# Presentation: 038206

**Non SUSY Searches at the Tevatron**
- Kaori Maeshima (Fermilab)
- For the D0 and CDF Collaborations

- Simona Rolli, Fermilab W&C seminar

## Search Strategies & This Talk Organization

- New Phenomena               Exp. Signatures

- But, all the analyses start with the experimetal observables, ‘final state signature’
**One type of signature can explore many different models**.

- In general, this talk is organized by the physics topics.
- With the exception of the high mass dilepton search (signature based approach).

- Searches are motivated by the  physics beyond the Standard model.
**One type of model (new particle) can predict many different signatures (decay modes).**

- (******e****** jets+ET, etc.)

- (Z’, SUSY, Extra Dimension, LQ, etc....)

- Simona Rolli, Fermilab W&C seminar

## New Phenomena          Exp. Signatures

**W’**
**Z’, Extra Dimensions, TC, etc...**
**Leptoquarks (LQ)**
**Technicolor (TC)**
**Extra Dimensions (ED)**
**monopole**
**compositeness**
**excited lelptons (e*)**
**fourth gen. quark, SUSY,etc.**
**Doubly Charged Higgs**

**e******
**high mass dilepton (ee, ********, ********)**
**eejj, ********jj, ********jj, lνjj, ννjj**
**Wbb, dilepton**
**dilepton, diphoton, Jets+ E****T**
**dedicated monopole search**
**dilepton, **
**e******** **
**long-lived parents of the Z boson**
**Same sign dilepton (ee, mm,em)**

- http://www-cdf.fnal.gov/physics/exotic/exotic.html
- http://www-d0.fnal.gov/Run2Physics/WWW/results/np.html

- (      Topics covered)

- Simona Rolli, Fermilab W&C seminar

## Run II Tevatron Performance

- Operating extremely well with recycler.
- highest Lum: 1.052 e32 cm-2sec-1,Jan,2005
- single store high :5.05 pb-1,  Jan,2005
- Analyses presented here are using  up to
-        ~ 345 pb-1 of data

- FY2002

- FY2002

- FY2003

- FY2003

- FY2004

- FY2004

**FY2005**

**FY2005**

***Highest  Energy Collider in Operation!***

**place to search for new physics**

**CDF**

**D0**

**P**

**P**

**√****s ******** 1.96 ****TeV**

**Int. Lum.**

**Peak Lum.**

- Simona Rolli, Fermilab W&C seminar

## W’: additional charged heavy vector boson
appears in theories based on the extension of the gauge group 
e.g. Left-right symmetric models: SU(2)R    WR
assume: the neutrino from W’ decay is light and stable.
signature: 
high pT electron + high ET

- appears in theories based on the extension of the gauge group
- e.g. Left-right symmetric models: SU(2)R    WR
- assume: the neutrino from W’ decay is light and stable.
- signature:
- high pT electron + high ET

**W’ search in e******** channel**

- MC only

- high pT electron + high ET

- (very recent result from run II.)

- W’**SM**

- Simona Rolli, Fermilab W&C seminar

## W’ search (cont.)

**W’ search (cont.)**

- highest MT event
- MT = 524 GeV/c2

- MT Distribution of Data

- Simona Rolli, Fermilab W&C seminar

## W’ search (cont.)

- No evidence of W’ existing.....
- set limits on W’ production rate
- use binned likelihood fitting method
- two types of systematics are examined as a function of MT :
- affect event rate (dominant: PDF, ~14% at MT= 850 GeV)
- affect the shape  (dominant: electron energy scale, ~16% at MT= 850 GeV)
- *B(W’    e) limit:  ~ 50 – 100 fb for M(W’) > 500 GeV/c2 at 95% CL.

- Limit: M(W’SM )> 842 GeV/c2

- Run I results (with the same assumptions):
- M(W’SM )>  754 GeV/c2

- (All the limits stated in this talk are at at 95% C.L.)

- W’SM

- Limit

- Simona Rolli, Fermilab W&C seminar

**Notes:**
W’ limits from runI:  CDF enu: 754 GeV (run I, 110 pb-1), munu:646 GeV (run Ib, 89pb-1)
Do:720 GeV (79 pb-1)  from enu GeV, also limits for the case N is heavy, decay to eqq, 650 – 720 GeV

## Searches in High Mass dileptons 

**ee**

****

- ∫Ldt = 200 pb-1

- ∫Ldt = 250 pb-1

-  Relatively ‘clean’ channel
-  Z0 peak as a calibration point
-  Many models to explore:
- Z’, TC, RS graviton, LED, compositeness, etc...

