A5030688257- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- Dark Matter and Cosmic Phenomena
- Black Holes and Theoretical Physics
- Neutrino Physics Research
- Cosmology and Gravitation Theories
- High-Energy Particle Collisions Research
- Computational Physics and Python Applications
- Particle Detector Development and Performance
- Particle Accelerators and Free-Electron Lasers
- Distributed and Parallel Computing Systems
- Astrophysics and Cosmic Phenomena
- International Science and Diplomacy
- Rural development and sustainability
- demographic modeling and climate adaptation
- Atomic and Subatomic Physics Research
- Quantum Electrodynamics and Casimir Effect
- Advanced Thermodynamics and Statistical Mechanics
- Law, logistics, and international trade
- Noncommutative and Quantum Gravity Theories
- Quantum Mechanics and Applications
- Nonlinear Waves and Solitons
- Advanced Algebra and Geometry
Osaka University
2019-2025
National Center for Theoretical Sciences
2022
National Taiwan University
2022
University of Florence
2017-2020
University of Southampton
2011-2020
Istituto Nazionale di Fisica Nucleare, Sezione di Firenze
2017-2020
Rutherford Appleton Laboratory
2020
Seikei University
2018-2019
National Central University
2012-2015
University of Toyama
2009-2012
Possible models of Yukawa interaction are discussed in the two Higgs doublet model (THDM) under discrete symmetry imposed to avoid flavor changing neutral current at leading order. It is known that there four types such corresponding possible different assignment charges for on quarks and leptons. We first examine decay properties bosons each type model, summarize constraints from experimental data. then shed light differences among these collider phenomenology. In particular, we mainly...
The goal of this report is to summarize the current situation and discuss possible search strategies for charged scalars, in non-supersymmetric extensions Standard Model at LHC. Such scalars appear Multi-Higgs-Doublet models (MHDM), particular popular Two-Higgs-Doublet model (2HDM), allowing additional neutral Higgs bosons. These have attractive property that electroweak precision observables are automatically agreement with tree level. For most version framework, Model~II, a discovery boson...
We study radiative corrections to the electroweak parameters in Higgs model with Y=1 triplet field, which is introduced scenario of generating neutrino masses based on so-called type II seesaw mechanism. In this model, rho parameter deviates from unity at tree level. Consequently, sector described by four input such as $\alpha_{\text{em}}$, $G_F$, $m_Z$ and $\sin^2\theta_W$. calculate one loop contribution W boson mass well order clarify possible spectrum extra bosons under constraint...
After the discovery of standard-model-like Higgs boson at LHC, structure sector remains unknown. We discuss how it can be determined by combination direct and indirect searches for additional bosons future collider experiments. First all, we evaluate expected excluded regions mass neutral from LHC with 14 TeV collision energy in two doublet models a softly-broken $Z_2$ symmetry. Second, precision measurements couplings experiments used search extended sectors if measured coupling constant...
We investigate unitarity bounds in the most general two Higgs doublet model without a discrete Z2 symmetry nor CP conservation. S-wave amplitudes for two-body elastic scatterings of Nambu–Goldstone bosons and physical are calculated at high energies all possible initial final states (14 neutral, 8 singly-charged 3 doubly-charged states). obtain analytic formulae block-diagonalized scattering matrix by classification body using conserved quantum numbers energies. Imposing condition...
We calculate radiative corrections to a full set of coupling constants for the 125 GeV Higgs boson at one-loop level in two doublet models with four types Yukawa interaction under softly-broken discrete $Z_2$ symmetry. The renormalization calculations are performed on-shell scheme, which gauge dependence mixing parameter appears previous calculation is consistently avoided. first show details our renormalizaton and present complete analytic formulae renormalized couplings. then numerically...
We discuss the Type-X (lepton-specific) two Higgs doublet model as a solution of anomaly muon g − 2. consider various experimental constraints on parameter space such direct searches for extra bosons at LEP II and LHC Run-I, electroweak precision observables, decay B s → μ+μ−, leptonic tau lepton. find that measurement provides most important constraint, which excludes region can explain 2 1σ level. then phenomenology standard model-like boson (h) to probe scenario favored by data collider...
A new report for the measurement of W boson mass has been provided by CDF II experiment. The measured value is given to be $m_W^{\text{CDF II}} = 80.4335 \pm 0.0094$ GeV which shows $7\sigma$ deviation from standard model prediction, while other groups high energy experiments, e.g., ATLAS and D0 II, show consistent results with latter. Assuming that at correct, we discuss possibility explain anomaly in Higgs triplet model. We find can explained under constraints electroweak rho parameter,...
In general, there can be mass differences among scalar bosons of the Higgs triplet field with hypercharge $Y=1$. model, when vacuum expectation value ${v}_{\ensuremath{\Delta}}$ is much smaller than that $v$ ($\ensuremath{\simeq}246\text{ }\text{ }\mathrm{GeV}$) doublet as required by electroweak precision data, a characteristic spectrum...
We calculate a full set of one-loop corrections to the Higgs boson coupling constants as well electroweak parameters. compute decay rate standard model (SM)-like ($h$) into diphoton. Renormalized couplings with weak gauge bosons $hVV$ ($V=W$ and $Z$) trilinear $hhh$ are also calculated at level in on-shell scheme. Magnitudes deviations these quantities evaluated parameter regions where unitarity vacuum stability bounds satisfied predicted W mass is consistent data. find that there strong...
