subprocess analysis with madanalysis

Hi,

You can't do that. MadAnalysis will analyse the full sample directly. For doing what you want, you would need one sample per subprocess.

Regards,

Benjamin

> On 20 Feb 2018, at 23:47 , zheng <email address hidden> wrote:
>
> New question #664727 on MadAnalysis 5:
> https://answers.launchpad.net/madanalysis5/+question/664727
>
> Hello,
>
> I'm studying preliminary information of the p p > t h j process by analysing the 'events.lhe' file at parton level with madanalysis. Four subprocess folders are generated.
>
> I'm wondering if the results from each subprocess is also stored separately somewhere so that I can analyse each subprocess and compare their separate contribution and also with the total at the same time. Or do I need to generate each subprocess separately to analyze and compare for this purpose? Thank you very much.
>
> Best regards,
> Ya-Juan
>
> --
> You received this question notification because you are an answer
> contact for MadAnalysis 5.
>

Thanks Benjamin Fuks, that solved my question.

Hello,

Following the same analysis, I have a question in using the 'reject' command for multiparticle rapidity.

I generated with Madgraph two process 1 ub>thd 2 cb>ths at the same time and analysed the lhe file. I wanted to see the effect of rapidity cut for the (thj). The folloing command is what I imposed.

ma5>define thj = t h1 j
ma5>plot Y (thj)
ma5>reject Y (thj) < 0
ma5>plot Y (thj)
ma5>reject Y (thj) < 0.05
ma5>plot Y (thj)
ma5>reject Y (thj) < 0.10
ma5>plot Y (thj)
ma5>reject Y (thj) < 0.15
ma5>plot Y (thj)
ma5>reject Y (thj) < 0.20
ma5>plot Y (thj)
ma5>submit ../Ythj_12ubcb

The number after cut is also copied as below,

Cuts
Signal (S)
Background (B)
S vs B
Initial (no cut)
130.159 +/- 0.251
Cut 1
38.49 +/- 5.21
Cut 2
36.75 +/- 5.14
Cut 3
35.06 +/- 5.06
Cut 4
33.33 +/- 4.98
Cut 5
31.61 +/- 4.89

From the Y (thj) distribution plot before any cut, I expect the command 'reject Y (thj) < 0' would keep more than half events (Hope there's some way that I can show you the plot). However, the cross section number is reduced from 13.02fb to 3.85fb, with only 1/3 of events left. How should I understand the inconsistency of exceptions from the plot? Do I have some misunderstanding in the command 'reject', or reading the output number after cut? Thank you very much.

Best regards,
Ya-Juan

Hi,

Please provide me the working directory generated by MA5.

Cheers,

Benjamin

> On 9 Mar 2018, at 14:22 , zheng <email address hidden> wrote:
>
> Question #664727 on MadAnalysis 5 changed:
> https://answers.launchpad.net/madanalysis5/+question/664727
>
> Status: Solved => Open
>
> zheng is still having a problem:
> Hello,
>
> Following the same analysis, I have a question in using the 'reject'
> command for multiparticle rapidity.
>
> I generated with Madgraph two process 1 ub>thd 2 cb>ths at the same time
> and analysed the lhe file. I wanted to see the effect of rapidity cut
> for the (thj). The folloing command is what I imposed.
>
> ma5>define thj = t h1 j
> ma5>plot Y (thj)
> ma5>reject Y (thj) < 0
> ma5>plot Y (thj)
> ma5>reject Y (thj) < 0.05
> ma5>plot Y (thj)
> ma5>reject Y (thj) < 0.10
> ma5>plot Y (thj)
> ma5>reject Y (thj) < 0.15
> ma5>plot Y (thj)
> ma5>reject Y (thj) < 0.20
> ma5>plot Y (thj)
> ma5>submit ../Ythj_12ubcb
>
> The number after cut is also copied as below,
>
> Cuts
> Signal (S)
> Background (B)
> S vs B
> Initial (no cut)
> 130.159 +/- 0.251
> Cut 1
> 38.49 +/- 5.21
> Cut 2
> 36.75 +/- 5.14
> Cut 3
> 35.06 +/- 5.06
> Cut 4
> 33.33 +/- 4.98
> Cut 5
> 31.61 +/- 4.89
>
>> From the Y (thj) distribution plot before any cut, I expect the command
> 'reject Y (thj) < 0' would keep more than half events (Hope there's some
> way that I can show you the plot). However, the cross section number is
> reduced from 13.02fb to 3.85fb, with only 1/3 of events left. How
> should I understand the inconsistency of exceptions from the plot? Do I
> have some misunderstanding in the command 'reject', or reading the
> output number after cut? Thank you very much.
>
> Best regards,
> Ya-Juan
>
> --
> You received this question notification because you are an answer
> contact for MadAnalysis 5.
>

Hi, I shared the files created by MA5 in dropbox, please see if you can read it. Thank you very much.

https://www.dropbox.com/sh/hu4iull4g5x32x4/AABFWg2Z50kFa4g6eXgcNREza?dl=0

Best regards,
Ya-Juan

Hi Ya-Juan,

I have checked the code and it does well what it is supposed to do. As soon as one of the considered particle has a negative rapidity, the event is rejected. Remember that for each event, you have three entries in the histogram and that a single one of them being negative is sufficient to reject the event.

Cheers,

Benjamin

> On 12 Mar 2018, at 08:58 , zheng <email address hidden> wrote:
>
> Question #664727 on MadAnalysis 5 changed:
> https://answers.launchpad.net/madanalysis5/+question/664727
>
> Status: Answered => Open
>
> zheng is still having a problem:
>
> Hi, I shared the files created by MA5 in dropbox, please see if you can read it. Thank you very much.
>
> https://www.dropbox.com/sh/hu4iull4g5x32x4/AABFWg2Z50kFa4g6eXgcNREza?dl=0
>
> Best regards,
> Ya-Juan
>
> --
> You received this question notification because you are an answer
> contact for MadAnalysis 5.
>

Hi Benjamin.

thank you very much for your explanation. It seems MA5 are rejecting events by counting the rapidity of each particle independently even though it is defined as a multiparticle.

I assumed that defining multi particle thj would result in a( thj) system and keeps the four momentum of this multiparticle from the sum of the three. Therefore, I thought Y(thj) would calculate the rapidity of this multiparticle system from the four momentum. I wanted to reject the negative rapidity events of this system. In this case, do I have to make my own program or is there function in MA5 defined for this purpose?

Best regards,
Ya-Juan

Thanks Benjamin Fuks, that solved my question.