Control_Regions.htmlControl Regions: What Are They?

[ChrisVer]

What are control regions? Is it a different name for "signal region"?
If yes I don't really understand what they mean with the following:

In order to ensure that simulation is properly modeling the data, several control regions which are orthogonal to the signal regions are investigated.

http://www-cdf.fnal.gov/physics/ewk/wwllll/

 

[Orodruin]

No, as your quote states, they are orthogonal to the signal regions. It means that you expect no signal there and so you can try to use them to see if you understand your background.

 

[ChrisVer]

Strange, then why would a Drell-Yan control region require low missing ET and dilepton mass around the Z boson's one?

 

[mfb]

It is one of the control regions for WW production. With low missing ET and a mass around the Z peak the contribution from WW is negligible, and you can check selection efficiencies.