Higgs Processes

This page documents Higgs production within and beyond the Standard Model (SM and BSM for short). This includes several different processes and, for the BSM scenarios, a large set of parameters that would only be fixed within a more specific framework such as MSSM. Some choices can be made irrespective of the particular model:

flag  Higgs:cubicWidth   (default = off)
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 on gives a mHat^3 dependence. This does not affect the widths to fermions, which only depend linearly on mHat. This flag is used both for SM and BSM Higgs bosons.

flag  Higgs:runningLoopMass   (default = on)
The partial width of a Higgs particle to a pair of gluons or photons, or a gamma Z^0 pair, proceeds in part through quark loops, mainly b and t. There is some ambiguity what kind of masses to use. Default is running MSbar ones, but alternatively fixed pole masses are allowed (as was standard in PYTHIA 6), which typically gives a noticeably higher cross section for these channels. (For a decay to a pair of fermions, such as top, the running mass is used for couplings and the fixed one for phase space.)

flag  Higgs:clipWings   (default = on)
The Breit-Wigner shape of a Higgs is nontrivial, owing to the rapid width variation with the mass of a Higgs. This implies that a Higgs of low nominal mass may still acquire a non-negligible high-end tail. The validity of the calculation may be questioned in these wings. With this option on, the Higgs:wingsFac value is used to cut away the wings.
Warning: with this option on, the allowed mass range is shrunk, but never widened. This can lead to inconsistencies if a run consists of several subruns with different Higgs masses. The id:mMin and id:mMax values should therefore be reset (e.g. to the defaults 50. and 0.) when id:m0 is changed.

parm  Higgs:wingsFac   (default = 50.; minimum = 0.)
With Higgs:clipWings on, all Higgs masses which deviate from the nominal one by more than Higgs:wingsFac times the nominal width are forbidden. This is achieved by setting the mMin and mMax values of the Higgs states at initialization. These changes never allow a wider range than already set by the user, alternatively by the current default values, see warning above.

One setting is specific to the Standard Model:

flag  HiggsSM:NLOWidths   (default = on)
The partial width of the SM Higgs particle are multiplied by the respective factors needed to bring the LO widths encoded in PYTHIA to the NLO ones recommended by the LHCXSWG. The multiplicative factors have been derived for a 125 GeV Higgs, but should apply for a reasonable mass range around that value.

Standard-Model Higgs, basic processes

This section provides the standard set of processes that can be run together to provide a reasonably complete overview of possible production channels for a single SM Higgs. The main parameter is the choice of Higgs mass, which can be set in the normal ParticleData database; thereafter the properties within the SM are essentially fixed.

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

flag  HiggsSM:ffbar2H   (default = off)
Scattering f fbar → H^0, where f sums over available flavours except top. Related to the mass-dependent Higgs point coupling to fermions, so at hadron colliders the bottom contribution will dominate. Code 901.

flag  HiggsSM:gg2H   (default = off)
Scattering g g → H^0 via loop contributions primarily from top. Code 902.

flag  HiggsSM:gmgm2H   (default = off)
Scattering gamma gamma → H^0 via loop contributions primarily from top and W. Code 903.

flag  HiggsSM:ffbar2HZ   (default = off)
Scattering f fbar → H^0 Z^0 via s-channel Z^0 exchange. Code 904.

flag  HiggsSM:ffbar2HW   (default = off)
Scattering f fbar → H^0 W^+- via s-channel W^+- exchange. Code 905.

flag  HiggsSM:ff2Hff(t:ZZ)   (default = off)
Scattering f f' → H^0 f f' via Z^0 Z^0 fusion. Code 906.

flag  HiggsSM:ff2Hff(t:WW)   (default = off)
Scattering f_1 f_2 → H^0 f_3 f_4 via W^+ W^- fusion. Code 907.

flag  HiggsSM:gg2Httbar   (default = off)
Scattering g g → H^0 t tbar via t tbar fusion (or, alternatively put, Higgs radiation off a top line). Warning: unfortunately this process is rather slow, owing to a lengthy cross-section expression and inefficient phase-space selection. Code 908.

flag  HiggsSM:qqbar2Httbar   (default = off)
Scattering q qbar → H^0 t tbar via t tbar fusion (or, alternatively put, Higgs radiation off a top line). Warning: unfortunately this process is rather slow, owing to a lengthy cross-section expression and inefficient phase-space selection. Code 909.

