ttH at high HT

Hi Clement,

First one question, did you decay any of the particle (h/top?) if not this might be the reason of the problem (since you do not have jet and therefore HT is 0 for all PS point).

A second possibility is that the phase-space integration fails to find the correct region of integration due to the strong cut.
The HT cut is indeed not include in the initial grid of the phase-space integration. So the solution to help on this is to put a stronger cut on
ptj.

Cheers,

Olivier

On Nov 17, 2014, at 12:46 PM, helsens clement <email address hidden> wrote:

> New question #257756 on MadGraph5_aMC@NLO:
> https://answers.launchpad.net/mg5amcnlo/+question/257756
>
> Hello,
>
> I am trying to generate at sqrt(s)=100TeV high HT ttH events (would also need ttbb Background later) but I get 0 cross section when I try to set the HT cut to 2TeV with Madgraph5. I certainly doing something wrong.
> So I am wondering what would be the best solution to generate high HT ttH and ttbb final states.
>
> Thanks,
> Clement
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Hi Olivier,

Thanks for the prompt reply!

no I haven't decayed the tops nor the Higgs, I thought the ihtmin cut could have done the job:

======
2000 = ihtmin !inclusive Ht for all partons (including b)
======

but seems not

I am now decaying the tops and higgs:

generate p p > t t~ h, t > j j b, t~ > mu- vm~ b~, h > b b~
add process p p > t t~ h, t > mu+ vm b, t~ > j j b~, h > b b~
add process p p > t t~ h, t > j j b, t~ > j j b~, h > b b~

but it takes forever.
So you are suggesting to raise the jet pT cuts as well?

Thanks,
Clement

Hi,

> ======
> 2000 = ihtmin !inclusive Ht for all partons (including b)
> ======

This is the sum of the light jet and of the b-jet.
You can change this behavior in SubProcesses/cuts.f
if you want.

> but it takes forever.
> So you are suggesting to raise the jet pT cuts as well?

This might help in the decay case.
But I would actually suggest that you modify the cut to what you need, and then use MadSpin for the decay.
This would be the more efficient.

Cheers,

Olivier

On Nov 17, 2014, at 3:01 PM, helsens clement <email address hidden> wrote:

> Question #257756 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/257756
>
> Status: Answered => Open
>
> helsens clement is still having a problem:
> Hi Olivier,
>
> Thanks for the prompt reply!
>
> no I haven't decayed the tops nor the Higgs, I thought the ihtmin cut
> could have done the job:
>
> ======
> 2000 = ihtmin !inclusive Ht for all partons (including b)
> ======
>
> but seems not
>
> I am now decaying the tops and higgs:
>
> generate p p > t t~ h, t > j j b, t~ > mu- vm~ b~, h > b b~
> add process p p > t t~ h, t > mu+ vm b, t~ > j j b~, h > b b~
> add process p p > t t~ h, t > j j b, t~ > j j b~, h > b b~
>
> but it takes forever.
> So you are suggesting to raise the jet pT cuts as well?
>
> Thanks,
> Clement
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.