MadGraph5_aMC@NLO

pT bias and MLM matching

Asked by andlessa

Hi,

I'm trying to generate some merged samples ( p p > X X + p p > X X j ) using the MLM matching scheme.
In order to populate the tail of the jet pT distrbitution I was trying to use the bias module with the following options:

ptj_bias = bias_module ! Bias type of bias, [None, ptj_bias, -custom_folder-]
 {'ptj_bias_target_ptj': 100.0, 'ptj_bias_enhancement_power': 1.0} = bias_parameters

However it does not seem to increase my statistics at high pT and I get unweighted events after showering with Pythia 8.
Am I doing something wrong?

Best,

-Andre

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Olivier Mattelaer
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Olivier Mattelaer (olivier-mattelaer) said : 		#1

I think that for the ptj_bias module to work with MLM matching.
You have to generate each multiplicity independently.
Did you do that?

Cheers,

Olivier

> On 5 Jan 2023, at 22:10, andlessa <email address hidden> wrote:
>
> New question #704299 on MadGraph5_aMC@NLO:
> https://answers.launchpad.net/mg5amcnlo/+question/704299
>
> Hi,
>
> I'm trying to generate some merged samples ( p p > X X + p p > X X j ) using the MLM matching scheme.
> In order to populate the tail of the jet pT distrbitution I was trying to use the bias module with the following options:
>
> ptj_bias = bias_module ! Bias type of bias, [None, ptj_bias, -custom_folder-]
> {'ptj_bias_target_ptj': 100.0, 'ptj_bias_enhancement_power': 1.0} = bias_parameters
>
> However it does not seem to increase my statistics at high pT and I get unweighted events after showering with Pythia 8.
> Am I doing something wrong?
>
> Best,
>
> -Andre
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Revision history for this message
andlessa (lessa-a-p) said : 		#2

Thanks. I was trying to do everything in one go:

generate p p > x x~
add process p p > x x~ j

and then generate events with the pT bias and MLM matching.

So this will not work, right?

Revision history for this message
Best Olivier Mattelaer (olivier-mattelaer) said : 		#3

I do not think. that it will.

Olivier

> On 5 Jan 2023, at 23:30, andlessa <email address hidden> wrote:
>
> Question #704299 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/704299
>
> Status: Answered => Open
>
> andlessa is still having a problem:
> Thanks. I was trying to do everything in one go:
>
> generate p p > x x~
> add process p p > x x~ j
>
> and then generate events with the pT bias and MLM matching.
>
> So this will not work, right?
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Revision history for this message
andlessa (lessa-a-p) said : 		#4

Thanks Olivier Mattelaer, that solved my question.