Diphoton + MET Analysis Update

Bruce Schumm

UC Santa Cruz / SCIPP

3 April 2013 Editorial Board Meeting

03 April 2013 2

In January, we were preparing to unblind our two strong-production analyses

Many studies had been done and we were addressing finer points in assuring that backgrounds were understood

We were then asked to move to p1328

EGamma10NoTauLooseRef had been chosen for p1181 after substantial study

Studies needed to be redone for p1328; several questions raised that we have been exploring since then

This update will be solely on our MET studies & status since then.

03 April 2013 3

MET performance of new variables, vs. old: DATA

• Points are p1181 EGamma10NoTauLooseRef (prior chosen variable)

• LocHadTopo did not change between p1181 and p1328

Numbers of events in last two bins

Tight-tight (signal) sample, blinded for MET>100

03 April 2013 4

LocHadTopo

Others

p1328

p1181

MET performance of new variables, vs. old: MC• Gamma-gamma MC; 18 GeV filter

• Limited tails for LocHadTopo (more stats on way…)

03 April 2013 5

Control Samples: MC• Signal (gg,GG) is from gamma-gamma MC

• Control samples (QCDtg, QCDg) from gamma-jet MC

• Control photon in control sample NOT ISOLATED

Proposed nominal control sample

03 April 2013 6

Control Samples: MC

• EGamma10NoTauLoose in p1328

03 April 2013 7

Control Samples: MC

• LocHadTopo in p1328

03 April 2013 8

Control Samples: MC

• MetRefFinal in p1328

03 April 2013 9

Control Samples: DATA

• QCDg

• Significant change between p1181 and p1328

p1181

p1328

P1328 MetRefFinal

03 April 2013 10

Control Samples: DATA

• QCDtg

• Significant change between p1181 and p1328, although not as much as for QCDg

03 April 2013 11

Control Samples: DATA (shows higher MET)

• EGamma10NoTauLoose in p1328

Signal (blinded)

Good proxy for signal?

03 April 2013 12

Control Samples: DATA (shows higher MET)

• LocHadTopo in p1328

03 April 2013 13

Control Samples: DATA (shows higher MET)

• MetRefFinal in p1328

• Again QCDtg looks OK but QCDg not as good

03 April 2013 14

CONCLUSIONS/OUTLOOK FOR p1328

Hope to get more statistics for gamma-gamma MC by raising filtering thresholds; being generated now. But for now:

LocHadTopo• Has smallest tails for tight-tight sample• All control samples look very good (including high-statistics QCDg-noIso, which was used for 7 TeV)

MetRefFinal• Bigger tails for tight-tight sample• QCDtg-noIso and QCDg-iso control samples look OK

EGamma10NoTauLoose• Bigger tails• No acceptable control samples

03 April 2013 15

03 April 2013 16