Open ytatus94 opened 7 years ago
Hi Yu-Ting,
Definite post to Higgsino-28. Also, you may want to post your MadGraph cards: run card, param card, proc card, and MadGraphControl setup (if relevant) just in case people spot any obvious problems there.
Cheers,
-Mike
Hi Yu-Ting,
On 06/21/2017 08:11 AM, Yu-Ting Shen wrote: Hi Mike and Jesse, In the simplified model, I didn't see the Z and W decays, but I did see N2 --> N1 + Z (BR=0.9) N2 --> C1+ + W- (BR=0.05) N2 --> C1- + W+ (BR=0.05) C1+ --> N1 + W+ (BR=1.0)
MadGraph and MadSpin ignore these BR's, unfortunately. Pythia would follow them if we allowed the EWKinos to decay in Pythia, but we don't do that.
There are two lines about the Z and W
Does it mean that the Z and W decays are specified in other file?
Z and W decays are done in MadSpin:
https://svnweb.cern.ch/trac/atlasoff/browser/Generators/MC15JobOptions/trunk/common/MadGraph/MadGraphControl_SimplifiedModel_higgsino.py7
See lines 115 and 174, for example.
The model gets the BR's completely wrong, so we rescale the sigmaBR for these samples during the analysis according to the NLO cross section, the simplified model BR of N2-> Z N1 (100% in this case), and then the Z*->ll BR. This is all described in the internal note, so you can look there for some of the details and exact numbers. There's also a lot of discussion on this in various (closed) Jira threads, you can do some archaeology there if you want more context.
Unfortunately I'll be away for the next week and a half, so if you have other urgent questions on this, I hope Jesse and others will be able to help. Using Jira for these questions may enable more people to jump in with answers, so don't be afraid to update HIGGSINO-28 with any questions you might have.
Cheers,
-Mike