- QCD Bgd.

- Z’SM 600 GeV

- (Signature based approach)

- Simona Rolli, Fermilab W&C seminar

## Searches in high mass dileptons (cont.)

**ee**

**ee**
- both-forward

****

****

- both-central or
- central-forward

- Simona Rolli, Fermilab W&C seminar

## Mass Bump Search Strategies

- Perform general searches comparing data to expectation
- Determine spin dependent acceptance and .BR*
- Interpret the results according to many new models!
- Spin-0:   RPV sneutrinos
- Spin-1:   Z’SM, E6 Z’,  Little Higgs Z’, TC (****T, ****T)
- Spin-2:   RS graviton

- Z' occurs naturally in extensions of SM towards GUT scale, e.g. “E6” models
- M(Z')>570 GeV for E6 models (depends on exact model:
- 	 couplings to quarks and leptons)
- M(Z')>750 GeV for SM coupling
-     *(D0 M(Z**'**)>719 GeV, 122 pb-1)*

**X**

- * Though D0 has not calculated the spin dependent acceptances explicitly as CDF, the approaches are similar.

- Simona Rolli, Fermilab W&C seminar

## Spin-dependent Acceptance

**Spin-dependent ****Acceptance**

- The following plots show the efficiency times acceptance of detecting a particle decaying into a electron-positron pair as function of the mass. Since the spin of the particle changes the angular distribution of the decay particles we consider the possible spin of any new particle separately: spin-0 , spin-1 and spin-2.

- spin-0  	        spin-1  	                  spin-2

-        Angular distribution and therefore acceptance of decay product depends on the spin of the decaying particle.

**central-central electrons**
**central-forward electrons**
**above combined**

- central:  |****| <  1.1
- forward: 1.1 < |****| < 3.6

- Simona Rolli, Fermilab W&C seminar

## *B Limits  (ee and  channels combined)

- The following plots show the efficiency times acceptance of detecting a particle decaying into a electron-positron pair as function of the mass. Since the spin of the particle changes the angular distribution of the decay particles we consider the possible spin of any new particle separately: spin-0 , spin-1 and spin-2.

- spin-0  	        spin-1  	                  spin-2

- spin-0                            spin-1                              spin-2

*****Br limit: ~ 25 fb for all spins for the high mass region (Mll > 600 GeV)
- These limit curves can be compared with many models
- Individual channel limits are still very important - lepton universality ?

- Simona Rolli, Fermilab W&C seminar

## Spin-1, Z’ limits

**SM Couplings****    ee      ********    ee+********    ******
**      ****CDF :              ****750    735    815       394**
**      ****DØ:                 ****780    680**
**        ****E****6****  ****           Z****I****     Zχ      Zψ    Zη **
**      ****CDF:           ****610  670   690  715   ****(ee+********)**
**      ****DØ:             ****575  640   650  680****   (ee)**

- z’ mass limits (in GeV/c2)

- ∫Ldt = 200 pb-1

- ∫Ldt = 250 pb-1

**D0:  ee**

**CDF:  ******

**D0:  ******

- Simona Rolli, Fermilab W&C seminar

## Several extensions of the SM model (GUTS, Technicolor, Compositeness, RPV-SUSY)
assume an additional symmetry between leptons and quarks

- Several extensions of the SM model (GUTS, Technicolor, Compositeness, RPV-SUSY)
- assume an additional symmetry between leptons and quarks

- 30% increase in
- cross section at RunII

**Leptoquarks (direct searches)**

- Carry both lepton (L) and baryon (B) numbers
- Couple to quark and lepton of the same generation

- At the TeVatron they are
- pair produced

- Their decay is controlled
- by  = BR (LQlq )

- Experimental signature:
- _high P__T__ isolated lepton(s)_
- _and/or E__T __+ 2 jets_

- 3 generations

- Simona Rolli, Fermilab W&C seminar

## 1st  and 2nd generation LQ

- channels: eejj, ejj, (jj)

