Snapshot of Photon + MET Trigger Studies

Bruce Schumm, SCIPP/UCSCSUSY Trigger Meeting14 December 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

Tevatron 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 for two-photon trigger

What about ET dependence?

Close to 2g20_loose would be close to knee (remember that current limit is just below this, at ~175 GeV)

Tentative Conclusions for Bino-Like Case

• We are probably OK for 2g20_loose, and perhaps even 2g25_loose

• As far as we know now, control samples will be accumulated naturally with 2gXX_loose triggers.

• Alternatively, gXX_loose would probably be fine for XX < 70 GeV (both signal and control)

• Loose (as opposed to tight) is essential for control samples (have not explored developing control sample with pre-scaled trigger but am somewhat skeptical)

What about a quick peek at non-pointing photons?

GMSB2 sample: c ~ 10s of cm

What about non-photon triggers? Looking into it…

Triggering on GMSB with Jet Triggers (2009 study) Assume pointing/non-pointing have same jet character

Highlighted trigger is 1J60 2J20; perhaps similar to proposed 3J50?

WINO-Like Case

HIGGSINO-Like Case

• Natural signature is photon + lepton

• +e: 2gXX_loose or 1gXX_loose should work as for Bino-like case

• +: Did not look into muon trigger threshold; single muon trigger may be adequate for thresholds less than ~50 GeV

• trigger best; case not made

• No photons in the limit of pure Higgsino

• Admixture would give photon + jets

• Would have some sensitivity with 1gXX trigger

• jet trigger ideal; case not made

Summary and Conclusions

BINO-Like

• 2g25_loose and/or 1g70_loose look OK.

• Not easy to make independent case for 2g triggers, but precedent makes us a little uneasy to give them up.

• Non-pointing covered by jet triggers?

WINO-Like

• 1g or 2g trigger probably fine for +e signature; probably less efficient for +.

• Pure muon trigger might provide additional coverage

• clearly ideal, but no work done to make case

HIGGSINO Admixture

• jets ideal, but work to make case not done

Sorry – that’s all folks…