We calculate renormalized Higgs boson couplings with gauge bosons and fermions at the one-loop level in model an additional isospin singlet real scalar field. These coupling constants can deviate from predictions standard due to tree-level mixing effects contributions of extra neutral boson. investigate how they be significant under theoretical constraints perturbative unitarity vacuum stability also condition avoiding wrong vacuum. Furthermore, comparing Type I two doublet model, we...
We propose a radiative seesaw model with an inert triplet scalar field in which Majorana neutrino masses are generated at the two loop level. There fermionic or bosonic dark matter candidates model. find that each candidate can satisfy WMAP data when its mass is taken to be around half of standard like Higgs boson. also discuss phenomenology bosons, especially focusing on doubly-charged bosons Large Hadron Collider parameter regions constrained by electroweak precision and data. study how we...
We investigate predictions on the triple Higgs boson couplings with radiative corrections in model an additional real singlet scalar field. In this model, second physical state ($H$) appears addition to ($h$) mass 125 GeV. The $hhh$ vertex is calculated at one-loop level, and its possible deviation from standard evaluated under various theoretical constraints. decay rate of $H \to hh$ also computed level. take into account bound precise measurement $W$ mass, which gives upper limit mixing...
A direct search for doubly-charged Higgs bosons $H^{\pm\pm}$ is one of the most important probe in Triplet Model, which motivated by generation mechanisms tiny neutrino masses. There are two major decay modes $H^{\pm\pm}$; i.e., same-sign dilepton $H^{\pm\pm}\to\ell^\pm\ell^\pm$ and diboson $H^{\pm\pm}\to W^{\pm(*)}W^{\pm(*)}$. For case where former mode dominant, lower limit on mass has been set at about 400 GeV ATLAS CMS Collaborations. On other hand, latter no dedicated performed past. By...
We discuss a possible explanation of the recently observed diphoton excess at around 750 GeV as seen by ATLAS and CMS experiments Large Hadron Collider. calculate cross section signature in two-Higgs-doublet models with addition real isospin scalar multiplet without vacuum expectation value, where neutral component such representation can be dark matter candidate. find that branching fraction an additional $CP$-even Higgs boson $H$ from doublet fields into mode significantly enhanced, up to...
We propose simple models with a flavor-dependent global $U(1)_\ell$ and discrete $\mathbb{Z}_2$ symmetries to explain the anomalies in measured anomalous magnetic dipole moments of muon electron, $(g-2)_{\mu,e}$, while simultaneously accommodating dark matter candidate. These new are introduced not only avoid dangerous lepton flavor-violating decays charged leptons, but also ensure stability matter. Our can realize opposite-sign contributions electron $g-2$ via one-loop diagrams involving...
We study coupling constants of the standard model-like Higgs boson with gauge bosons $hZZ$ and $hWW$ fermions $hf\overline{f}$ in general sector which contains higher isospin representations arbitrary hypercharge. In sectors exotic representations, can be larger than those model. calculate deviations couplings from model values a real or complex triplet field, Georgi-Machacek septet scalar field. also event rates $h\ensuremath{\rightarrow}Z{Z}^{*}$, $h\ensuremath{\rightarrow}W{W}^{*}$,...
The decays of a Higgs boson to the $\gamma\gamma$ and $Z\gamma$ final states are purely quantum mechanical phenomena that closely related each other. We study effects an extended sector on decay rates two modes. propose simultaneous determination them $ZZ$ mode is useful way see whether recently observed by LHC experiments standard model type or could be member larger sector.
The same-sign diboson process $pp\ensuremath{\rightarrow}{W}^{\ifmmode\pm\else\textpm\fi{}}{W}^{\ifmmode\pm\else\textpm\fi{}}jj$ has been measured at the LHC using leptonic decay channels of $W$ bosons, with production cross sections two fiducial regions reported to be consistent Standard Model expectations within $1\ensuremath{\sigma}$. These results constrain new physics models a modified ${W}^{+}{W}^{+}{W}^{\ensuremath{-}}{W}^{\ensuremath{-}}$ vertex. We consider in particular...
We comprehensively evaluate renormalized Higgs boson couplings at one-loop level in nonminimal models such as the singlet model (HSM) and four types of two doublet (THDMs) with a softly broken ${Z}_{2}$ symmetry. The renormalization calculation is performed on-shell scheme improved by using pinch technique to eliminate gauge dependence couplings. first review for scalar two-point functions standard (SM), HSM THDMs. then discuss difference results between ordinal one appearing mixing...
We propose a two-loop induced Zee-Babu-type neutrino mass model at the TeV scale. Although there is no dark matter candidate in original Zee-Babu model, our can include by introducing an unbroken discrete ${Z}_{2}$ symmetry. The discrepancy between experimental value of muon anomalous magnetic moment (muon $g\ensuremath{-}2$) and its prediction standard be explained contributions from additional vectorlike charged leptons which are necessary to give nonzero masses. slightly above 300 GeV...
In this letter, we study the latest bound on mass of doubly charged Higgs bosons, |$H^{\pm \pm }$|, assuming that they dominantly decay into a diboson. The new is obtained by comparing inclusive searches ATLAS Collaboration [ATLAS Collaboration, J. High Energy Phys. 1503, 041 (2015)] for events with same-sign dilepton using 20.3 fb|$^{-1}$| data at Large Hadron Collider 8 TeV run theoretical prediction based triplet model next-to-leading order QCD corrections. We find lower }$| about 84 GeV.