Kei Yagyu

collaborators

4 papers

hep-ph2025

Are 2HDMs with a gauged $U (1)$ symmetry alive?

Yuanchao Lou, Takaaki Nomura, Xinran Xu +1

We investigate the phenomenology of 2 Higgs doublet models (2HDMs) with a new $U (1)$ gauge symmetry, $U (1)_{X}$ , by which flavor changing neutral currents are forbidden at tree level…

hep-ph2025

Lepton number violation from Higgs/ $Z$ decays into a pair of right-handed neutrinos

Arindam Das, Takaaki Nomura, Kei Yagyu

We explore signatures of Lepton Number Violation (LNV) from decays of the discovered Higgs ( $h$ ) and Z bosons into a pair of Right-Handed Neutrinos (RHNs). Due to the Majorana natu…

hep-ph2025

Multi-Lepton Jets from Quadruple $Z^{'}$ via the Higgs Decay at LHC

Jinmian Li, Takaaki Nomura, Kei Yagyu

We investigate multi-lepton jet events from the decay of the 125 GeV Higgs boson ( $h$ ) into quadruple new gauge bosons $(Z^{'})$ at the LHC. Such an exotic decay is realized via the p…

hep-ph2024

Triple $Z^{'}$ signatures at $Z$ factories

Takaaki Nomura, Kei Yagyu

We discuss triple $Z^{'}$ boson signatures via the decay chain of $Z \to Z^{'} I ¨ \to Z^{'} Z^{'} Z^{'}$ , with a new light scalar $I ¨ $ , at future Z factories such as CEPC and FCC-ee. These new bos…

Are 2HDMs with a gauged U(1) symmetry alive?

Lepton number violation from Higgs/Z decays into a pair of right-handed neutrinos

Multi-Lepton Jets from Quadruple Z′ via the Higgs Decay at LHC

Triple Z′ signatures at Z factories

Are 2HDMs with a gauged $U (1)$ symmetry alive?

Lepton number violation from Higgs/ $Z$ decays into a pair of right-handed neutrinos

Multi-Lepton Jets from Quadruple $Z^{'}$ via the Higgs Decay at LHC

Triple $Z^{'}$ signatures at $Z$ factories