missing momentum in ma5

Asked by Gabriele Ferretti on 2013-08-29

Hi,

is there a way to access the total missing momentum in ma5 running in "rookie" mode?
There are some observables that require that, and the restriction on having only sums of unrepeated momenta or difference of only pairs of momenta does not seem to allow a workaround.

For example ATLAS in 1209.0753 uses DeltaPhi(P_gamma, P_miss), the difference in azimuthal angle between a photon transverse momentum and the missing transverse momentum. I have the info on the missing momentum in terms of two invisible particles, but I cannot use it, or its complement, it seems.

Cheers
Gabriele

Question information

Language:
English Edit question
Status:
Solved
For:
MadAnalysis 5 Edit question
Assignee:
Benjamin Fuks Edit question
Last query:
2013-11-29
Last reply:
2013-11-29
Gabriele Ferretti (ferretti-o) said : #2

Hi,
I realize this is low priority, but I was wondering if there is any plan to add more observables to the list in table 7, 8 and 9 of the manual 1206.1599.

Cheers
Gabriele

Benjamin Fuks (fuks) said : #4

Hi Gabriele,

Sorry for having missed that message. This variable is now added from v1.1.8. It is called MT_MET. See e.g. the question #233529.

Cheers,

Benjamin

Markus Ebert (markus-ebert) said : #6

Hi Benjamin,

I don't see how MT_MET helps to implement a cut on the angle (deltaPhi) between a particle and the missing transverse momentum.
Is there a way to do this without using the expert mode?

Cheers,
Markus

Benjamin Fuks (fuks) said : #7

Hi Markus,

Indeed it does not. You can use instead the keyword invisible and the standard ma5 functions for that.

Cheers,

Benjamin

Markus Ebert (markus-ebert) said : #8

The problem is that I am working with PGS results, where the invisible particles are not listed anymore and just occur as missing energy.

Gabriele Ferretti (ferretti-o) said : #9

Hi everyone,
Right Markus, that's the problem I am having too.

"invisible" works in parton mode but in reconstructed mode ma5 does not recognize the type 6 momentum in the LHCO output which denotes the missing pt.
I am using Delphes, not PGS but the problem is the same.

Cheers

Gabriele

Benjamin Fuks (fuks) said : #10

Hi everyone,

Sorry, I said "invisible" but the correct keyword is "met". For instance,
  plot dPHI(e-[1] met)
will do the required job.

Cheers,

Benjamin

Thanks Benjamin!
It works like a charm!
Have a nice weekend.
Gabriele

PS: Be prepared because I am planning to invite you for a short visit in
Goteborg next spring...
I hope you can make it, let me know if there is a good period.

On 11/28/2013 6:11 PM, Benjamin Fuks wrote:
> Your question #234834 on MadAnalysis 5 changed:
> https://answers.launchpad.net/madanalysis5/+question/234834
>
> Benjamin Fuks proposed the following answer:
> Hi everyone,
>
> Sorry, I said "invisible" but the correct keyword is "met". For instance,
> plot dPHI(e-[1] met)
> will do the required job.
>
> Cheers,
>
> Benjamin
>