Standard-Model Higgs, further processes

A number of further production processes has been implemented, that are specializations of some of the above ones to the high-pT region. The sets therefore could not be used simultaneously without unphysical double-counting, as further explained below. They are not switched on by the HiggsSM:all flag, but have to be switched on for each separate process after due consideration.

The first three processes in this section are related to the Higgs point coupling to fermions, and so primarily are of interest for b quarks. It is here useful to begin by reminding that a process like b bbar → H^0 implies that a b/bbar is taken from each incoming hadron, leaving behind its respective antiparticle. The initial-state showers will then add one g → b bbar branching on either side, so that effectively the process becomes g g → H0 b bbar. This would be the same basic process as the g g → H^0 t tbar one used for top. The difference is that (a) no PDF's are defined for top and (b) the shower approach would not be good enough to provide sensible kinematics for the H^0 t tbar subsystem. By contrast, owing to the b being much lighter than the Higgs, multiple gluon emissions must be resummed for b, as is done by PDF's and showers, in order to obtain a sensible description of the total production rate, when the b quarks predominantly are produced at small pT values.

flag  HiggsSM:qg2Hq   (default = off)
Scattering q g → H^0 q. This process gives first-order corrections to the f fbar → H^0 one above, and should only be used to study the high-pT tail, while f fbar → H^0 should be used for inclusive production. Only the dominant c and b contributions are included, and generated separately for technical reasons. Note that another first-order process would be q qbar → H^0 g, which is not explicitly implemented here, but is obtained from showering off the lowest-order process. It does not contain any b at large pT, however, so is less interesting for many applications. Code 911.

flag  HiggsSM:gg2Hbbbar   (default = off)
Scattering g g → H^0 b bbar. This process is yet one order higher of the b bbar → H^0 and b g → H^0 b chain, where now two quarks should be required above some large pT threshold. Warning: unfortunately this process is rather slow, owing to a lengthy cross-section expression and inefficient phase-space selection. Code 912.

flag  HiggsSM:qqbar2Hbbbar   (default = off)
Scattering q qbar → H^0 b bbar via an s-channel gluon, so closely related to the previous one, but typically less important owing to the smaller rate of (anti)quarks relative to gluons. Warning: unfortunately this process is rather slow, owing to a lengthy cross-section expression and inefficient phase-space selection. Code 913.

The second set of processes are predominantly first-order corrections to the g g → H^0 process, again dominated by the top loop. We here only provide the kinematical expressions obtained in the limit that the top quark goes to infinity, but scaled to the finite-top-mass coupling in g g → H^0. (Complete loop expressions are available e.g. in PYTHIA 6.4 but are very lengthy.) This provides a reasonably accurate description for "intermediate" pT values, but fails when the pT scale approaches the top mass.

flag  HiggsSM:gg2Hg(l:t)   (default = off)
Scattering g g → H^0 g via loop contributions primarily from top. Code 914.

flag  HiggsSM:qg2Hq(l:t)   (default = off)
Scattering q g → H^0 q via loop contributions primarily from top. Not to be confused with the HiggsSM:qg2Hq process above, with its direct fermion-to-Higgs coupling. Code 915.

flag  HiggsSM:qqbar2Hg(l:t)   (default = off)
Scattering q qbar → H^0 g via an s-channel gluon and loop contributions primarily from top. Is strictly speaking a "new" process, not directly derived from g g → H^0, and could therefore be included in the standard mix without double-counting, but is numerically negligible. Code 916.

