ZZ Update

1
ZZ Update

• Answers to your questions
• 1) The electrons are ordered in Pt.
• 1 is first leading and 2 is second leading
  and so on
• 2) I did not use the charge selection as it
  seemed quite bad first time I did try it.
• In AANTuple there is a variable Trk_qoverP which
  I use to check the charge.
• 3) I am not sure about the tracks and for the
  moment I am looking at jets. Also, checked the
  topo cluster

2
In case the jet candidate is within dR lt 0.2 from
a the truth unfound electron, I sort all the
possible combinations between all 3 electrons and
the truth unfound electron and find the best
combination closer to the Z mass (91.2 GeV)
3
In case the jet candidate is within dR lt 0.2 from
the truth unfound electron, I sort all the
possible combinations between all 3 electrons and
the jet candidate and find the best combination
closer to the Z mass (91.2 GeV)
4
In case the jet candidate is within dR lt 0.2 from
the unfound truth electronif Z_Best is 13 so
Z_second 2jetcandidate if Z_Best is 23 so
Z_second 1jetcandidate
5
ZBest vs Second
6
Here no truth information at alli.e. remove the
dR lt 0.2 from the unfound truth electron
7
Here no truth information at alli.e. remove the
dR lt 0.2 from the unfound truth electron
Also, I tried a cut on the signal ZBest within 20
GeV from the Z mass (91.2 GeV) And the second Z
peak (Z_second) should be within 40 GeV from the
Z mass (91.2 GeV) I got 53 signal efficiency I
am thinking about a way to avoid the truth.
8
In The Zbb sample

• I do not have enough data on Zbb sample
• Out of 36150 events of Zbb -gt 3l there are 921
  that passes my kinematics cuts.
• I had to scale the data by a factor of 182
• In the following plots I did not

9
In case the jet candidate is within dR lt 0.2 from
the unfound truth electron, I sort all the
possible combinations between all 3 electrons and
the jet candidate and find the best combination
closer to the Z mass (91.2 GeV)
10
ZBest vs Z_second
11

• The second peak is a very good handle to lower
  the background. I am looking for a way to use the
  jet candidate without the dR from the truth
  unfound electron.
• I did check the ratio of the Pt of the jet
  candidate and the track associated to it and it
  was way off.
• I was thinking to take the ones that have a ratio
  1
• ( I might be doing wrong )
• Do you have any suggestions ?
• My main concern now is how to use this cut in an
  efficient way without relying on the truth.
• I hope that I was clear on all these slides and I
  hope to hear your comment at your earliest
  convenience.
• I will also try to learn how to do analysis on
  the AODs .