257 citations · 2.2k across the 81 of their papers we have counts for
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Precise Estimate of Charged Higgsino/Wino Decay Rate
Masahiro Ibe, Yuhei Nakayama, Satoshi Shirai
Higgsinos and Winos in the supersymmetric Standard Model are prime candidates for dark matter due to their weakly interacting nature. The mass differences between their charged com…
Gravitational Positivity for Phenomenologists: Dark Gauge Boson in the Swampland
Katsuki Aoki, Toshifumi Noumi, Ryo Saito +4
The gravitational positivity bound gives quantitative "swampland'' constraints on low-energy effective theories inside theories of quantum gravity. We give a comprehensive discussi…
Enhanced prospects for direct detection of inelastic dark matter from a non-galactic diffuse component
Gonzalo Herrera, Alejandro Ibarra, Satoshi Shirai
In some scenarios, the dark matter particle predominantly scatters inelastically with the target, producing a heavier neutral particle in the final state. In this class of scenario…
Precise Estimate of Charged Wino Decay Rate
Masahiro Ibe, Masataka Mishima, Yuhei Nakayama +1
The Wino is an triplet Majorana fermion and a well-motivated dark matter candidate. The mass difference between the charged and the neutral Winos is small than…
More on Fake GUT
Masahiro Ibe, Satoshi Shirai, Motoo Suzuki +2
It is remarkable that the matter fields in the Standard Model (SM) are apparently unified into the representations. A straightforward explanation of this fact is t…
QCD Axion Search with ILC Beam Facility
Hajime Fukuda, Hidetoshi Otono, Satoshi Shirai
One of the most promising methods to search for axions is a light-shining-through-walls (LSW) experiment. In this work, we discuss the possibility of performing an LSW experiment a…
On the Detection of QCD Axion Dark Matter by Coherent Scattering
Hajime Fukuda, Satoshi Shirai
The QCD axion is a promising candidate of the dark matter. In this paper, we discuss elastic scattering processes between nucleons and the QCD axion dark matter. We point out that…
Cosmological Constraints on Dark Scalar
Masahiro Ibe, Shin Kobayashi, Yuhei Nakayama +1
We discuss cosmological constraints on a dark scalar particle mixing with the Standard Model Higgs boson. We pay particular attention to the dark scalar production process when the…
Probing Relativistic Axions from Transient Astrophysical Sources
Joshua Eby, Satoshi Shirai, Yevgeny V. Stadnik +1
Emission of relativistic axions from transient sources, such as axion star explosions, can lead to observable signatures. We show that axion bursts from collapsing axion stars can…
Thermal Real Scalar Triplet Dark Matter
Taisuke Katayose, Shigeki Matsumoto, Satoshi Shirai +1
Real scalar triplet dark matter, which is known to be an attractive candidate for a thermal WIMP, is comprehensively studied paying particular attention to the Sommerfeld effect on…
Muon in Gauge Mediation without SUSY CP Problem
Masahiro Ibe, Shin Kobayashi, Yuhei Nakayama +1
We discuss gauge mediated supersymmetry breaking models which explain the observed muon anomalous magnetic moment and the Higgs boson mass simultaneously. The successful explanatio…
On Stability of Fermionic Superconducting Current in Cosmic String
Masahiro Ibe, Shin Kobayashi, Yuhei Nakayama +1
Recently, the chiral superconductivity of the cosmic string in the axion model has gathered attention. The superconductive nature can alter the standard understanding of the cosmol…
Non-perturbative Effects on Electroweakly Interacting Massive Particles at Hadron Collider
Taisuke Katayose, Shigeki Matsumoto, Satoshi Shirai
Electroweakly Interacting Massive Particles (EWIMPs), in other words, new massive particles that are charged under the electroweak interaction of the Standard Model (SM), are often…
Cosmological Constraint on Vector Mediator of Neutrino-Electron Interaction in light of XENON1T Excess
Masahiro Ibe, Shin Kobayashi, Yuhei Nakayama +1
Recently, the XENON1T collaboration reported an excess in the electron recoil energy spectrum. One of the simplest new physics interpretation is a new neutrino-electron interaction…
Precise WIMP Dark Matter Abundance and Standard Model Thermodynamics
Ken'ichi Saikawa, Satoshi Shirai
A weakly interacting massive particle (WIMP) is a leading candidate of the dark matter. The WIMP dark matter abundance is determined by the freeze-out mechanism. Once we know the p…
Cosmological Constraint on Dark Photon from
Masahiro Ibe, Shin Kobayashi, Yuhei Nakayama +1
A new U(1) gauge symmetry is the simplest extension of the Standard Model and has various theoretical and phenomenological motivations. In this paper, we study the cosmological con…
Cornering Higgsino: Use of Soft Displaced Track
Hajime Fukuda, Natsumi Nagata, Hideyuki Oide +2
Higgsino has been intensively searched for in the LHC experiments in recent years. Currently, there is an uncharted region beyond the LEP Higgsino mass limit where the mass splitti…
Role of Future Lepton Colliders for Fermionic Z-portal Dark Matter
Dilip Kumar Ghosh, Taisuke Katayose, Shigeki Matsumoto +3
The fermionic Z-portal dark matter model suffers from severe constraints from direct detection experiments. However, a narrow parameter space around the Z-funnel region is beyond t…
FAKE GUT
Masahiro Ibe, Satoshi Shirai, Motoo Suzuki +1
The perfect fit of the matter fields of the Standard Model (SM) into the multiplets has strongly supported the idea of the Grand Unified Theory (GUT) for decades. In this p…
How Heavy can Neutralino Dark Matter be?
Hajime Fukuda, Feng Luo, Satoshi Shirai
What is the upper limit of the mass of the neutralino dark matter whose thermal relic is consistent with the observation? If the neutralino dark matter and colored sparticles are e…
Indirect Probe of Electroweak-Interacting Particles with Mono-Lepton Signatures at Hadron Colliders
Shigeki Matsumoto, Satoshi Shirai, Michihisa Takeuchi
Electroweak-interacting massive particles (EWIMPs) exist in a broad class of new physics models beyond the Standard Model. Searching for such particles is one of most primary goal…
Primordial gravitational waves, precisely: The role of thermodynamics in the Standard Model
Ken'ichi Saikawa, Satoshi Shirai
In this paper, we revisit the estimation of the spectrum of primordial gravitational waves originated from inflation, particularly focusing on the effect of thermodynamics in the S…
Low-scale Gauge Mediation after LHC Run 2
Xiaochuan Lu, Satoshi Shirai
We study low-scale gauge mediated supersymmetry breaking models with a very light gravitino of mass eV. The cosmological upper bound on the gravitino mass and the…
Indirect Probe of Electroweakly Interacting Particles at the High-Luminosity Large Hadron Collider
Shigeki Matsumoto, Satoshi Shirai, Michihisa Takeuchi
Many extensions of the standard model (SM) involve new massive particles charged under the electroweak gauge symmetry. The electroweakly interacting new particles affect various SM…