Beyond-the-Standard-Model Higgs, introduction

Further Higgs multiplets arise in a number of scenarios. We here concentrate on the MSSM scenario with two Higgs doublets, but with flexibility enough that also other two-Higgs-doublet scenarios could be represented by a suitable choice of parameters. Conventionally the Higgs states are labeled h^0, H^0, A^0 and H^+-. If the scalar and pseudocalar states mix the resulting states are labeled H_1^0, H_2^0, H_3^0. In process names and parameter explanations both notations will be used, but for settings labels we have adapted the shorthand hybrid notation H1 for h^0(H_1^0), H2 for H^0(H_2^0) and A3 for A^0(H_3^0). (Recall that the Settings database does not distinguish upper- and lowercase characters, so that the user has one thing less to worry about, but here it causes problems with h^0 vs. H^0.) We leave the issue of mass ordering between H^0 and A^0 open, and thereby also that of H_2^0 and H_3^0.

flag  Higgs:useBSM   (default = off)
Master switch to initialize and use the two-Higgs-doublet states. If off, only the above SM Higgs processes can be used, with couplings as predicted in the SM. If on, only the below BSM Higgs processes can be used, with couplings that can be set freely, also found further down on this page.

Beyond-the-Standard-Model Higgs, basic processes

This section provides the standard set of processes that can be run together to provide a reasonably complete overview of possible production channels for a single neutral Higgs state in a two-doublet scenarios such as MSSM. The list of processes for neutral states closely mimics the one found for the SM Higgs. Some of the processes vanish for a pure pseudoscalar A^0, but are kept for flexibility in cases of mixing with the scalar h^0 and H^0 states, or for use in the context of non-MSSM models. This should work well to represent e.g. that a small admixture of the "wrong" parity would allow a process such as q qbar → A^0 Z^0, which otherwise is forbidden. However, note that the loop integrals e.g. for g g → h^0/H^0/A^0 are hardcoded to be for scalars for the former two particles and for a pseudoscalar for the latter one, so absolute rates would not be correctly represented in the case of large scalar/pseudoscalar mixing.

flag  HiggsBSM:all   (default = off)
Common switch for the group of Higgs production beyond the Standard Model, as listed below.

1) h^0(H_1^0) processes

flag  HiggsBSM:allH1   (default = off)
Common switch for the group of h^0(H_1^0) production processes.

flag  HiggsBSM:ffbar2H1   (default = off)
Scattering f fbar → h^0(H_1^0), where f sums over available flavours except top. Code 1001.

flag  HiggsBSM:gg2H1   (default = off)
Scattering g g → h^0(H_1^0) via loop contributions primarily from top. Code 1002.

flag  HiggsBSM:gmgm2H1   (default = off)
Scattering gamma gamma → h^0(H_1^0) via loop contributions primarily from top and W. Code 1003.

flag  HiggsBSM:ffbar2H1Z   (default = off)
Scattering f fbar → h^0(H_1^0) Z^0 via s-channel Z^0 exchange. Code 1004.

flag  HiggsBSM:ffbar2H1W   (default = off)
Scattering f fbar → h^0(H_1^0) W^+- via s-channel W^+- exchange. Code 1005.

flag  HiggsBSM:ff2H1ff(t:ZZ)   (default = off)
Scattering f f' → h^0(H_1^0) f f' via Z^0 Z^0 fusion. Code 1006.

flag  HiggsBSM:ff2H1ff(t:WW)   (default = off)
Scattering f_1 f_2 → h^0(H_1^0) f_3 f_4 via W^+ W^- fusion. Code 1007.

flag  HiggsBSM:gg2H1ttbar   (default = off)
Scattering g g → h^0(H_1^0) t tbar via t tbar fusion (or, alternatively put, Higgs radiation off a top line). Warning: unfortunately this process is rather slow, owing to a lengthy cross-section expression and inefficient phase-space selection. Code 1008.

flag  HiggsBSM:qqbar2H1ttbar   (default = off)
Scattering q qbar → h^0(H_1^0) t tbar via t tbar fusion (or, alternatively put, Higgs radiation off a top line). Warning: unfortunately this process is rather slow, owing to a lengthy cross-section expression and inefficient phase-space selection. Code 1009.

