Problem getting decay width at masses greater than 80 GeV

Asked by Kevin Alberto Urquía Calderón on 2021-06-06

I am using the model SM_HeavyN_NLO and SM_HeavyN_Gen3Mass_NLO, and I'm trying to calculate the decay width of a heavy neutrino into three fermions. Basically:

generate n1 > ff ff ff

Where I defined ff as all fermions. I have also added "set mn1 scan:range(20,120,2)" to scan the mass range that I want, but every time I get to 80 GeV, the value of the decay width skyrockets, there a less than ten events generated and I have an uncertainty ridiculously big.

I was working earlier with other decays, specifically n1 > e- mu+ vm and I did not have the same problem.

How can I fix this?

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Jack Y. Araz (jackaraz) said :
#1

Hi

This is not related to MadAnalysis please refer to MadGraph instead.

--
Jack Y. Araz

> On 6 Jun 2021, at 4:55 pm, Kevin Alberto Urquía Calderón <email address hidden> wrote:
>
> [EXTERNAL EMAIL]
>
> New question #697426 on MadAnalysis 5:
> https://answers.launchpad.net/madanalysis5/+question/697426
>
> I am using the model SM_HeavyN_NLO and SM_HeavyN_Gen3Mass_NLO, and I'm trying to calculate the decay width of a heavy neutrino into three fermions. Basically:
>
> generate n1 > ff ff ff
>
> Where I defined ff as all fermions. I have also added "set mn1 scan:range(20,120,2)" to scan the mass range that I want, but every time I get to 80 GeV, the value of the decay width skyrockets, there a less than ten events generated and I have an uncertainty ridiculously big.
>
> I was working earlier with other decays, specifically n1 > e- mu+ vm and I did not have the same problem.
>
> How can I fix this?
>
> --
> You received this question notification because you are an answer
> contact for MadAnalysis 5.

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