# Presentation: 848874

## Beate Heinemann 
University of Liverpool

For the CDF collaboration

**University of Liverpool**
**For the CDF collaboration**

- EPS 2003, Aachen, 17.-23.7.2003

**Physics Beyond the Standard Model with Photonic Final States at CDF**

## Exotics Searches with Photons 

- 10-6 events expected!

**Exotics Searches with Photons **
**in CDF Run II**

** ****CDF at Run 2**
** ****Search for ****LED**** ****in**** ****Di-Photon****  Production**
** ****Search for ****Anomalous**** ****Photon****+Lepton**** Production**
** ****Search for ****GMSB**** ****with ****Di-Photon+**
**  ****Search for Photon**** + ****Heavy Flavour**** ****Production**
** ****Search for ****LED**** with ****Photon+**
**Anomalous Couplings: ****W/Z+****Photon**

- The CDF event: ee

- Naho Tanimoto@EW meeting

##   The CDF 2 Detector

**  ****The CDF 2 Detector**

**New for Run 2**
- Tracking System
- Silicon Vertex detector (SVX II)
- Intermediate silicon layers (ISL)
- Central Outer tracker (COT)
- Scintillating tile forward calorimeter
- Intermediate muon detectors
- Time-Of-Flight system
- Front-end electronics (132 ns)
- Trigger System (pipelined)
- DAQ system

**Retained from Run 1**
- Solenoidal magnet (1.4 Tesla)
- Central Calorimeters
- Central Muon Detectors

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##  CDF Run 2 Luminosity

** ****CDF Run 2 Luminosity**

- Integrated
- Luminosity
- pb-1

- Data
- Recording
- Efficiency

**~****280 pb****-1**** delivered**

**~****220 pb****-1**** recorded**

- 90% efficiency

- ~ commissioning

**physics**

- 07/2003

- Physics Analyses use about 80 pb-1 recorded up to Jan 2003
- (about twice as much good quality data on tape since)
- Data taking efficiency about 90% now

**Run 1b (1994-1996)**

- 08/2001

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## Identification of Photon Signals in CDF

_**Signals**_
_**Backgrounds**_

****

****

****

******0**

_**Photon candidates**_**:****  Isolated electromagnetic showers in the calorimeter, with no charged tracks pointing at the calorimeter cluster**

-   Two techniques for
-    determination of photon signals;
-    1. _EM Shower width (shape):_
-        using Shower Max. Detector
-    2. _Probability of Conversion:_
-        using pre-radiator  hits
-  Statistical background subtraction

**Identification of Photon Signals in CDF**

**Central EM Calorimeter**

**Shower Maximum Detector**

**Pre-shower Detector**

|  | - | -Jet | Jet-jet |
| --- | --- | --- | --- |
| CPR | 29±23% | 40±28% | 30±23% |

**e.g.  for diphoton candidates,**
**S/B result using CPR method is..**

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## Di-Photon Mass Spectrum

** **_**Search Selection:**_** **
-      **2 photons with E****t****>13 GeV, cosmic and     ****	****beam-halo rejection cuts**
** **_**Main backgrounds**__:_
-     **fakes from photon-jet and jet-jet: ****	****determined from data!**
** **_**Results:**__ _**1365(95)events for E****t****>13(25) GeV**** **

**M********=168GeV**

**        **_**For **__**M > 150 GeV**_
**Expected background:   3.3  **
**Observed: ****	****              2.0**

**       **_**Run I Results (LED Search)**_
**observed: 287(192) CC(CP) events **
**                  **
**95% C.L. Limits on eff. string scale:**
**using a maximum likelihood fit method**

**NO excess observed @  High **
**invariant mass, **_**good agreement **_
_**b/w Run II Data and expectation**_

**        **_**For **__**M**__****__** > 150 GeV**_
**Expected background: 4.5 ******** 0.6  **
**Observed: ****	****             5**

**95 % C.L. M****S ****> 899 / 815 GeV**
** ****K****LED ****= 1.0  (******** = -1/+1, Hewett) **

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## +Jets and  +Leptons Search

** **_**Search for **__****__** + X; X=jet(s)**_** **
**To search for anomalous production of quarks and gluons, look in anomalous N****jet**** production in ********data**

** **_**Search Selection:**_**  ****Diphoton+extra lepton(s)**
** **_**Main backgrounds**__:_** **
**   ****W/Z+********, fake ********, Z********,e(********)********+jet**_** **_

**No event found**

**Good agreement of  Run II data with expectation..**

**Result consistent with SM**

** **_**Search for **__****__** + X; X=lepton(s)**_** **

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## Search GMSB for +      

**                  **

** **_**Search Selection:**_** **
-      **2 central photons w/ Et>13(25)**
**     ****Cosmic/beam halo clean-up**
** **_**Main backgrounds**__:_ **(see plot)**_ _
**    ****QCD diphoton, **
-     **jet mis-ID, W+photon (lost track)**
** **_**Results:**_
**    ****1392(97)events for Et>13(25)**** **

**   **_**For Missing Et>25GeV**_
**Expected background:   ****2********2**** **
**Observed: ****	****               ****2**

** ****Gravitino is the LSP**
** ****NLSP: Neutralino ********1******** ********G**
** **
** ****Experimental Signature: ********+E****T**

**Missing Et Spectrum**

****** ****Set cross section limit**_** **_

**SUSY would show up as an excess of events with large Missing Energy**

- Run 1: eeEt

- pp →X → GG + X

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## Search GMSB for +      (II)

**Set the lower mass limit on the lightest**
**chargino in GMSB:**_** **_
**           **_**M**__**c**__**>113 GeV @ 95% C.L.**_

