Charged Higgs sector

MSEL = 23
ISUB =

143	$\mathrm{f}_i \overline{\mathrm{f}}_j \to \H ^+$
161	$\mathrm{f}_i \mathrm{g}\to \mathrm{f}_k \H ^+$

A charged Higgs doublet, $\H ^{\pm}$, is included in the program. This doublet may be the one predicted in the MSSM scenario, see section , or in any other scenario. The $\tan\beta$ parameter, which is relevant also for charged Higgs couplings, is set via PARU(141) or, if Susy is switched on, via RMSS(5).

The basic subprocess for charged Higgs production in hadron colliders is ISUB = 143. However, this process is dominated by $\t\overline{\mathrm{b}}\to \H ^+$, and so depends on the choice of $\t$ parton distribution, if at all present. A better representation is provided by subprocess 161, $\mathrm{f}\mathrm{g}\to \mathrm{f}' \H ^+$; i.e. actually $\overline{\mathrm{b}}\mathrm{g}\to \overline{\mathrm{t}}\H ^+$. It is therefore recommended to use 161 and not 143; to use both would be double-counting.

Pair production of Higgs states may be a relevant source, see section  below.

A major potential source of charged Higgs production is top decay. It is possible to switch on the decay channel $\t\to \b\H ^+$. Top will then decay to $\H ^+$ a fraction of the time, whichever way it is produced. The branching ratio is automatically calculated, based on the $\tan\beta$ value and masses. It is possible to only have the $\H ^+$ decay mode switched on, in which case the cross section is reduced accordingly.