# Presentation: 073272

**Run II Searches for Supersymmetry**
**Dave Toback**
**Texas A&M University**

## Structure

**SUSY searches at the Tevatron focus  on mSUGRA/MSSM, GMSB and RPV**** **
**Present every Run II result from first 200 pb****-1**** using **_**C**__**O**__**L**__**O**__**R**_** code**
**Minor excesses or interesting events which I’ll be keeping my eye on as the dataset doubles, quadruples or goes up by an order of magnitude**
**New world’s best limit**
**Hot off the presses result**

## Overview of Results

**CHAMP Searches**
**Jets + Met Searches**
**Multi-lepton Searches**
**Diphoton+Met Searches**

## CHArged Massive Stable Particles

**Final cut here**

**Track P****T****>18 GeV**
**L = 53/pb**

**Cut on TOF (nsec)**

**Search for long-lived charged particles using Time-of-Flight system**
**Particles behave like slow, but high P****T**** muons **
**2.9****±****0.3(stat)****±****3.1(sys) expected from instrumental mis-measurement**** **
**Observe 7**
**Small excess...Lots more data already taken and being analyzed**

## CHAMPS: Results and Limits

**Excluded by ALEPH**

**Lots of theories predict CHAMPS**
**Stop **
**Staus**
**Charginos**
**Sleptons**
**New limits on Stop at 107 GeV which is the new world limit**
**Nice complement to the Run I decay based searches for Stop**

**L = 53/pb**

## Search for New Physics in Jets+Met

**Search for New Physics in Jets+Met**

**Direct searches for Squarks and Gluinos in jets+Met final state**
**Two searches at the Tevatron with preliminary results**
**Light-quark jets+Met**
**Heavy flavor jets+Met**
**Extend sensitivity beyond LEPs kinematic reach**

## Light-quark jets+Met

**Squarks and Gluinos produce acoplanar jets +Met**
**Require:**
**At least two large jets **
**Total H****T****>275 GeV**
**Met>175**
**2.67±0.95 expected**
**4 events observed in the data**

**L = 85/pb**

**Background predictions dominated by ****Electroweak**** not ****QCD**

**Final Cut here**

**Z ******** ******** ****+ 2jets**
**W ******** ******** ****+ jet**

## The interesting event on the tail

**Kinematics:**
**2 big jets: E****T****=289 GeV and 117 GeV **
**2 little jets: E****T****=14 GeV and 11 GeV **
**Met=381 GeV**
**Expect 1 event above 300 GeV; ~1⁄4 above 350 GeV**** **
**Background dominated by Z****→********jets**
**Doesn’t particularly look like signal or background**

## Limits on Squarks & Gluinos

**Set limits in mSUGRA scenario **
**New gluino mass limit at 333 GeV (for a squark mass of 292 GeV) extends previous world’s best**

**mSUGRA model with M****0**** = 25 GeV/c****2****, A****0****=0, tan B = 3, ********<0, varying M****1⁄2**

**Excluded by CDF Run I**

**L = 85/pb**

## Search for Sbottom Squarks

**Search for Sbottom Squarks**

**L = 156/pb**

**Gluinos decay into Sbottom quarks and produce *****b*****-jets and Met**
**Two separate analyses: **
_**Single-tag + Met:**_** ****	**** ****Back=16.4±3.6   Observe 21 **
_**Double-tag + Met:**_** **
**	****Back=2.6±0.7   **
**  ****Observe 4**
**Backgrounds dominated by Top quark pairs**
**~1/2 event expected above 125, 2 observed**

**Final Cut: Met>80 GeV**

## Limits on Sbottoms 

**Limits on Sbottoms **

**L = 156/pb**

**CDF Run I**

**Gluino production allows significant extension of the best limits at high mass Sbottom and low mass neutralinos**

******0**** Mass (GeV)   **

**Sbottom Mass (GeV)**

**New limits are not sensitive to when Sbottom mass is close to the LSP mass. **
**LEP sensitivity is still best there**

**Sbottom Mass (GeV)**

**Gluino Mass (GeV)**

**CDF Run I**

**CDF Run II**

## Multi-lepton searches

**Multi-lepton final states have been a staple of SUSY searches for many years**
**Low mass indirect searches in B****S****→******
**High mass resonance searches for RPV Sneutrinos**
**Chargino/Neutralino Pair-production and decay**

## BS→

**B****S****→**********

**L = 171/pb**

**4******** **
**Mass Window**

***Accepted for publication in PRL**

**Indirect search for SUSY via loop diagrams which affect the branching ratio by one to three orders of magnitude.**** **
**Search in 4******** mass window around known world average and optimize using topology cuts**
**1.1****±****0.3 events expected**
**1 Event observed**