2) H^0(H_2^0) processes

flag  HiggsBSM:allH2   (default = off)
Common switch for the group of H^0(H_2^0) production processes.

flag  HiggsBSM:ffbar2H2   (default = off)
Scattering f fbar → H^0(H_2^0), where f sums over available flavours except top. Code 1021.

flag  HiggsBSM:gg2H2   (default = off)
Scattering g g → H^0(H_2^0) via loop contributions primarily from top. Code 1022.

flag  HiggsBSM:gmgm2H2   (default = off)
Scattering gamma gamma → H^0(H_2^0) via loop contributions primarily from top and W. Code 1023.

flag  HiggsBSM:ffbar2H2Z   (default = off)
Scattering f fbar → H^0(H_2^0) Z^0 via s-channel Z^0 exchange. Code 1024.

flag  HiggsBSM:ffbar2H2W   (default = off)
Scattering f fbar → H^0(H_2^0) W^+- via s-channel W^+- exchange. Code 1025.

flag  HiggsBSM:ff2H2ff(t:ZZ)   (default = off)
Scattering f f' → H^0(H_2^0) f f' via Z^0 Z^0 fusion. Code 1026.

flag  HiggsBSM:ff2H2ff(t:WW)   (default = off)
Scattering f_1 f_2 → H^0(H_2^0) f_3 f_4 via W^+ W^- fusion. Code 1027.

flag  HiggsBSM:gg2H2ttbar   (default = off)
Scattering g g → H^0(H_2^0) t tbar via t tbar fusion (or, alternatively put, Higgs radiation off a top line). Warning: unfortunately this process is rather slow, owing to a lengthy cross-section expression and inefficient phase-space selection. Code 1028.

flag  HiggsBSM:qqbar2H2ttbar   (default = off)
Scattering q qbar → H^0(H_2^0) t tbar via t tbar fusion (or, alternatively put, Higgs radiation off a top line). Warning: unfortunately this process is rather slow, owing to a lengthy cross-section expression and inefficient phase-space selection. Code 1029.

3) A^0(H_3^0) processes

flag  HiggsBSM:allA3   (default = off)
Common switch for the group of A^0(H_3^0) production processes.

flag  HiggsBSM:ffbar2A3   (default = off)
Scattering f fbar → A^0(H_3^0), where f sums over available flavours except top. Code 1041.

flag  HiggsBSM:gg2A3   (default = off)
Scattering g g → A^0(A_3^0) via loop contributions primarily from top. Code 1042.

flag  HiggsBSM:gmgm2A3   (default = off)
Scattering gamma gamma → A^0(A_3^0) via loop contributions primarily from top and W. Code 1043.

flag  HiggsBSM:ffbar2A3Z   (default = off)
Scattering f fbar → A^0(A_3^0) Z^0 via s-channel Z^0 exchange. Code 1044.

flag  HiggsBSM:ffbar2A3W   (default = off)
Scattering f fbar → A^0(A_3^0) W^+- via s-channel W^+- exchange. Code 1045.

flag  HiggsBSM:ff2A3ff(t:ZZ)   (default = off)
Scattering f f' → A^0(A_3^0) f f' via Z^0 Z^0 fusion. Code 1046.

flag  HiggsBSM:ff2A3ff(t:WW)   (default = off)
Scattering f_1 f_2 → A^0(A_3^0) f_3 f_4 via W^+ W^- fusion. Code 1047.

flag  HiggsBSM:gg2A3ttbar   (default = off)
Scattering g g → A^0(A_3^0) t tbar via t tbar fusion (or, alternatively put, Higgs radiation off a top line). Warning: unfortunately this process is rather slow, owing to a lengthy cross-section expression and inefficient phase-space selection. Code 1048.

flag  HiggsBSM:qqbar2A3ttbar   (default = off)
Scattering q qbar → A^0(A_3^0) t tbar via t tbar fusion (or, alternatively put, Higgs radiation off a top line). Warning: unfortunately this process is rather slow, owing to a lengthy cross-section expression and inefficient phase-space selection. Code 1049.

