Bounds on the Simplest Little Higgs Model Mass Spectrum Through Z Leptonic Decay

Dias, Alex G.; Pires, C. A. de S.; da Silva, P. S. Rodrigues

Bounds on the Simplest Little Higgs Model Mass Spectrum Through Z Leptonic Decay

Authors

Dias, Alex G.

Pires, C. A. de S.

da Silva, P. S. Rodrigues

Description

We derive the leptonic neutral current in the simplest little Higgs model and compute the contribution of the model to the decay width $Z \to e^+e^-$. Using the precision electroweak data we obtain a strong lower bound $f\geq 5.6$ TeV at 95% C.L. on the characteristic energy scale of the model. It results in a lower bound for the new gauge bosons $W^{\prime\pm}$ and $Z^{\prime}$ as being $M_{W^{\prime\pm}}\geq 2.6$ TeV and $M_{Z^{\prime}}\geq 3.1$ TeV, respectively. We also present the allowed values of the $k=f_1/f_2$ which is the parameter relating the two vacuum expectation values of the scalar triplets in the model, and the $μ$ parameter of a quadratic term, involving the triplets, necessary to provide an acceptable mass range for the standard Higgs boson.
New references added, 13 pages. Version to be published