Higgs Processes

This page contains Higgs production within and beyond the Standard Model. It is at a very early stage.

Standard-Model Higgs

flag  SMHiggs:all   (default = off)
Common switch for the group of Higgs production within the Standard Model.

flag  SMHiggs:ffbar2H   (default = off)
Scattering f fbar -> H^0, where f sums over available flavours except top. Code 801.

flag  SMHiggs:gg2H   (default = off)
Scattering g g -> H^0. Code 802.

flag  SMHiggs:gmgm2H   (default = off)
Scattering gamma gamma -> H^0. Code 803.

flag  SMHiggs:ffbar2HZ   (default = off)
Scattering f fbar -> H^0 Z^0. Code 804.

flag  SMHiggs:ffbar2HW   (default = off)
Scattering f fbar -> H^0 W^+-. Code 805.

flag  SMHiggs:qg2Hq   (default = off)
Scattering q g -> H^0 q. This process gives first-order corrections to the f fbar -> H^0 one above (for f = q ), so both cannot be used simultaneously without unphysical doublecounting. The current one should only be used to study the high-pT tail, while f g -> H^0 f should be used for inclusive production. Therefore this process is not switched on by the SMHiggs:all flag. Code 806.

Parameters for Higgs production and decay

flag  ResonanceH::linearWidthWWZZ   (default = on)
The partial width of a Higgs particle to a pair of gauge bosons, W^+ W^- or Z^0 Z^0, depends cubically on the Higgs mass. When selecting the Higgs according to a Breit-Wigner, so that the actual mass mHat does not agree with the nominal m_Higgs one, an ambiguity arises which of the two to use [Sey95]. The default is to use a linear dependence on mHat, i.e. a width proportional to m_Higgs^2 * mHat, while off gives a mHat^3 dependence. This does not affect the width to fermions, which only depends on mHat.

mode  SMHiggs:parity   (default = 1; minimum = 0; maximum = 3)
possibility to modify angular decay correlations in Higgs decay to Z^0 Z^0 or W^+ W^- to four fermions. Currently it does not affect the partial width of the channels.
option 0 : isotropic decays.
option 1 : assuming the Higgs is a pure scalar (CP-even), as in the Standard Model.
option 2 : assuming the Higgs is a pure pseudoscalar (CP-odd).
option 3 : assuming the Higgs is a mixture of the two, including the CP-violating interference term. The parameter eta, see below, sets the strength of the CP-odd admixture, with the interference term being proportional to eta and the CP-odd one to eta^2.

parm  SMHiggs:etaParity   (default = 0.)
The eta value of CP-violation in the SMHiggs:parity = 2 option.