## Improved Constraints on Z' Bosons from Electroweak Precision Data

Erler, Jens
Langacker, Paul
Munir, Shoaib
Rojas, Eduardo
##### Description
We analyze various models with an extra U(1) gauge symmetry in addition to the Standard Model (SM) gauge group at low energies, and impose limits on the mass of the neutral Z' boson, M_Z', predicted in all such models, and on the Z-Z' mixing angle, theta_ZZ'. The precision electroweak data strongly constrain theta_ZZ' to very small values and for most models we find lower limits on M_Z' of order 1 TeV. In one case we obtain a somewhat better fit than in the SM (although this is only marginally statistically significant) and here we find a weak upper limit at the 90% C.L.
Comment: 18 pages, 10 figures, final version as it will appear in Journal (JHEP)
##### Keywords
High Energy Physics - Phenomenology, High Energy Physics - Experiment