## Limits and SUSY Interpretation

**Br****SM****=3.5x10****-9 **
**Previous best limit at 2.0x10****-6**** (CDF Run 1)**
**New Limit: **
**Br(B****S****→********=7.5x10****-7**** ****	****→World’s best**
**No official model interpretation**

***Blow up of example from previous talk by A. Belyaev**

## High Mass Resonance Searches

**Tevatron searches for resonances in ee and ******** have been done for many years for Z’, E6, Higgs, Technicolor etc. (See talks by M. Gold/M. Karagoz)**
**New interpretation in terms of RPV Sneutrino production and decay.**
**First limits for large masses**

**L = 200/pb**

## Chargino/Neutralino Pair Production

**Chargino/Neutralino Pair Production**

**Chargino/Neutralino pair production can produce three leptons +Met**
**Since the end of Run I, LEP has significantly improved the limits**
**Three new results in this mode:**
**Like- sign muons**
**Two electrons + lepton**
**Electron + Muon + lepton**

**Gold plated signature of mSUGRA for low tanB**

## Like-Sign Muons

**In 147/pb:**
**Predict 0.13 ****±**** 0.06**
**1 Observed**

**Increase acceptance by only requiring two out of three leptons**
**Reduce background by requiring them to be like-sign**
**P****T1****>11 GeV**
**P****T2****>5 GeV**
**Met>15 GeV **
**M********<80 GeV**

**DØ**

## Electron+Muon+lepton

**P****T**** of Third Track>3 GeV**

**L = 158/pb**

**Predict 0.5****±****0.2 **
**0 observed**

**Require:**
**Electron>12 GeV**
**Muon>8 GeV**
**Met>15**** **
**Look for a third isolated track: ****e, ******** or ******

## Two-electrons+lepton

**Two-electrons+lepton**

**Two high P****T**** isolated *****e*****’s, a 3****rd**** lepton (high P****T**** isolated track) and Met**

**Met **x **P****T****(3****rd**** Track) >250 GeV****2**

**Electron E****T ****= 33 GeV and 26 GeV**
**Track P****T**** = 8.6 GeV **
**Met = 52.1 GeV**
**Background dominated by WW, but is likely W******** where the photon converted**

## Combine results to set limits

**Combine results to set limits**

**All three searches are optimized for the region above the LEP limits**
**Combined result produces the most stringent limits from the Tevatron to date**
**Significant improvement over Run I results, but no extension of the exclusion region from LEP (yet)**

## GMSB Searches in Two Photons+Met

**GMSB Searches in Two Photons+Met**

**In Run I CDF found an ee********+Met candidate event**
**Extensive searches for similar events at LEP and the Tevatron produced no other interesting events**** **
**New results from CDF and DØ which optimize for GMBS ************→ ********G scenario**

**~**

**CDF Run I**** **

**~**

## GMSB +Met

**DØ (185/pb)**

**E****T****>13 GeV, Met>45 GeV**
**Predict 0.6****±****0.5**
**0 Observed**

**E****T****>20 GeV, Met>40 GeV**
**Predict 2.5****±****0.5**
**1 Observed**

**CDF (202/pb)**

## Limits on GMSB with → G

**L = 202/pb**

**CDF (202/pb)**

**DØ (185/pb)**

**New world best limit!**
******>78.8 TeV**
**Chargino mass>192 GeV**
**Neutralino Mass>105 GeV**

**~**

**~**

**LEP Limit**

## Interesting Event

**Interesting Event**

**Event is in data later than previous result, but is interesting nonetheless**
**E****T**** of photons: 69 & 27 GeV**
**E****T**** of electron 24 GeV**
**All well measured &                                                     ****	****Well separated**
**Met=63 GeV**
**W********? **
**Cousin of CDF ee********Met?**
**If all “ee********Met” favored SUSY parameter space is nearly excluded, then what is it?**

**DØ**
**e********Met Candidate**

## Conclusions

**It’s an exciting time to be at the Tevatron as it is the high energy frontier for the next *****N***** years.**
**Preliminary results on the first 200 pb****-1**** are starting to come rapid-fire with first publications already submitted & accepted**
**Many of these results are the world’s most sensitive**
**Results on the next 200 pb****-1**** are in the pipeline and the detectors and the Tevatron continue to improve and provide new sensitivity**
**Lots of interesting things to keep our eyes on in the coming year...**