- for =1,
- D0: Run I + II, MLQ > 256 GeV/c2
- CDF: Run II, MLQ > 235 GeV/c2

- channels: jj, jj, jj

- for =1,
- D0: Run I, MLQ > 200 GeV/c2
- CDF: Run II, MLQ > 224 GeV/c2

- Simona Rolli, Fermilab W&C seminar

**Notes:**
nnjj channel, combined (CDF), 85pb-1 data analysed by D0 for nnjj.  Not combined for this plot.

##   3rd generation LQ

- channel: ******l********h**jj (one leptonic, one hadronic decayed ****’s)

- for =1,
- CDF: Run II, MLQ > 129 GeV/c2

**final state: ********bb****, same as the**
**RPV Stop search**** signature**
**(see details ******** SUSY talk)**

- expect 4.8 + 0.7 events,
- observed 5 events

- Simona Rolli, Fermilab W&C seminar

**Notes:**
nnjj channel, combined (CDF), 85pb-1 data analysed by D0 for nnjj.  Not combined for this plot.

## Technicolor

- Can search for Technicolor in many signatures
- This search explores same signature as SM Higgs (lνbq)

- ˉ

**,****c**

- Simona Rolli, Fermilab W&C seminar

## Technicolor

- note: We had mass bounds on this channel in Run I.
- Run II cross section limit is better than Run I.
- The theoretical prediction was revised downwards.

- From the spin-1 dilepton result,
- mass bounds are also obtained for
******T** and** ********T** for different MT.
- MT is a parameter in the Straw-man
- TC model which affects the production
- cross section and the decay rates.

- MT	   mass limit (GeV/c2)
- 500	   320
- 400	   315
- 300	   310
- 200	   225

- Simona Rolli, Fermilab W&C seminar

## Extra Dimensions (ED)

- Alternatives to SUSY for solving the hierarchy problem (MEW << MPlank ?)
- Focus on:
- Models with n extra spatial dimensions
- _Large ED (ADD):_
- n>0 (n>2) compactified
- M2PL~RnMsn+2, Ms: string scale
- _TeV-1 ED (DDG):_
- n>=1 (n=1)
- Mc: compactification scale
- _Warped ED (RS):_
- n=1, highly curved
- k/MPl, k: curvature scale

- Arkani-Hamed, Dimopoulos, Dvali
- Phys Lett B429 (98)

- Dienes, Dudas, Gherghetta
- Nucl Phys B537 (99)

- Randall, Sundrum
- Phys Rev Lett 83 (99)

- ee
****
****

- jet(s)+ET
-  + ET

- G

- G

- g,q

- g,q

- g,q

- g,q

- f

- f

- jet

- exchange

- emission

- Simona Rolli, Fermilab W&C seminar

## LED with dilepton & 

-  ηG = F/MS4
-  F is a model dependent dimensionless parameter ~ 1:
-  GRW:       F = 1
-  HLZ:        F = log(Ms2/M2), n =2
-                   F = 2/(n-2), n > 2
-  Hewett:   F = 2 **λ**/π, **λ** = ±1
- Ms is the UV cutoff = MPL(4+n dim)

- Gravity effect parametrized by G

- ee, **γγ**
- invariant
- mass

- Functions of M & cos*
- determined by theory

- scatter.
- angle

- DØ Search Strategy:
- Combine dielectron and diphoton to diEM signature
- Fit distribution of M vs cos* of Data – SM
- Extract ηG from the fit
- Translate ηG into Ms limit

- Search for enhanced dilepton production

**LED with dilepton & ******

- Simona Rolli, Fermilab W&C seminar

## LED with ee &

- Translate G95% limits to 95% CL l*ower *limits on Planck scale MS,  in TeV, using different formalisms for F

| GRW | HLZ for n =  | Hewett |
| --- | --- | --- |
|  |   2      3      4      5      6      7  | λ = +1/-1 |
| 1.36 | 1.56  1.61  1.36 1.23  1.14  1.08  | 1.22/1.10 |
| 1.43 | 1.67  1.70  1.43 1.29  1.20 1.14  | 1.28/NA |

- DØ RunII

- DØ RunI + Run II

- *NLO k=1.3 scale applied to signal MC

**LED with ee &******

- Data

- QCD

- SM
- prediction

- Signal
- prediction

- Data vs MC

- Simona Rolli, Fermilab W&C seminar

## LED with 

- pT > 15 GeV for both muon objects
- Isolated tracks
- M(mumu) > 50 GeV
- Cosmics removed
- Weighted average PT correction

- Observed  events ~ 17,000 events

- No deviation from SM in data

| GRW | HLZ for n =  | Hewett |
| --- | --- | --- |
|  |   2       3       4      5       6       7  | λ = +1/-1 |
| 1.09 | 1.00  1.29  1.09 0.98  0.91  0.86 | 0.97/0.95 |

- DØ ∫Ldt = 250 pb-1

**LED with ******

- Lower limits on the fundamental Plank scale, MS in TeV

- Simona Rolli, Fermilab W&C seminar

## Randall-Sundrum Graviton (ee + + )

- Scale of physical phenomena on the TeV-brane is specified by the exponential warp factor:
-            = Mple-kRc
-      ~ TeV if kRc ~11-12.

