| 67 | | 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). 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 B-L-breaking vev and the Z-boson are INTERNAL parameters, evaluated as a function of the input parameters (g1p, 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 II constraints to obtain a Z mass compatible with the LEP II measurement, within errors. |
| | 67 | The choice of benchmark model within the class is done by choosing the free parameters below. |
| | 68 | |
| | 69 | Free parameters |
| | 70 | * Scalar sector |
| | 71 | * Higgs mixing angle, sa |
| | 72 | * The mass of the Higgs, mh1 and mh2, where mh1 is usually the mass of the SM model Higgs. |
| | 73 | * Gauge boson sector |
| | 74 | * The Z' boson mass, mzp |
| | 75 | * The coupling constant of B-L group, g1p |
| | 76 | * Neutrino sector |
| | 77 | * The heavy neutrino mass, mnh1, mnh2 and mnh3 |
| | 78 | * The light neutrino mass, mnl1, mnl2 and mnl3 |
| | 79 | * The neutrino mixing matrix are internal parameter set by Type-I seesaw, please read http://arxiv.org/abs/arXiv:0812.4313. |
| | 80 | * Please set the decay width of the heavy neutrino, two Higgs and Z' to auto (in MadGraph5 param_card.dat) |
