Two-loop improved predictions for $M_W$ and ${\sin }^2{\theta }_{eff}$ in Two-Higgs-Doublet Models

Abstract

We present the currently most precise predictions for the $W$-boson mass and the leptonic effective mixing angle ${\sin }^2{\theta }_{\text{eff}}$ in the aligned Two-Higgs-Doublet Model. The evaluation includes the full one-loop result, all known higher-order corrections of the Standard Model, and the non-standard two-loop contributions that increase with mass splittings between charged and neutral THDM Higgs bosons. They depend on $\tan \beta$ and the soft $Z_2$-symmetry breakingparameter $m_{12}^2$ of the scalar potential, in addition to the non-standard boson masses. Whenever the one-loop corrections become large, the two-loop contributions yield substantial modifications of the predictions, which is of particular importance for the $W$ mass where large mass shifts are required to reach the recently published final resultof the CDF collaboration. Numerical results are shown for the dependence on the various non-standard parameters and in comparison with experimental data.

Comments: 26 pages, 5 figures