Comment 6 for bug 1731086

Hi Emma,

Did you generate such file with use_syst=T?
If you do, what is the pdf dependencies for a given event?
(if you copy/paste such information here for one event, I can figure it myself)

To be sure, you are running with pdf reweighting in MLM set on ON right?
(my patch was fixing the fact that such option was most of the time set on OFF even if set on ON in the run_card)

Cheers,

Olivier

> On Nov 22, 2017, at 00:42, Emma Kuwertz <email address hidden> wrote:
>
> Hi Olivier,
>
> any news on this?
>
> Thanks,
> Emma
>
> --
> You received this bug notification because you are subscribed to
> MadGraph5_aMC@NLO.
> https://bugs.launchpad.net/bugs/1731086
>
> Title:
> Change in production xsecs in SUSY models in 2.6.0
>
> Status in MadGraph5_aMC@NLO:
> New
>
> Bug description:
> Hi there,
>
> I'm hoping that you can help us track this issue down, as it's holding
> up our validation of MadGraph 2.6.0. Emma Kuwertz and I found that
> between older and newer MadGraph releases, the cross section of p p >
> go go j processes changed by 50% or more. I set up and run out of the
> box:
>
> import model mssm
> generate p p > go go
> add process p p > go go j
> output -f
>
> in MadGraph 2.3.3 and 2.4.3. I run the same in MadGraph 2.6.0, but
> with `import model MSSM_SLHA2`. In both releases I then set the
> masses of all SUSY particles to be 10**9 GeV, except the gluino which
> is set to 1 TeV. All other parameters I leave as they are, out of the
> box, but a quick check suggests that there aren't wild new cuts that
> have appeared. With 2.3.3 the cross section I get is:
>
> Cross-section : 0.662 +- 0.00212 pb
>
> With 2.4.3 and 2.6.0, I get the same answer:
>
> Cross-section : 0.7888 +- 0.002181 pb
>
> There, the cross section files suggest that most of the difference is
> due to a large (>25%) change in g g > go go g. I don't see any
> difference in the PDFs that might cause such a change, though.
>
> In Emma's run inside the ATLAS framework, we were looking at more
> modest total cross section changes, but large changes to the go go j
> cross section (of order 50%) that led to significantly harder
> kinematics in one case than the other.
>
> Is there some known feature of the releases that would have caused
> these differences? I tried to look over the update notes, but I
> didn't find anything sinister.
>
>
> Thanks,
> Zach
>
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