ickkw default = 1?

Hi Josh,

This was introduced in 2.3.0 were the run_card passed from a static default to a default tailored to the generation.
The logic is to have more sensitive default when a user just blindly run madgraph.

The list of parameter which are process dependent are (so far):
For 2> N LO processes:
nhel: set to 1 for loop induced processes
ickkw: set to one in presence of process with multiple QCD multiplicity
maxjetflavor: set to 4/5 depending if the model is a 4/5 flavor model
asrwgtflavor: set to 4/5 depending if the model is a 4/5 flavor model
lpp1/lpp2: set to 0 (no pdf) if the initial state is not proton/photon
ebeam1/ebeam2 : set to 500 if the initial particle are electron/positron

Additionally if ickkw was set to one:
the following apply:
use_syst: set to false
xqcut set to 30
drjj set to 0
drjl set 0
sys_alpsfact set to 0.5 1 2

For 1> N LO processes:
All the above plus:
use_syst set to False
all the cut are modified to be set to “no cut” (either 0 or -1)
contrary to 2.2.x, the cuts are now applied for 1>N processes.

For NLO processes:
maxjetflavor: set to 4/5 depending if the model is a 4/5 flavor model
lpp1/lpp2: set to 0 (no pdf) if the initial state is not proton/photon
ebeam1/ebeam2 : set to 500 if the initial particle are electron/positron

For 1>N: all cuts are set to “no_cut”.

If you want the detail algorithm for how I decide if the ickkw=1 is set on 1. It is present in
madgraph/various/banner.py around line 1874 in the function create_default_for_process

I put it here as well (the 2.4.2 version to be exact).

      # Check if need matching
        min_particle = 99
        max_particle = 0
        for proc in proc_def:
            min_particle = min(len(proc[0]['legs']), min_particle)
            max_particle = max(len(proc[0]['legs']), max_particle)
        if min_particle != max_particle:
            #take one of the process with min_particle
            for procmin in proc_def:
                if len(procmin[0]['legs']) != min_particle:
                    continue
                else:
                    idsmin = [l['id'] for l in procmin[0]['legs']]
                    break
            matching = False
            for procmax in proc_def:
                if len(procmax[0]['legs']) != max_particle:
                    continue
                idsmax = [l['id'] for l in procmax[0]['legs']]
                for i in idsmin:
                    if i not in idsmax:
                        continue
                    else:
                        idsmax.remove(i)
                for j in idsmax:
                    if j not in [1,-1,2,-2,3,-3,4,-4,5,-5,21]:
                        break
                else:
                    # all are jet => matching is ON
                    matching=True
                    break

> On Jun 23, 2016, at 12:09, Josh McFayden <email address hidden> wrote:
>
> New question #295600 on MadGraph5_aMC@NLO:
> https://answers.launchpad.net/mg5amcnlo/+question/295600
>
> Hi everyone,
>
> It seems that at some point in v2.3.X the default ickkw run_card parameter changed to be =1 if a process involved additional partons, is that correct?
>
> Could you tell me what version this was introduced and exactly what logic controls this setting?
>
> As you probably well know by now, most ATLAS samples use CKKW-L merging for LO production and in this case we need ickkw=0 therefore the default value being changed to ickkw=1 is causing us some problems.
>
> Best,
>
> Josh.
>
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