# Invariant mass specifying vertex

Dear community,

I am new to madanalysis and trying to plot an invariant mass of leptons, coming from the same vertex. The Issue is that I have more that one such vertices. I've tried to find a solution and come up so far only with an idea that I could use the information about the mother particles to do so.

To be more specific, this is the process (It's in in NMSSM and sferm state for sfermions s for simplicity they are not taken into account): g g > h01 > n3 n2 , n2 > n1 l+ l- /sferm , (n3 > n2 l+ l- /sferm , n2 > n1 l+ l-/sferm) (I would attach the graph but don't see such an option). So, for example, I have l+ l- that has the following parents: l+ l- < z < n2 < n3 < h01 and l+ l- < z < n2 < h01. There is no problem with plotting M(l- < z < n2 < n3 l+ < z < n2 < n3) but if I want to plot M(l- < z < n2 l+ < z < n2), I get the historgam for all combinations of leptons in both chains. To deal with this, I tried plotting M(l- < z < n2 < h01 l+ < z < n2 < h01) but the histogram appears empty. Same holds for easier plots: PT(l+ < z < n3) works just fine but PT(l+ < z < n3 < h01) is empty.

My question is: if there is a way to distinguish between those branches and/or achieve the desired result using a different approach?

## Question information

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Anastasia
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2019-03-18
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2019-03-18
2019-03-18
 Benjamin Fuks (fuks) said on 2019-03-17: #1

Hi Anastasia,

With such a complicated pattern, the only thing I can recommend is to use the expert mode where you would have more control on the conditions.

Cheers,

Benjamin

> On 17 Mar 2019, at 15:57 , Anastasia <email address hidden> wrote:
>
> New question #679284 on MadAnalysis 5:
>
> Dear community,
>
> I am new to madanalysis and trying to plot an invariant mass of leptons, coming from the same vertex. The Issue is that I have more that one such vertices. I've tried to find a solution and come up so far only with an idea that I could use the information about the mother particles to do so.
>
> To be more specific, this is the process (It's in in NMSSM): g g > h01 > n3 n2 , n2 > n1 l+ l- /sferm , (n3 > n2 l+ l- /sferm , n2 > n1 l+ l-/sferm) (I would attach the graph but don't see such an option). So, for example, I have l+ l- that has the following parents: l+ l- < z < n2 < n3 < h01 and l+ l- < z < n2 < h01. There is no problem with plotting M(l- < z < n2 < n3 l+ < z < n2 < n3) but if I want to plot M(l- < z < n2 l+ < z < n2), I get the historgam for all combinations of leptons in both chains. To deal with this, I tried plotting M(l- < z < n2 < h01 l+ < z < n2 < h01) but the histogram appears empty. Same holds for easier plots: PT(l+ < z < n3) works just fine but PT(l+ < z < n3 < h01) is empty.
>
> My question is: if there is a way to distinguish between those branches and/or achieve the desired result using a different approach?
>
>
> --

 Anastasia (assimptota) said on 2019-03-18: #2

Hi Benjamin,

Thanks for your reply. I am still a little bit confused why the idea with the parental particles doesn't work. Let's have a more simple process g g > h01 > n3 n2 , n2 > n1 l+ l- /sferm (so only the decay n2 -> n1 z*, z* -> l+ l- is relevant) . Why can I plot PT(l+ < z < n2) but not PT(l+ < z < n2 < h01)? It seems as if h01 is not considered as a parent for l+.

 Anastasia (assimptota) said on 2019-03-18: #3

I've looked at the *.lhe-files and realized that there is no information about the h01 stored so the mother particle of n2 is g directly. Plotting PT(l+ < z < n2 < g) works, though the fact that the information about the s-channel mediator is lost confuses me.

 Benjamin Fuks (fuks) said on 2019-03-18: #4

Unfortunately, we can't store all the information (we don't want the event file to become large). If you really need it, the best for now is to hack the code, or to work, as I said, at the level of the expert mode.

Cheers,

Benjamin

> On 18 Mar 2019, at 07:02 , Anastasia <email address hidden> wrote:
>
> Question #679284 on MadAnalysis 5 changed:
>
> I've looked at the *.lhe-files and realized that there is no information
> about the h01 stored so the mother particle of n2 is g directly.
> Plotting PT(l+ < z < n2 < g) works, though the fact that the
> information about the s-channel mediator is lost confuses me.
>
> --