4) H+- processes

flag  HiggsBSM:allH+-   (default = off)
Common switch for the group of H^+- production processes.

flag  HiggsBSM:ffbar2H+-   (default = off)
Scattering f fbar' → H^+-, where f, fbar' sums over available incoming flavours. Since couplings are assumed generation-diagonal, in practice this means c sbar → H^+ and s cbar → H^-. Code 1061.

flag  HiggsBSM:bg2H+-t   (default = off)
Scattering b g → H^+ tbar. At hadron colliders this is the dominant process for single-charged-Higgs production. Code 1062.

5) Higgs-pair processes

flag  HiggsBSM:allHpair   (default = off)
Common switch for the group of Higgs pair-production processes.

flag  HiggsBSM:ffbar2A3H1   (default = off)
Scattering f fbar → A^0(H_3) h^0(H_1). Code 1081.

flag  HiggsBSM:ffbar2A3H2   (default = off)
Scattering f fbar → A^0(H_3) H^0(H_2). Code 1082.

flag  HiggsBSM:ffbar2H+-H1   (default = off)
Scattering f fbar → H^+- h^0(H_1). Code 1083.

flag  HiggsBSM:ffbar2H+-H2   (default = off)
Scattering f fbar → H^+- H^0(H_2). Code 1084.

flag  HiggsBSM:ffbar2H+H-   (default = off)
Scattering f fbar → H+ H-. Code 1085.

Beyond-the-Standard-Model Higgs, further processes

This section mimics the above section on "Standard-Model Higgs, further processes", i.e. it contains higher-order corrections to the processes already listed. The two sets therefore could not be used simultaneously without unphysical double-counting. They are not controlled by any group flag, but have to be switched on for each separate process after due consideration. We refer to the standard-model description for a set of further comments on the processes.

1) h^0(H_1^0) processes

flag  HiggsBSM:qg2H1q   (default = off)
Scattering q g → h^0 q. This process gives first-order corrections to the f fbar → h^0 one above, and should only be used to study the high-pT tail, while f fbar → h^0 should be used for inclusive production. Only the dominant c and b contributions are included, and generated separately for technical reasons. Note that another first-order process would be q qbar → h^0 g, which is not explicitly implemented here, but is obtained from showering off the lowest-order process. It does not contain any b at large pT, however, so is less interesting for many applications. Code 1011.

flag  HiggsBSM:gg2H1bbbar   (default = off)
Scattering g g → h^0 b bbar. This process is yet one order higher of the b bbar → h^0 and b g → h^0 b chain, where now two quarks should be required above some large pT threshold. Warning: unfortunately this process is rather slow, owing to a lengthy cross-section expression and inefficient phase-space selection. Code 1012.

flag  HiggsBSM:qqbar2H1bbbar   (default = off)
Scattering q qbar → h^0 b bbar via an s-channel gluon, so closely related to the previous one, but typically less important owing to the smaller rate of (anti)quarks relative to gluons. Warning: unfortunately this process is rather slow, owing to a lengthy cross-section expression and inefficient phase-space selection. Code 1013.

flag  HiggsBSM:gg2H1g(l:t)   (default = off)
Scattering g g → h^0 g via loop contributions primarily from top. Code 1014.

flag  HiggsBSM:qg2H1q(l:t)   (default = off)
Scattering q g → h^0 q via loop contributions primarily from top. Not to be confused with the HiggsBSM:qg2H1q process above, with its direct fermion-to-Higgs coupling. Code 1015.

flag  HiggsBSM:qqbar2H1g(l:t)   (default = off)
Scattering q qbar → h^0 g via an s-channel gluon and loop contributions primarily from top. Is strictly speaking a "new" process, not directly derived from g g → h^0, and could therefore be included in the standard mix without double-counting, but is numerically negligible. Code 1016.

