The CDF W-mass, muon g-2, and dark matter in a U(1)Lμ-Lτ model with vector-like leptons

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 (E1, E2, N), a new gauge boson Z' , 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(E1) = m(E2) = 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 m(E1) (s(L)) and m(E2) (s(R)), 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 -> Z' Z' , SS for m(Z')(m(S)) < mX(I) and (ii) the co-annihilation processes for min(m(E1,) m(E2), m(N), m(XR)) close to m(XI). Finally, we use the direct searches for 2l + 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.

Automated summary

We study the CDF W-mass, muon g-2, and dark matter observables in a local U(1)L-mu-L-tau model. We find that the CDF W-mass is related to the mixing parameter of left (right)-handed fields of vector-like leptons and favors a large mass splitting between them when the differences between mixing parameters become small. The correct dark matter relic density is mainly obtained in two scenarios, one involving the annihilation of X-I X-I into Z' Z' and SS, and the other involving co-annihilation processes.