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Herwig  7.2.1
Interfaces defined for the Herwig::MEPP2GammaGammaPowheg class.
Brief class description:
TheMEPP2GammaGammaPowheg class implements gamma gamma production at NLO
See also Herwig::MEPP2GammaGammaPowheg

Name: ScalePreFactor
Type: Parameter

Description:
Prefactor to change factorization/renormalisation scale
Default value: 1
Minimum value: 0.1
Maximum value: 10

Name: ScaleChoice
Type: Switch

Description:
The scale choice to use
Registered options:
0(pT)
Use the pT of the photons
1(MGammaGamma)
Use the mass of the photon pair
Default value: 0

Name: preQCDqqbarqbar
Type: Parameter

Description:
The constant for the Sudakov overestimate for the q qbar -> V Gamma +g with emission from the qbar
Default value: 23
Minimum value: 0
Maximum value: 1000

Name: preQCDqqbarq
Type: Parameter

Description:
The constant for the Sudakov overestimate for the q qbar -> V Gamma +g with emission from the q
Default value: 23
Minimum value: 0
Maximum value: 1000

Name: ShowerAlphaQED
Type: Reference to objects of class Herwig::ShowerAlpha

Description:
Reference to the object calculating the QED coupling for the shower

Name: ShowerAlphaQCD
Type: Reference to objects of class Herwig::ShowerAlpha

Description:
Reference to the object calculating the QCD coupling for the shower

Name: SupressionScaleChoice
Type: Switch

Description:
Choice of the supression scale
Registered options:
0(Fixed)
Use a fixed scale
1(Variable)
Use the pT of the hard process as the scale
Default value: 0

Name: SupressionScale
Type: Parameter

Description:
The square of the scale for the supression function
Default value: 20
Minimum value: 0

Name: SupressionFunction
Type: Switch

Description:
Choice of the supression function
Registered options:
0(None)
Default POWHEG approach
1(ThetaFunction)
Use theta functions at scale Lambda
2(Smooth)
Supress high pT by pt^2/(pt^2+lambda^2)
Default value: 0

Name: FixedAlphaS
Type: Switch

Description:
Use a fixed value of alphaS
Registered options:
0(No)
Use a running alphaS
1(Yes)
Use a fixed alphaS
Default value: 0

Name: AlphaS
Type: Parameter

Description:
The value of alphaS to use if using a fixed alphaS
Default value: 0.118
Minimum value: 0
Maximum value: 0.2

Name: MaximumFlavour
Type: Integer parameter

Description:
The maximum flavour allowed for the incoming quarks
Default value: 5
Minimum value: 1
Maximum value: 5

Name: Contribution
Type: Switch

Description:
Which contributions to the cross section to include
Registered options:
0(LeadingOrder)
Just generate the leading order cross section
1(PositiveNLO)
Generate the positive contribution to the full NLO cross section
2(NegativeNLO)
Generate the negative contribution to the full NLO cross section
Default value: 1

Name: ThreeBodyProcess
Type: Switch

Description:
The possible three body processes to include
Registered options:
0(All)
Include all processes
1(qqbar)
Only include q qbar -> gamma gamma g processes
2(qg)
Only include q g -> gamma gamma q processes
3(gqbar)
Only include g qbar -> gamma gamma qbar processes
Default value: 0

Name: Process
Type: Switch

Description:
Which processes to include
Registered options:
0(All)
Include all the processes
1(GammaGamma)
Only include gamma gamma
2(VJet)
Only include gamma + jet
3(Hard)
Only include hard radiation contributions
Default value: 0

There may be interfaces inherited from the Herwig::HwMEBase class.