2) H^0(H_2^0) processes

flag  HiggsBSM:qg2H2q   (default = off)
Scattering q g → H^0 q. This process gives first-order corrections to the f fbar → H^0 one above, and should only be used to study the high-pT tail, while f fbar → H^0 should be used for inclusive production. Only the dominant c and b contributions are included, and generated separately for technical reasons. Note that another first-order process would be q qbar → H^0 g, which is not explicitly implemented here, but is obtained from showering off the lowest-order process. It does not contain any b at large pT, however, so is less interesting for many applications. Code 1031.

flag  HiggsBSM:gg2H2bbbar   (default = off)
Scattering g g → H^0 b bbar. This process is yet one order higher of the b bbar → H^0 and b g → H^0 b chain, where now two quarks should be required above some large pT threshold. Warning: unfortunately this process is rather slow, owing to a lengthy cross-section expression and inefficient phase-space selection. Code 1032.

flag  HiggsBSM:qqbar2H2bbbar   (default = off)
Scattering q qbar → H^0 b bbar via an s-channel gluon, so closely related to the previous one, but typically less important owing to the smaller rate of (anti)quarks relative to gluons. Warning: unfortunately this process is rather slow, owing to a lengthy cross-section expression and inefficient phase-space selection. Code 1033.

flag  HiggsBSM:gg2H2g(l:t)   (default = off)
Scattering g g → H^0 g via loop contributions primarily from top. Code 1034.

flag  HiggsBSM:qg2H2q(l:t)   (default = off)
Scattering q g → H^0 q via loop contributions primarily from top. Not to be confused with the HiggsBSM:qg2H1q process above, with its direct fermion-to-Higgs coupling. Code 1035.

flag  HiggsBSM:qqbar2H2g(l:t)   (default = off)
Scattering q qbar → H^0 g via an s-channel gluon and loop contributions primarily from top. Is strictly speaking a "new" process, not directly derived from g g → H^0, and could therefore be included in the standard mix without double-counting, but is numerically negligible. Code 1036.

3) A^0(H_3^0) processes

flag  HiggsBSM:qg2A3q   (default = off)
Scattering q g → A^0 q. This process gives first-order corrections to the f fbar → A^0 one above, and should only be used to study the high-pT tail, while f fbar → A^0 should be used for inclusive production. Only the dominant c and b contributions are included, and generated separately for technical reasons. Note that another first-order process would be q qbar → A^0 g, which is not explicitly implemented here, but is obtained from showering off the lowest-order process. It does not contain any b at large pT, however, so is less interesting for many applications. Code 1051.

flag  HiggsBSM:gg2A3bbbar   (default = off)
Scattering g g → A^0 b bbar. This process is yet one order higher of the b bbar → A^0 and b g → A^0 b chain, where now two quarks should be required above some large pT threshold. Warning: unfortunately this process is rather slow, owing to a lengthy cross-section expression and inefficient phase-space selection. Code 1052.

flag  HiggsBSM:qqbar2A3bbbar   (default = off)
Scattering q qbar → A^0 b bbar via an s-channel gluon, so closely related to the previous one, but typically less important owing to the smaller rate of (anti)quarks relative to gluons. Warning: unfortunately this process is rather slow, owing to a lengthy cross-section expression and inefficient phase-space selection. Code 1053.

flag  HiggsBSM:gg2A3g(l:t)   (default = off)
Scattering g g → A^0 g via loop contributions primarily from top. Code 1054.

flag  HiggsBSM:qg2A3q(l:t)   (default = off)
Scattering q g → A^0 q via loop contributions primarily from top. Not to be confused with the HiggsBSM:qg2H1q process above, with its direct fermion-to-Higgs coupling. Code 1055.

flag  HiggsBSM:qqbar2A3g(l:t)   (default = off)
Scattering q qbar → A^0 g via an s-channel gluon and loop contributions primarily from top. Is strictly speaking a "new" process, not directly derived from g g → A^0, and could therefore be included in the standard mix without double-counting, but is numerically negligible. Code 1056.

