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Feng-Yan Niu

Publications and source records attributed to Feng-Yan Niu.

2 recordsLinked to original sources

Lepton-flavor violation and muon $(g-2)$ in the flavor-dependent $U(1)_F$ model

Lepton flavor violation (LFV) processes are forbidden in the standard model (SM), hence the observation of LFV transitions would represent a clear signal of new physics beyond the SM. In this work, we investigate the muon anomalous magnetic dipole moments (MDM) and LFV processes $l_{j}^{-}\to l_{i}^{-}\gamma $ and $l_{j}^{-}\to l_{i}^{-}l_{i}^{-}l_{i}^{+}$ in the extension of the SM with $U(1)_F$ local gauge symmetry (FDM). The muon anomalous MDM is one of the most precisely measured quantities in particle physics, which can be used to constrain the contributions from new couplings in the FDM. The newly incorporated $U(1)_F$ charges are correlated with the flavor properties of fermions, hence the newly added Yukawa couplings make contributions to these LFV processes. Considering the latest experimental constraints on the muon anomalous MDM, the new interactions in the FDM can make significant contributions to the LFV processes $l_{j}^{-}\to l_{i}^{-}\gamma $ and $l_{j}^{-}\to l_{i}^{-}l_{i}^{-}l_{i}^{+}$, the predicted branching ratios can well reach the future experimental sensitivity.

hep-ph

The origin of the 95 GeV excess in the flavor-dependent U(1)X model

This study investigates the excesses observed in the CMS diphoton and ditau data around 95 GeV within the framework of the flavor-dependent U(1)X model. The model introduces a singlet scalar to explain the nonzero neutrino masses. This newly introduced Higgs interacts directly with the quark sector, motivated by the aim to explain the flavor numbers of the fermion sector. Additionally, it undergoes mixing with the SM-like Higgs boson. The study suggests that designating this singlet Higgs state in this model as the lightest Higgs boson holds great potential for explaining the excesses around 95 GeV. In the calculations, we maintained the masses of the lightest and next-to-lightest Higgs bosons at around 95 GeV and 125 GeV respectively. It was found that the theoretical predictions on the signal strengthes μ(h95)_γγ, μ(h95)_ττ in the flavor-dependent U(1)X model can be fitted well to the excesses observed at CMS.

hep-ph