# Presentation: 856278

## L2/Offline MET

**Pal Hidas**
**Shuichi Kunori**
**05-March-2002**

**PRS: Physics Reconstruction and Selection**
**HCAL/JetsMET group**

## SUSY: Probing Points

**(S.Abdullin)**

## Complex SUSY Channel- an example -

**  ****m ****0****  m ****1/2**
**(1425,312)**

**~40%**
** **
**~60%**

**M****h            ****116GeV**
**M****gluino****   804GeV**
**M****squark****  1500GeV**

**( a SUSY point from hep-ph/0105204)**

## qqH(120), Hinvisible

**Signal:   (********BR)    4300fb   ****(BR=1)**
**Background:**
**   ****QCD Zjj**
**   ****QCD Wjj    **
**   ****EW   Zjj**
**   ****EW   Wjj      **
**   ****NB:  tt is no more major background.**

**    **

**q**
**Invisible**
** ****(neutralinos)**
**  ****(gravitinos)**
**q**

**Event selection:**
**   ****2 FWD tag jets**
**        ****Et > 40GeV**
**        ****|********|>4.4,  ********1*************2****<0.0**
**        ****M(jj) > 1200GeV**
**Between 2 FWD jets  **
**        ****no jet**
**            ****Et>20GeV**
**        ****no lepton**
**            ****pt(m) > 5 GeV**
**            ****pt(e) > 10GeV**
**   ****MET>100GeV**
**   ****|********(jj)| < 1.0**

## Reconstruction and Selection

**MET Reconstruction**
**Vector sum of E****T**** in ECAL+HCAL towers**
**Threshold E****T****(tower)>0.5GeV**
**Energy scale correction  ****(not applied in this analysis)**
**Jet energy correction for found jets and “min-bias” correction for outside of the jets (cone).**
**Event Selection**
**Filter to remove abnormal events and/or channels**
- CMSIM120: large energy deposit in single readout
-  **Due to 1) wrong choice of a GEANT parameter for energy loss  and 2) memory collapse(?) in CMSIM**
**E****T****(1x1)/E****T****(3x3) > 0.9**
- Real detector:
**Due to hot/noisy channel (for example)**
**Topological cuts**
- Back to back jet veto for 1st & 2nd highest ET jets
**1)   no cut,   2) |********| > ********- 0.5**

## MET resolution

******, ******** excluded**

**QCD Bins (P****T****-hat)**

**  ******** ****< 5**

**reconstructed**

## MET Distributions

**SUSY**

**Invisible Higgs**

**MET**

**MET**

## QCD jets: MET RatesGenerated Particle Level

******, ********  excluded**

**       ******** ****< 5  ********, ********  excluded)**

**1Hz**

## QCD Jets:Heavy Flavor Contribution

**heavy flavor fraction**

**MET**

**Generated MET**

**P****T**** hat**

##  for MET > 50 GeV

**80 < PT < 120 GeV**

**380 < PT < 470 GeV**

**MET vs Jet2**

**Jet1 vs Jet2**

## JJ cuts and results

**                     ****- this -      - DZ -**
**Higgs          74.7           (96.7)  fb**
**QCD Zjj       48.0           (71.8)****QCD Wjj        ****job running**
**EW Zjj         12.8           (14.8)**
**EW Wjj          8.9           (9.9)**** **
**          ****(very preliminary)**

**Set upper limit  on **
*******BR(H********inv)**** **

**(A.Nikitenko & K.Mazumdar)**

## L2 without/with  cut

**1Hz**

**120 GeV**

**90 GeV**

**No ********(1,2) cut**

******(1,2) cut**

**~10 reduction in rate with ******** cut**

**MET Threshold**

**MET Threshold**

## L2 (no (1,2) cut)  vs L1

**MET HLT Threshold**

**MET L1 Threshold**

**1Hz**

**L2**

**L1**

## mSUGRA1

**mSUGRA1**

**1kHz**

**1Hz**

**Generated MET**

**Trigger rates with 95% efficiency**
**    ****as a fucc of generated MET**

## Invisible Higgs

**Trigger rates with 95% efficiency**
**    ****as a function of generated MET**

**Generated MET**

**1Hz**

**1kHz**

## Alternative HLT for Invisible Higgs

**(A.Nikitenko)**

## Summary

**L2 MET Thresholds for 1Hz are**
**120GeV without ********(1,2) cut**
**~90GeV with ********(1,2) cut**
**Need to implement MET energy scale correction with “jet correction”**
**Need to understand source of difference in L2 and L1 MET resolution.**
**Continue to look for algorithm to lower the MET threshold by**
**Additional topological cuts**
**Improving MET resolution**