^-)$ is large enough to place...
Hard gluon emission from colored scalar pairs\break in e^+ e^- annihilation (1996)
Hikasa, Ken-ichi, Hisano, Junji
We study QCD correction to the pair production of colored scalar particles in electron-positron annihilation with an emphasis on gluon emission in the final state. We discuss the usefulness of...