Changes in EWDIM6 between v2_2_3 and v2_4_0

Dear Kristin,

So many stuff changed between those two versions. You can look at the Updates Note to have the main list of modification done in the code.
The one impacting you here is the modification of the default run_card.dat where the parameter cut_decays pass from True to False.
I guess this can explain most of your findings. Below I ran some test to convince myself that everything seems coherent between those two versions:

Cheers,

Olivier

PS: Here is the tests that I ran:

I have run the following script in 2.4.1:
> import model EWdim6
> generate e+ e- > w+ w-, w+ > e+ ve, w- > mu- vm~
> output
> launch
> set cut_decays = T
> set dim6 1 scan1:[1 if i ==1 else 0 for i in range(6)]
> set dim6 2 scan1:[1 if i ==2 else 0 for i in range(6)]
> set dim6 3 scan1:[1 if i ==3 else 0 for i in range(6)]
> set dim6 4 scan1:[1 if i ==4 else 0 for i in range(6)]
> set dim6 5 scan1:[1 if i ==5 else 0 for i in range(6)]

For 2.2.3, I used the following script (not the same since the above syntax is not supported on such old version)
> import model EWdim6
> generate e+ e- > w+ w-, w+ > e+ ve, w- > mu- vm~
> output
> launch
> set LEP 1000
> set dim6 1 0
> set dim6 2 0
> set dim6 3 0
> set dim6 4 0
> set dim6 5 0
> launch
> set dim6 1 1
> set dim6 2 0
> set dim6 3 0
> set dim6 4 0
> set dim6 5 0
> launch
> set dim6 1 0
> set dim6 2 1
> set dim6 3 0
> set dim6 4 0
> set dim6 5 0
> launch
> set dim6 1 0
> set dim6 2 0
> set dim6 3 1
> set dim6 4 0
> set dim6 5 0
> launch
> set dim6 1 0
> set dim6 2 0
> set dim6 3 0
> set dim6 4 1
> set dim6 5 0
> launch
> set dim6 1 0
> set dim6 2 0
> set dim6 3 0
> set dim6 4 0
> set dim6 5 1

my results are:
#run_name dim6#1 dim6#2 dim6#3 dim6#4 dim6#5 cross(pb)2.4.1 cross(pb)2.2.3
run_01 0 0 0 0 0 0.012628 0.012605
run_02 1 0 0 0 0 0.0127511 0.012697
run_03 0 1 0 0 0 0.0128729 0.012935
run_04 0 0 1 0 0 0.012796 0.012828
run_05 0 0 0 1 0 0.0132243 0.013255
run_06 0 0 0 0 1 0.0127377 0.012676

Sounds good so far.

To double check I did the same with dim6 parameter set to an higher value (10)
In that case my result are:
#run_name dim6#1 dim6#2 dim6#3 dim6#4 dim6#5 cross(pb)2.4.1 cross(pb)2.2.3
run_01 0 0 0 0 0 0.012628 0.012605
run_02 10 0 0 0 0 0.024178 0.024182
run_03 0 10 0 0 0 0.0188816 0.018878
run_04 0 0 10 0 0 0.01561 0.01568
run_05 0 0 0 10 0 0.058469 0.058284
run_06 0 0 0 0 10 0.0128699 0.012893

Sounds to confirm that I do not see any increase in the cross-section.

Cheers,

Olivier

> On May 23, 2016, at 17:37, Kristin Lohwasser <email address hidden> wrote:
>
> Question #294091 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/294091
>
> Description changed to:
> Dear developers,
>
> we were wondering, if there are any changes introduced between v2_2_3
> and v2_4_0 that could explain the following features for WW production
> and subsequent decays into leptons:
>
> -- a (non-physical) dip around 0 for the polar angle phi between the
> decay lepton and the W in the rest frame (for SM and also EWDim6
> operators set)
>
> -- an increase in cross section of >20%
>
> -- Problems in relating the angles and production properties for the different CWW, CW and CB operators to the corresponding ATGC parameters ( see e.g. : M. Bilenky, J.L. Kneur, F.M. Renard, and D. Schildknecht. Trilinear couplings
> among the electroweak vector bosons and their determination at lep2. Nuclear Physics B, 409(1):22–68, 1993.)
> These were present mainly for CW and CB (for CWW, this looked mainly very good).
>
> We see some improvements changing to v2_4_0, but were also wondering
> about choosing Random Numbers correctly, what would be a recommendation
> for them?
>
> the process line is:
> generate e+ e- > w+ w-, w+ > e+ ve, w- > mu- vm~
>
> Thanks & Cheers
> Kristin
>
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.