W/Z boson decays:
* W-boson decay channels. PYTHIA 6
* ------------------------------------------------------
* 190= d~ u, 191= d~ c, 192= d~ t, 193= d~ t4,
* 194= s~ u, 195= s~ c, 196= s~ t, 197= s~ t4,
* 198= b~ u, 199= b~ c, 200= b~ t, 201= b~ t4,
* 202= b4~ u, 203= b4~ c, 204= b4~ t, 205= b4~ t4,
* 206= e+ nu, 207= mu+ nu, 208= tau+ nu, 209= L nu
* WARNING: in TopRex only (-1,0,1,2,3) values can be used !
* ------------------------------------------------------
* Z-boson decay channels. PYTHIA 6
* -------------------------------------------------------------------
* 174= d d~, 175= u u~, 176= s s~, 177= c c~,
* 178= b b~, 179= t t~, 180= b4 b4~, 181= t4 t4~,
* 182= e- e+, 183= nue nue~, 184= mu- mu+, 185= numu numu~'
* 186= tau- tau+, 187= nu_tau nu_tau~, 188= L- L+, 189= NU_L NU_L~
* -------------------------------------------------------------------