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! This file is for the user to set the different parameters of MadLoop.
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! The name of the variable to define must start with the '#' sign and then
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! the value should be put immediately on the next line.
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! =================================================================================
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! The parameters below set the stability checks of MadLoop at run time
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! =================================================================================
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! Decide in which mode to set CutTools at runtime.
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! The possible modes are:
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! imode:| actions performed by ctsxcut:
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! 0 | (dp_dir,dp_inv)-> dp_Atest -> stable -> (only if stable=.false.) ->
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! | (mp_dir,mp_inv)-> mp_Atest -> stable
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! 1 | (dp_dir) -> dp_Ntest -> stable
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! 2 | (dp_inv) -> dp_Ntest -> stable
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! 3 | (dp_dir,dp_inv)-> dp_Atest -> stable
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! 4 | (mp_dir) -> mp_Ntest -> stable
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! 5 | (mp_inv) -> mp_Ntest -> stable
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! 6 | (mp_dir,mp_inv)-> mp_Atest -> stable
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! -1 | Special mode, see below for the negative ones.
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! Due to the architecture of the program, you are better off
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! rerunning the full PS point in quadruple precision than just a single loop
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! because the two things would almost take the same time. So '-1' is always
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! In the negative mode -1, MadLoop first evaluates each PS points in modes 1 and 2,
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! yielding results Res1 and Res2, and then check if:
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! (Res1-Res2)/(2*(Res1+Res2)< MLStabThres
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! If it is not the case, MadLoop evaluates again the PS point in modes 4 and 5,
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! yielding results Res4 and Res5, and then check if:
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! (Res4-Res5)/(2*(Res4+Res5)< MLStabThres
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! If it is the case then the unstable phase-space point could be cured. If it is
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! not the case, MadLoop outputs a warning.
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! Notice that MLStabThres is used only when CTModeRun is negative.
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! You can add other evaluation method to check for the stability in DP and QP.
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! Below you can chose if you want to use zero, one or two rotations of the PS point
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! By default, MadLoop is allowed to slightly deform the Phase-Space point in input
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! so to insure perfect onshellness of the external particles and perfect energy-momentum
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! conservation. The deformation is minimal and such that it leaves the input PS point
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! unchanged if it already satisfies the physical condiditions mentioned above.
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! This integer values select what is the method to be employed preferably to restore this
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! precision. It can take the following values:
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! -1 :: No method is used for double precision computations, and method 2 will be used
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! preferentially when quadruple precision (for which this precision improvement
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! is mandatory, otherwise quadruple precision is pointless)
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! 1 :: This methods imitates what is done in PSMC, namely
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! a) Set the space-like momentum of the last external particle to be the
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! opposite of the sum of the others (with a minus sign for the initial states).
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! b) Rescale all final state space-like momenta by a fixed value x computed such
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! that energy is conserved when particles are put exactly onshell. This value
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! is determined numericaly via Ralph-Newton's method.
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! c) Set all energies to have particles exactly onshell.
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! 2 :: This method applies a shift to the energy and the x and y components of the first
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! initial state momentum in order to restore exact energy momentum conservation after
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! particles have been put exactly onshell via a shift of the z component of their
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! =================================================================================
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! The parameters below set two CutTools internal parameters accessible to the user.
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! =================================================================================
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! Choose here what library to chose for CutTools to compute the scalar loops of the
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! master integral basis. The choices are as follows:
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! Choose here the stability threshold used within CutTools to decide when to go to
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! =================================================================================
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! The parameters below set the general behavior of MadLoop for the initialization
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! =================================================================================
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! Decide in which mode to set CutTools when performing MadLoop's initialization of
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! the helicity (and possibly loop) filter. The possible modes are:
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! imode:| actions performed by ctsxcut:
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! 0 | (dp_dir,dp_inv)-> dp_Atest -> stable -> (only if stable=.false.) ->
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! | (mp_dir,mp_inv)-> mp_Atest -> stable
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! 1 | (dp_dir) -> dp_Ntest -> stable
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! 2 | (dp_inv) -> dp_Ntest -> stable
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! 3 | (dp_dir,dp_inv)-> dp_Atest -> stable
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! 4 | (mp_dir) -> mp_Ntest -> stable
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! 5 | (mp_inv) -> mp_Ntest -> stable
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! 6 | (mp_dir,mp_inv)-> mp_Atest -> stable
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! CheckCycle sets on how many PS points trials the initialization filters must be
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! obtained. As long as MadLoop does not find that many consecutive PS points for
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! which the filters are the same, it will start over but only a maximum of
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! Setting the threshold for deciding wether a numerical contribution is analytically
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! The setting below is recommended to be on as it allows to systematically used the
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! first PS point thrown at ML5 to be used for making sure that the helicity filter
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! read from HelFilter.dat is consistent as it might be no longer up to date with
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! certain changes of the paramaters by the user.
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#DoubleCheckHelicityFilter
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! Some loop contributions may be zero for some helicities which are however
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! contributing. In order to save their computing time, you can chose here to try
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! to filter them out. The gain is typically minimal, so it is turned off by default.
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! This decides wether consecutive consistency for the loop filtering setup is also
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! This decides wether consecutive consistency for the helicity filtering setup is also
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! required. Better to set it to false as it can cause problems for unstable processes.
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/* End of param file */