75 citations · 1.1k across the 46 of their papers we have counts for
46 papers
Wave-Packet Effects: A Solution for Isospin Anomalies in Vector-Meson Decay
Kenzo Ishikawa, Osamu Jinnouchi, Kenji Nishiwaki +1
There is a long-standing anomaly in the ratio of the decay width for to that for at the level of . A similar anomaly exis…
Gradient-flowed order parameter for spontaneous gauge symmetry breaking
Kengo Kikuchi, Kenji Nishiwaki, Kin-ya Oda
The gauge-invariant two-point function of the Higgs field at the same spacetime point can make a natural gauge-invariant order parameter for spontaneous gauge symmetry breaking. Ho…
New effect in wave-packet scattering of quantum fields
Kenzo Ishikawa, Kenji Nishiwaki, Kin-ya Oda
We report calculations of a wave-packet amplitude of the two-body scattering , which leads to the measured probability in realistic experiments. We elucidate the dec…
Scalar scattering amplitude in Gaussian wave-packet formalism
Kenzo Ishikawa, Kenji Nishiwaki, Kin-ya Oda
We compute an -channel scalar scattering in the Gaussian wave-packet formalism at the tree-level. We find that wave-packet effects, including shifts of the…
Dynamical generation of quark/lepton mass hierarchy in an extra dimension
Yukihiro Fujimoto, Kouhei Hasegawa, Kenji Nishiwaki +4
We show that the observed quark/lepton mass hierarchy can be realized dynamically on an interval extra dimension with point interactions. In our model, the positions of the point i…
Simultaneous explanation of and anomalies in vectorlike compositeness
Shinya Matsuzaki, Kenji Nishiwaki, Kei Yamamoto
We address the presently reported significant flavor anomalies in the and meson systems such as the CP violating Kaon decay () and lepton-flavor universality violatio…
Extended supersymmetry with central charges in higher dimensional Dirac action
Yukihiro Fujimoto, Kouhei Hasegawa, Kenji Nishiwaki +3
A new realization of extended quantum-mechanical supersymmetry (QM SUSY) with central extension is investigated. We first show that two different sets of () supercharges…
Simultaneous interpretation of and anomalies in terms of chiral-flavorful vectors
Shinya Matsuzaki, Kenji Nishiwaki, Kei Yamamoto
We address the presently reported significant flavor anomalies in the Kaon and meson systems such as the CP violating Kaon decay () and lepton-flavor universality violati…
Extended supersymmetry in Dirac action with extra dimensions
Yukihiro Fujimoto, Kouhei Hasegawa, Kenji Nishiwaki +3
We investigate a new realization of extended quantum-mechanical supersymmetry. We first show that an quantum-mechanical supersymmetry is hidden in the four-dimensio…
Seesaw mechanism in magnetic compactifications
Makoto Ishida, Kenji Nishiwaki, Yoshiyuki Tatsuta
In this paper, we explore a new avenue to a natural explanation of the observed tiny neutrino masses with a dynamical realization of the three-generation structure in the neutrino…
Dynamical generation of fermion mass hierarchy in an extra dimension
Yukihiro Fujimoto, Takashi Miura, Kenji Nishiwaki +1
We propose a new mechanism to produce a fermion mass hierarchy dynamically in a model with a singlet generation of fermions. A five dimensional gauge theory on an interval with poi…
Phenomenology of flavorful composite vector bosons in light of anomalies
Shinya Matsuzaki, Kenji Nishiwaki, Ryoutaro Watanabe
We analyze the flavor structure of composite vector bosons arising in a model of vectorlike technicolor, often called hypercolor (HC), with eight flavors that form a one-family con…
Brane-localized masses in magnetic compactifications
Makoto Ishida, Kenji Nishiwaki, Yoshiyuki Tatsuta
We discuss effects of the brane-localized mass terms on the fixed points of the toroidal orbifold under the presence of background magnetic fluxes, where multiple lowest…
Di-higgs enhancement by neutral scalar as probe of new colored sector
Koji Nakamura, Kenji Nishiwaki, Kin-ya Oda +2
We study a class of models in which the Higgs pair production is enhanced at hadron colliders by an extra neutral scalar. The scalar particle is produced by the gluon fusion via a…
CP-violating phase on magnetized toroidal orbifolds
Tatsuo Kobayashi, Kenji Nishiwaki, Yoshiyuki Tatsuta
We study the CP-violating phase of the quark sector in the flavor model on with non-vanishing magnetic fluxes, where properties of possible origins…
Supersymmetry in 6d Dirac Action
Yukihiro Fujimoto, Kouhei Hasegawa, Kenji Nishiwaki +2
We investigate a 6d Dirac fermion on a rectangle. It is found that the 4d spectrum is governed by supersymmetric quantum mechanics. Then we demonstrate that the supersymmetry…
6d Dirac fermion on a rectangle; scrutinizing boundary conditions, mode functions and spectrum
Yukihiro Fujimoto, Kouhei Hasegawa, Kenji Nishiwaki +2
We classify possible boundary conditions of a 6d Dirac fermion on a rectangle under the requirement that the 4d Lorentz structure is maintained, and derive the profiles and spe…
Comprehensive Analysis of Yukawa Hierarchies on with Magnetic Fluxes
Yukihiro Fujimoto, Tatsuo Kobayashi, Kenji Nishiwaki +2
Based on the result of classification in our previous work, we exhaustively investigate Yukawa sector of model on magnetized orbifolds , , $T^{2}/Z…
LHC constraints and prospects for scalar leptoquark explaining the anomaly
Béranger Dumont, Kenji Nishiwaki, Ryoutaro Watanabe
Recently, deviations in flavor observables of B -> D(*) tau nu have been shown between the predictions in the Standard Model and the experimental results reported by BaBar, Belle,…
Double Froggatt--Nielsen Mechanism
Kenji Nishiwaki, Yusuke Shimizu, Yoshiyuki Tatsuta
We present a doubly parametric extension of the standard Froggatt--Nielsen (FN) mechanism. As is well known, mass matrices of the up- and down-type quark sectors and the charged le…
Active Dirac Neutrinos via Doublets in 5d
Yukihiro Fujimoto, K. Hasegawa, Tomoaki Nagasawa +3
We propose a new mechanism to generate minuscule active neutrino masses in a five-dimensional~(5d) spacetime of an interval without introducing singlet neutrinos. Under a…
LHC 750 GeV Diphoton excess in a radiative seesaw model
Shinya Kanemura, Kenji Nishiwaki, Hiroshi Okada +3
We investigate a possibility for explaining the recently announced 750\,GeV diphoton excess by the ATLAS and the CMS experiments at the CERN LHC in a model with multiple doubly cha…
Leptoquark explanation of and muon
Seungwon Baek, Kenji Nishiwaki
We consider lepton flavor violating Higgs decay, specifically , in a leptoquark model. We introduce two scalar leptoquarks with the …
Three Loop Neutrino Model with Isolated
Kenji Nishiwaki, Hiroshi Okada, Yuta Orikasa
We propose a three loop radiative neutrino mass scenario with an isolated doubly charged singlet scalar without couplings to the charged leptons, while two other singl…