Leptonic di-flavor and di-number violation processes at high energyμ^(±)μ^(±)colliders

The leptonic di-flavor violation (LFV) processes μ^(±)μ^(±)→e^(±)e^(±) and μ^(±)μ^(±)→τ^(±)τ^(±) and leptonic di-number violation (LNV) processes μ^(±)μ^(±)→W_(i)^(±)W_(j)^(±) (i,j=1,2) at same-sign high energy μ^(±)μ^(±) colliders are studied. The new physics (NP) factors that may play roles in these processes are highlighted by cataloging them into three types. Taking into account the experimental constraints, the processes at μ^(±)μ^(±) colliders are computed, and the results are presented properly. The results lead to the conclusion that observing the NP factors through the LFV and LNV processes at TeV-energy μ^(±)μ^(±) colliders has significant advantages that cannot be achieved elsewhere. Therefore, once the techniques for muon acceleration and collision are developed successfully, the option of building same-sign high energy muon colliders should be seriously considered.

W boson mass in NP models with an extra U(1)gauge group

The precise measurement of the W boson mass is closely related to the contributions of new physics(NP),which can significantly constrain the parameter space of NP models,particularly those with an additional U(1)local gauge group.The inclusion of a new Z'gauge boson and gauge couplings in these models can contribute to the oblique parameters S,T,and U and the W boson mass at tree level.Considering the effects of kinetic mixing,in this study,we calculate and analyze the oblique parameters S,T,and U and the W boson mass in such NP models.We find that the kinetic mixing effects can make significant contributions to the W boson mass,and these contributions can be eliminated by redefining the gauge boson fields by removing neutral currents with charged leptons if the leptonic Yukawa couplings are invariant under the extra U(1)local gauge group,even with nonzero kinetic mixing effects.

Nuclear 0ν2βdecays in B-L symmetric SUSY model and in TeV scale left–right symmetric model

In this paper,we take the B-L supersymmetric standard model(B-LSSM)and TeV scale left–right symmetric model(LRSM)as two representations of the two kinds of new physics models to study the nuclear neutrinoless double beta decays(0ν2β)so as to see the senses onto these two kinds of models when the decays are taken into account additionally.Within the parameter spaces allowed by all the existing experimental data,the decay half-life of the nucleus^(76)Ge and^(136)Xe,T_(12)^(0ν)(^(76)Ge,^(136)Xe),is precisely calculated and the results are presented properly.Based on the numerical results,we conclude that there is greater room for LRSM type models than for B-LSSM type models in foreseeable future experimental observations on the decays.

Muon anomalous Muon anomalous Muon anomalous magnetic dipole moment in theμνSSM

Recently,the Muon g-2 experiment at Fermilab measured the muon anomalous magnetic dipole moment(MDM),aμ=(gμ-2)/2,and reported that the new experimental average increases the difference between the experiment and the standard model(SM)prediction to 4.2σ.In this work,we reanalyze the muon anomalous MDM at the two-loop level in theμfrom theνSupersymmetric Standard Model(μνSSM)combined with the updated experimental average.TheμνSSM can explain the current difference between the experimental measurement and the SM theoretical prediction for the muon anomalous MDM,constrained by the 125 GeV Higgs boson mass and decays,the rare decayˉB→Xsγ,and so on.We also investigate the anomalous MDM of the electron and tau lepton,ae=(ge-2)/2 and aτ=(gτ-2)/2,at the two-loop level in theμνSSM.In addition,the decaying of the 125 GeV Higgs boson into a pair of charged leptons in theμνSSM is analyzed.