**Acceptance**

**Events Expected**

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## B Motivation

- Topological search sensitive to “new physics”
- Require photon and b-jet
- Can look for , e, , jets in addition
- Search originally motivated by Run 1 eeEt event
- E.g in **MSSM**: chargino + neutralino +i02
- 02->01, +1->01tb
- 	 2b-jets, photon, lepton, missing Et

- Mass at sec. Vertex:
- separate b-, c- and
- light quarks

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## Photon + b-jet: A first look

- Cross Sections:
- b-: 40.6±19.4(stat.) ± 7.6(syst.) pb,   LO: 68.6 pb
- c-: 486 ± 153(stat.) ± 88 (syst.) pb,   LO: 368.4 pb
- Data agree with LO QCD predictions
- More excl. Searches and Limits on New Physics soon

- Mass @ sec. vertex

- Missing Et /GeV

- B-jet-γ-Mass/GeV

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## Search for New Physics in +

-  - **one ******** with E****T ****> 47 GeV and |********|<1**
** ****- Missing E****T ****> 42 GeV**
** ****- No jets with E****T ****> 10 GeV**
** ****- No tracks with p****T ****> 5 GeV**** **** **

**Results: **_**No excess was found**_
**Expected background: 18.0 ******** 2.1  **
**Observed: ****	****             17**

| Cosmic ray muons | 3.9  1.0 |
| --- | --- |
| Z  + | 4.8  0.5 |
| W  e | 7.3  1.7 |
| QCD diphotons | 1.1  0.4 |
| W ()  | 0.9  0.3 |

**Main backgrounds: **

**(84 pb****-1 ****)**** **

**Randall-Sundrum**

_**Search for New Physics in**__** **____**+**_

_**95% C.L. upper limit on**_** **
**(**_**accep.**_** x  **_**eff.**_** x **_**cross-section**_**) of**
**121 fb was set**

**Run I limit: M****S****>0.58 TeV**

**ADD**

**Extra Dimensions**

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## New Physics in W Production?

-  Sensitive to TGC (): e.g. compositeness of W/Z
- Run I: excess at high Et: lepton Et>25 GeV, Met>25 GeV, photon Et>25 GeV

****

| lepton | Data | SM exp |
| --- | --- | --- |
| muon | 11 | 4.2 |
| electron | 5 | 3.4 |
| both | 16 | 7.6 |

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## W Production

|  | Data | BG | •BR(Wl) (pb) |
| --- | --- | --- | --- |
| e | 43 | 33% | 17.2±3.8stat±2.8sys±1.0lum |
|  | 38 | 29% | 19.8±4.5stat±2.4sys±1.2lum |

***W********* Production**

**s-channel diagram not present in SM**
**Signature: ****high p****T**** lepton(e********) ********, MET>25,  photon Et>7 GeV, ********R(********-l)>0.7**
** ****Results: **_**No excess was found**_
**   ****Data: ****	****                                 43(38)**
**   ****Signal MC+Background : 46.6 ******** 1.3 ******** 4.5**** **
**                                              ****(36.5 ******** 0.7 ******** 3.0)**** **

**... ****derived the  cross section for**
**Et(********)>7, ********R>0.7**

**Results consistent with SM**
_**SM: **__****__**•B(W**__****__** **__****__**l**__****__**) = 18.7 ± 1.3 pb**_

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## Z Production

***Z********* Production**

**Signature: ****two high p****T**** lepton(e********) ******** **
**   ****(********R(********-l)>0.7) **
** ****Results: **_**No excess was found**_
**   ****Data: ****	****                   11(14)**
**   ****Signal MC+BGD : 10.8 ******** 0.9 ******** 0.6**** **
**                                ****(12.4 ******** 1.2 ******** 0.7)**

|  | Data | BG | •B(Zll) (pb) |
| --- | --- | --- | --- |
| e | 11 | 4.6% | 5.5±1.7stat±0.6sys±0.3lum |
|  | 14 | 4.0% | 6.0±1.6stat±0.7sys±0.4lum |

**Results consistent with SM **
_**SM: **__****__**•B(Z**__****__****__**ll**__****__**) = 5.4 ± 0.4 pb**_

**3-body mass**

**Photon Et**

**cross-section for Et(********)>7, ********R>0.7**

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## Conclusions

- CDF is taking high quality data in Run 2
- Run 2 statistics about twice of Run 1
- Covering broad range for photon searches:
- Model independent, LED, SUSY,...
- No evidence of new physics found
- Nothing like run 1 event found yet
- ... but if mother nature gives it to us we will for sure find it!

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## Backup Slides

## Di-Photon Mass Spectrum

**Classic LHC higgs search channel**
**SM higgs cross section factor 100 too low for TeVatron, but e.g. boso-philic higgs**
**Model independent search for “bump” in di-photon mass spectrum**
**No Signal, limits soon**

**RUN 2**

** **_**Search Selection:**_** **
-      **2 central photons with Et>13(25)**
**     ****Cosmic and beam halo clean-up**
** **_**Results:**__ _**1365 events for Et>13 GeV**** **

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## Search for Excited Electrons

**Since cross-section depends on M****e***** & ****Λ****,  we obtain exclusion region using various values of M****e***** and ****Λ**

** ****Search for the production of excited or exotic electrons (e*) in :**
** ****resonance in e******** invariant mass in ee******** events:**** **
**select two high p****T**** electrons ******** one photon (Et>25 GeV)**** **
** ****0 event observed:**** ****set**** ****mass limit on e*****  ****for contact interaction  model:**** ****For M****e***** = ****Λ****,  the mass limit is**** ****785 GeV**

** ****M(e*)<785 GeV**

**Λ**** = Compositeness Scale**

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