Removing further ZZ background

As I showed before the cut on the energy of the Z can eliminate a fraction of the ZZ background (see plot in previous post below). I am trying now other cuts that could improve further the removal of ZZ background.

I am applying the same cuts up to now:

• M_Z between 88 GeV and 94 GeV
• E_Z between 100 GeV and 103 GeV

The plot below shows the dijet mass (jets were reclustered into 2 jets after the muons coming from a Z boson are removed). One can see that the signal and the background are quite distinct.

Applying a cut on the dijet mass, Mjj .gt. 96 GeV, the ZZ background was further reduced.