Snapshot of Photon + MET Trigger Studies

Bruce Schumm, SCIPP/UCSCSUSY-EtMiss Subgroup Meeting24 November 2010

Significant Transition: MGM to GGM

Tevatron analysis based on “Snowmass Points and Slopes” trajectory that is essentially Minimal Gauge Mediation (MGM)

MGM ties strong (gluino) and EW (neutralino) partner scales together, and leads to very massive gluino

Tevatron analyses exploited weak production (lot of data at low energy); sets limits on neutralino mass

MGM not particularly well motivated look at Generalized Gauge Mediation (GGM) which decouples strong, EW scales

Re-cast in terms of limits in Mg-M plane for each of three possible neutralino species: Bino-, Wino-, Higgsino-like

Bino-Like Neutralino Grid

For Bino-like neutralino, two photons + MET is most promisingbut lose coverage if hadronic activity is required (jets, HT, etc.)

No visible jet activity when

Mg ~ M

Desecrated plot thanks to Shih/Ruderman, ArXiv 0911.4130

D0 Limit

pT of photonsM bino = 150 – 580 GeV

M gluino = 600GeV ( = 0.26pb )

M bino = 200 GeV

M gluino=400–700GeV (=6–0.07 pb)

• BR doesn’t change ~ 80%

• pT of photons ~ similar

• BR changes vs. M bino: • 90% (M bino = 150GeV)• 65% (M bino = 580GeV)

• pT of photons!

Photon pT can be soft for M

small

Production cross-section (7TeV)Wino - like Neutralino: |M2|<< and |M2| < |M1|

Natural for photon+lepton channelNot shown: Higgsino, which has no photonic decay

TRIGGERS?

Back to Bino-like case…

Summary for grid points we have generated so far.

Results are out of 1000 events

Some inefficiency for M = Mg – 30 (haven’t yet explored)

What about ET dependence?

Close to 2g20_loose would be close to knee (remember that current limit is below this, at 150 GeV)

Tentative Conclusions for Bino-Like Case

• We are probably OK for 2g20_loose, and perhaps even 2g25_loose (need to run through M = 150 case)

• Tight electron trigger 90% efficient For e control sample (background estimation),

gXX_loose eXX_tightwhere XX is value of 2g trigger above, should be

fine.

What about a quick peek at non-pointing photons?

GMSB2 sample: c ~ 10s of cm

What about non-photon triggers? Looking into it…

Summary and Conclusions

• Pending a look at M = 150 GeV, proposed 2011 triggers seem workable for Bino case

• Other cases (Wino, Higgsino) being looked into

• Non-pointing photons don’t seem to be captured with photon triggers; what about others? Looking into that also.

Sorry – that’s all folks…