The CDF W-mass, muon g-2, and dark matter in a $U(1{)}_{L_{\mu }-L_{\tau }}$ model with vector-like leptons

Abstract

We study the CDF $W$-mass, muon $g-2$, and dark matter observables in a local $U(1{)}_{L_{\mu }-L_{\tau }}$ model in which the new particles include three vector-like leptons ($E_1,E_2,N$), a new gauge boson $Z^{\prime }$, a scalar $S$ (breaking $U(1{)}_{L_{\mu }-L_{\tau }}$), a scalar dark matter $X_I$ and its partner $X_R$. We find that the CDF $W$-mass disfavors $m_{E_1}=m_{E_2}=m_N$ or $s_L=s_R=0$ where $s_{L(R)}$ is mixing parameter of left (right)-handed fields of vector-like leptons. A large mass splitting between $E_1$ and $E_2$ is favored when the differences between $s_L$ and $s_R$ becomes small. The muon $g-2$ anomaly can be simultaneously explained for appropriate difference between $s_L$ $(m_{E_1})$ and $s_R$ $(m_{E_2})$, and some regions are excluded by the diphoton signal data of the 125 GeV Higgs. Combined with the CDF $W$-mass, muon $g-2$ anomaly and other relevant constraints, the correct dark matter relic density is mainly obtained in two different scenarios: (i) $X_I{X}_I\to Z^{\prime }{Z}^{\prime },SS$ for $m_{Z^{\prime }}(m_S)<m_{X_I}$ and (ii) the co-annihilation processes for $min(m_{E_1},m_{E_2},m_N,m_{X_R})$ closed to $m_{X_I}$. Finally, we use the direct searches for $2\ell +E_T^{miss}$ event at the LHC to constrain the model, and show the allowed mass ranges of the vector-like leptons and dark matter.

Comments: 18 pages, 4 figures, 1 tables