# Presentation: 838029

## Bill Orejudos
CDF Collaboration
Lawrence Berkeley National Laboratory
ICHEP 2002
July 24-31, 2002

**Bill Orejudos**
**CDF Collaboration**
**Lawrence Berkeley National Laboratory**
**ICHEP 2002**
**July 24-31, 2002**

## Outline

- Tevatron, CDF, D0 upgrades
- Searches
- new gauge bosons
- technicolor, compositeness, topcolor
- long-lived heavy charged particles
- new physics with photons
- Large Extra Dimensions
- Supersymmetry: see talk by V. Zutshi
- Conclusion

## The Tevatron

- First phase of Run II  (Run IIa)
- started spring 2001

## CDF Upgrade

- CTC replaced by
- COT

- SVX replaced
- layer of silicon
- added to beampipe

- Intermediate Silicon
- Layers (ISL) added

- Time-of-Flight
- (TOF) added

- Upgrade will
- allow operation
- at high luminosity
- and extend physics
- capabilities

- New Electronics,
- Trigger, DAQ

- End Plug Calorimeters
- upgraded, extended to

- Muon System upgraded

- New Forward
- Detectors

- Plug Shower Max added

## D0 Upgrade

## Remove dilepton events

- Require lepton to be central and isolated

- Require at least one jet to be tagged as a b-jet

- New CDF Run I analysis
- looks for

## Excluded:

## Events from jet triggers selected

- Jet *E*T > (115,85,50,30) GeV

-     Dijet mass distribution shows no
-     evidence of an excess

- Excluded:

## Drell-Yan Production

- Dilepton final state can
- be used in searches for:

- - quark-lepton compositeness

- - large extra dimensions

- - technicolor

- This would be modified by the presence of
- some sort of new physics – could exchange
- a new gauge boson, Kaluza-Klein (KK) tower, etc

- Could also have new diagrams leading to dilepton
- final states, e.g. 2 gluons coupling to KK tower.

## Selection of Dilepton Events

- Events selected with
- Leptons required to:
- Be oppositely charged
- Have a high transverse momentum
- Be isolated
- Originate from single vertex
- Background low at high lepton inv. mass:

- CDF Run I Dilepton mass distribution

- No deviation
- from SM

- 110 pb-1

## Results and Run II Reach  

***Results and Run II Reach***

## Z peaks, Run II data

- Dimuon Mass

- Analyses to look for an
- excess in the high mass
- region in progress by both
- CDF and D0

## Drell-Yan searches can also be used to look for evidence of

- technicolor and quark-lepton compositeness. D0 Run I limits:

- (other decays
- suppressed)

- Quark compositeness searched for in dijets. D0 Run I limits:

- compositeness scale

## Technicolor searched for in other channels. CDF  limits:

- Missing *E*T > 20 GeV

- 2 jets, *E*T > 15 GeV, one b-tagged

- 160-240 GeV/*c*2 at Run IIa

- 2 jets, *E*T > 20 GeV, one b-tagged

- 2,3 jets with *E*T>15 GeV, one b-tagged
- No other jets with *E*T>7 GeV, no leptons
- Missing *E*T > 40 GeV

- 850 GeV/*c*2 at Run IIa

## Topcolor

- Missing *E*T>20 GeV
- 4 jets, *E*T>15 GeV
- 4th jet: *E*T>8 GeV if
- one other jet b-tagged

- 106 pb-1

## CHAMPS

- Charged Massive Particles,
- long-lived enough to leave
- detector

- Heavy, slow moving particle
- Large time-of-flight (TOF)
- Large dE/dx

- CDF Run I analysis:
- High *p*T trk w/ large dE/dx
- Use high *p*T muon trigger

## CHAMPS at Run II

- Sensitive region of momentum
- Spectrum for 100 GeV stau using
- dE/dx

- Stable stau pair
- production

## CDF Run II CHAMP Analysis

- Track must have large *p*T,
- be isolated, have large TOF

- Signal Sample: *p*T> 40 GeV/c
- Control Sample: *p*T >20,<40 GeV/c
- Control1: *p*T >20, <30 GeV/c
- Control2: *p*T >30, <40 GeV/c

- Expected Background:

- Number predicted, observed
- in Control2

- Value of *TOF*diff cut

## Photon Physics at Run II

- Searches for new physics
- are in progress...

## New Physics with Photons

-  Photons isolated
-  Bckgnd: Jets faking photons

- CDF has searched for new physics
- in the Run I diphoton sample:

- No excess in diphoton sample.

- Search for bosophilic higgs

- Selecting W/Z:

- OR

- OR

***New Physics with Photons***

- No excess in
- Diphoton-W/Z sample

## Inclusive Photon+Lepton Search

- Main Backgrounds:

- CDF has performed a model independent search at Run I for new
- physics that gives leptons, photons, missing *E*T in final state

## Large Extra Dimensions

- D0 has searched for LED in
- diphoton/dielectron sample

- 2 EM objects
*E*T> 45 GeV for each
- Missing *E*T<25 GeV
- 1282 events in sample
- Bckgnd: Drell-Yan,

- Invariant mass, angular dist.
- of EM objects considered

- No deviation from SM,
- Limit on eff. string scale *M*S

*M*S > 1.1 (1.0) TeV/*c*2 for
- const. (dest.) interference
- between Kaluza-Klein and
- SM contributions

## Graviton emission:

## D0 search with jets and missing ET

*E*T (jet1) > 150 GeV
*E*T (jet2) < 50 GeV
- Missing *E*T > 150 GeV
- Missing *E*T, jet2 > 15o  apart
- No isolated muons

- LED search*,** G*KK*g* final state

## Limits from Run II

- D0 has repeated LED search in
- diphoton/dielectron final state

- 2 EM objects
*E*T> 25 GeV for each
- Missing *E*T<30 GeV

*M*S > 0.82 TeV/*c*2 for const. interference between Kaluza-Klein and SM contributions

- No deviation from SM

- D0 leptoquark search
- 2 EM clusters w/ *E*T> 25 GeV
- >1 jet w/ *E*T>20 GeV
- Z veto

*M*LQ > 113 GeV/*c*2

- Main bckgnd: Drell-Yan, fakes

- No excess above SM

- Still need more data to improve on Run I results

## Conclusion

- D0 and CDF have searched for new physics with many different signatures
- Dileptons
- Dijets
- Diphotons
- Jets with a heavy flavor tag
- Jets and missing *E*T
- Photon and missing *E*T
- Inclusive photons+leptons
- Large dE/dx and large time-of-flight
- Many different models have been explored
- No evidence yet for new physics
- Run II has started, searches are in progress!