| | 46 | The choice of benchmark model within the class is done by selecting the appropriate relation between the new gauge couplings. "g1p" is the gauge coupling directly connected to the U(1)_{B-L} group (also present in the minimal B-L model files), "gt" is the mixing parameter. Because of the limited number of degrees of freedom, the Z' mass has been chosen as the last free parameter, adjustable by the user. Therefore, the mixing Z-Z' angle, the B-L-breaking vev and the Z-boson are INTERNAL parameters, evaluated as a function of the input parameters (g1p, gt, MZp). Henceforth, it's up to the user to choose values for the independent parameter complying to experimental constraints to ensure not to spoil in particular the Z mass. Per given benchmark model, it is sufficient to choose a Zp mass allowed by the LEP constraints to obtain a Z mass compatible with the LEP measurement, within errors. |