Parameters for Beyond-the-Standard-Model Higgs production and decay

This section offers a big flexibility to set couplings of the various Higgs states to fermions and gauge bosons, and also to each other. The intention is that, for scenarios like MSSM, you should use standard input from the SUSY Les Houches Accord, rather than having to set it all yourself. In other cases, however, the freedom is there for you to use. Kindly note that some of the internal calculations of partial widths from the parameters provided do not include mixing between the scalar and pseudoscalar states.

Masses would be set in the ParticleData database, while couplings are set below. When possible, the couplings of the Higgs states are normalized to the corresponding coupling within the SM. When not, their values within the MSSM are indicated, from which it should be straightforward to understand what to use instead. The exception is some couplings that vanish also in the MSSM, where the normalization has been defined in close analogy with nonvanishing ones. Some parameter names are asymmetric but crossing can always be used, i.e. the coupling for A^0 → H^0 Z^0 obviously is also valid for H^0 → A^0 Z^0 and Z^0 → H^0 A^0. Note that couplings usually appear quadratically in matrix elements.

parm  HiggsH1:coup2d   (default = 1.)
The h^0(H_1^0) coupling to down-type quarks.

parm  HiggsH1:coup2u   (default = 1.)
The h^0(H_1^0) coupling to up-type quarks.

parm  HiggsH1:coup2l   (default = 1.)
The h^0(H_1^0) coupling to (charged) leptons.

parm  HiggsH1:coup2Z   (default = 1.)
The h^0(H_1^0) coupling to Z^0.

parm  HiggsH1:coup2W   (default = 1.)
The h^0(H_1^0) coupling to W^+-.

parm  HiggsH1:coup2Hchg   (default = 0.)
The h^0(H_1^0) coupling to H^+- (in loops). Is sin(beta - alpha) + cos(2 beta) sin(beta + alpha) / (2 cos^2theta_W) in the MSSM.

parm  HiggsH2:coup2d   (default = 1.)
The H^0(H_2^0) coupling to down-type quarks.

parm  HiggsH2:coup2u   (default = 1.)
The H^0(H_2^0) coupling to up-type quarks.

parm  HiggsH2:coup2l   (default = 1.)
The H^0(H_2^0) coupling to (charged) leptons.

parm  HiggsH2:coup2Z   (default = 1.)
The H^0(H_2^0) coupling to Z^0.

parm  HiggsH2:coup2W   (default = 1.)
The H^0(H_2^0) coupling to W^+-.

parm  HiggsH2:coup2Hchg   (default = 0.)
The H^0(H_2^0) coupling to H^+- (in loops). Is cos(beta - alpha) + cos(2 beta) cos(beta + alpha) / (2 cos^2theta_W) in the MSSM.

parm  HiggsH2:coup2H1H1   (default = 1.)
The H^0(H_2^0) coupling to a h^0(H_1^0) pair. Is cos(2 alpha) cos(beta + alpha) - 2 sin(2 alpha) sin(beta + alpha) in the MSSM.

parm  HiggsH2:coup2A3A3   (default = 1.)
The H^0(H_2^0) coupling to an A^0(H_3^0) pair. Is cos(2 beta) cos(beta + alpha) in the MSSM.

parm  HiggsH2:coup2H1Z   (default = 0.)
The H^0(H_2^0) coupling to a h^0(H_1^0) Z^0 pair. Vanishes in the MSSM.

parm  HiggsH2:coup2A3H1   (default = 0.)
The H^0(H_2^0) coupling to an A^0(H_3^0) h^0(H_1^0) pair. Vanishes in the MSSM.

parm  HiggsH2:coup2HchgW   (default = 0.)
The H^0(H_2^0) coupling to a H^+- W-+ pair. Is sin(beta - alpha) in the MSSM.

parm  HiggsA3:coup2d   (default = 1.)
The A^0(H_3^0) coupling to down-type quarks.

parm  HiggsA3:coup2u   (default = 1.)
The A^0(H_3^0) coupling to up-type quarks.

