MadGraph5_aMC@NLO

Matching between generated and reconstructed masses

Asked by Miqueias

Hello dears!
I'm a new MadGraph user and for learn how this tool works I'm carefully checking its output and variables that I reconstructed with an own code (like the Z and Higgs mass). I did a comparison between the values of masses generated by MadGraph and the values of mass reconstructed by my code here. And sometimes the values doesn't match. The values of generated masses vary around the nominal particle mass, but very close. While that the reconstructed masses not always match with this generated masses and in those cases there is big difference between them. I know that it is normal difference between the reconstructed masses and the nominal particle mass because in my process I want Higgs on and off-shell. I don't understand why this happens only with the reconstructed masses and not also with the generated masses. Could somebody explain me this behavior of MadGraph?

*(What I say as generated mass is the value coming from Particle_M command)

Question information

Language:
English Edit question
Status:
Solved
For:
MadGraph5_aMC@NLO Edit question
Assignee:
Hua-Sheng Shao Edit question
Solved by:
Miqueias
Solved:
Last query:
Last reply:
Revision history for this message
Miqueias (connect-miqueias) said : 		#1

Just for possible future help... about this question... there is no problem with MadGraph. The difference is normal and is associated with the purity of the method to ressonances reconstruction (the which is not 100%). I made a counting to verify how much the generated and reconstructed events are equal (using a histogram to respect the minimum capacity of resolution of the detector CMS - 2/3GeV) and the purity was found around 96% (that is a good value).