- Randall-Sundrum gravitons are excluded by these data in the plane of coupling (k/MPl) versus effective graviton mass. E.g. for k/M_Pl=0.05 masses less than 500 GeV are ruled out at 95% C.L..

- for k/M_Pl=0.05 masses less than 500 GeV
- are ruled out at 95% C.L..

- Scale of physical phenomena on the TeV-brane is specified by the exponential warp factor:
-            = Mple-kRc

-  ~ TeV if kRc ~11-12.

- Clean experimental signature. Low backgrounds

- gg initiated process

- Dilepton Channel

- K/Mpl 0.1	620
- 	0.05	470
- 	0.02	310
- 	0.01	200

- Add Run I limits?!

-  **ll** has largest acceptance at low mass
**  ******** **has largest acceptance at high mass
-  BR(**G****→******) =  2 * BR(**G→ee**)

****

- Simona Rolli, Fermilab W&C seminar

## Dirac Monopoles

- Signature
- Large pulses in Time of Flight (TOF)
- Large ionization in drift chamber (COT)
- No curvature in r-phi
- Curvature in r-z (not used in analysis)
- Developed a dedicated trigger for Monopoles

- Simona Rolli, Fermilab W&C seminar

## Monopole Search Results

- Drell-Yan like cross section

- Simona Rolli, Fermilab W&C seminar

## Summary and Conclusions

- Many searches for new physics are underway in D0 and CDF
- Presented: some of the more recent preliminary results
**Surpassed the sensitivity and results of Run I**
**Limits shown either exceed any published results of direct searches or are the first limits ever!**
- Lots more data to analyse

- Many new exciting results from Tevatron experiments  and more coming soon!

- .BR upper and mass lower limits on various new physics models @ 95 % using 200 pb-1 of CDF II high mass *ee*+****+**** data

- Simona Rolli, Fermilab W&C seminar

## CDF & DZero Experiments

- Extended spatial e, μ coverage
- New plug calorimeter improves also MET measurement
- Improved MET triggers
- Added triggers to identify  leptons at early stage

- New silicon and fiber tracker
- Solenoid (2 Tesla)
- Upgrade of muon system
- Upgrade of Trigger/DAQ

**CDF & DZero Experiments**

- Simona Rolli, Fermilab W&C seminar

## LQ search in jj

- 124 events observed

- Signature: Large MET and 2 jets

- ’ =BR(LQq) = 1

- Expected =11814

- Sample Composition:
-   W/Z + jets
-   top
-   QCD fakes

- M(LQ) > 117 GeV/c2 @ 95 % C.L.

- Expected =41.54.2

- 44 events observed

- M(LQ) > 120 GeV/c2 @ 95 % C.L.

- for Q(normalization scale) = m(LQ)

- Simona Rolli, Fermilab W&C seminar

## LED with Monojet + MET

- Search for Real Graviton Emission

- DØ ∫Ldt = 85 pb-1

- Data Selection:
- MET > 150 GeV,
- Jet1 > 150 GeV
- Jet2 < 50 (reduce ISR, FSR)
- ΔΦJ-MET  > 30o (reduce chance that  MET comes from jet mismeasurement)
- Irreducible Background:
- Z-> **νν** + 1 or 2 jets (60% of total bckg.)

- Limit on Planck Scale Md

- After all selection cuts
- observe 63, expect 100 with ~60% uncertainty

- q

- q

- g

- Gkk

- Gkk

- _

- g

- g

- g

- heavy G escapes to extra D
-  large MET
- recoil jet very energetic

**Analysis sensitive to jet **
**energy scale (JES) uncertainty.**

**Data versus SM**** **

- LEP

**LED with Monojet + MET**

- Simona Rolli, Fermilab W&C seminar