parm  HiggsA3:coup2l   (default = 1.)
The A^0(H_3^0) coupling to (charged) leptons.

parm  HiggsA3:coup2H1Z   (default = 1.)
The A^0(H_3^0) coupling to a h^0(H_1^0) Z^0 pair. Is cos(beta - alpha) in the MSSM.

parm  HiggsA3:coup2H2Z   (default = 1.)
The A^0(H_3^0) coupling to a H^0(H_2^0) Z^0 pair. Is sin(beta - alpha) in the MSSM.

parm  HiggsA3:coup2Z   (default = 0.)
The A^0(H_3^0) coupling to Z^0. Vanishes in the MSSM.

parm  HiggsA3:coup2W   (default = 0.)
The A^0(H_3^0) coupling to W^+-. Vanishes in the MSSM.

parm  HiggsA3:coup2H1H1   (default = 0.)
The A^0(H_3^0) coupling to a h^0(H_1^0) pair. Vanishes in the MSSM.

parm  HiggsA3:coup2Hchg   (default = 0.)
The A^0(H_3^0) coupling to H^+-. Vanishes in the MSSM.

parm  HiggsA3:coup2HchgW   (default = 1.)
The A^0(H_3^0) coupling to a H^+- W-+ pair. Is 1 in the MSSM.

parm  HiggsHchg:tanBeta   (default = 5.)
The tan(beta) value, which leads to an enhancement of the H^+- coupling to down-type fermions and suppression to up-type ones. The same angle also appears in many other places, but this particular parameter is only used for the charged-Higgs case.

parm  HiggsHchg:coup2H1W   (default = 1.)
The H^+- coupling to a h^0(H_1^0) W^+- pair. Is cos(beta - alpha) in the MSSM.

parm  HiggsHchg:coup2H2W   (default = 0.)
The H^+- coupling to a H^0(H_2^0) W^+- pair. Is sin(beta - alpha) in the MSSM.

Another set of parameters are not used in the production stage but exclusively for the description of angular distributions in decays.

mode  HiggsH1:parity   (default = 1; minimum = 0; maximum = 3)
possibility to modify angular decay correlations in the decay of a h^0(H_1) decay Z^0 Z^0 or W^+ W^- to four fermions. Currently it does not affect the partial width of the channels, which is only based on the above parameters.
option 0 : isotropic decays.
option 1 : assuming the h^0(H_1) is a pure scalar (CP-even), as in the MSSM.
option 2 : assuming the h^0(H_1) is a pure pseudoscalar (CP-odd).
option 3 : assuming the h^0(H_1) 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  HiggsH1:etaParity   (default = 0.)
The eta value of CP-violation in the HiggsSM:parity = 3 option.

mode  HiggsH2:parity   (default = 1; minimum = 0; maximum = 3)
possibility to modify angular decay correlations in the decay of a H^0(H_2) decay Z^0 Z^0 or W^+ W^- to four fermions. Currently it does not affect the partial width of the channels, which is only based on the above parameters.
option 0 : isotropic decays.
option 1 : assuming the H^0(H_2) is a pure scalar (CP-even), as in the MSSM.
option 2 : assuming the H^0(H_2) is a pure pseudoscalar (CP-odd).
option 3 : assuming the H^0(H_2) 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  HiggsH2:etaParity   (default = 0.)
The eta value of CP-violation in the HiggsSM:parity = 3 option.

mode  HiggsA3:parity   (default = 2; minimum = 0; maximum = 3)
possibility to modify angular decay correlations in the decay of a A^0(H_3) decay Z^0 Z^0 or W^+ W^- to four fermions. Currently it does not affect the partial width of the channels, which is only based on the above parameters.
option 0 : isotropic decays.
option 1 : assuming the A^0(H_3) is a pure scalar (CP-even).
option 2 : assuming the A^0(H_3) is a pure pseudoscalar (CP-odd), as in the MSSM.
option 3 : assuming the A^0(H_3) 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  HiggsA3:etaParity   (default = 0.)
The eta value of CP-violation in the HiggsSM:parity = 3 option.