Ryan J. Hooper -- DPF, May 24-28, 2002 1 Searching For Large Extra Dimensions at D Extra...

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Ryan J. Hooper -- DPF, May 24-28, 2002

Searching For Searching For Large Extra Dimensions at Large Extra Dimensions at

• Extra dimensionsExtra dimensions

• Overview of Run 1 resultsOverview of Run 1 results

• Run 2 expectationsRun 2 expectations

• Current Run 2 dataCurrent Run 2 data

– The diEM channelThe diEM channel

– The diThe di channel channel

• SummarySummary

Ryan J. Hooper (University of Notre Dame)Ryan J. Hooper (University of Notre Dame)

On behalf of the DOn behalf of the D Collaboration Collaboration

• String Theory yearns for n=6,7 extra dimensionsString Theory yearns for n=6,7 extra dimensions– Compactified with radius R ~ 10Compactified with radius R ~ 10 -32-32mm

– Astrophysical and table top experiments: Astrophysical and table top experiments:

– Ruled out n=1 and put significant Ruled out n=1 and put significant

constraints on n=2constraints on n=2

– Placed limits on R < 0.15mmPlaced limits on R < 0.15mm

• ““Large” Extra Dimensions (LED)Large” Extra Dimensions (LED)– Arkani-Hamed, Dimopoulos, Dvali (ADD) hep-th/9809124Arkani-Hamed, Dimopoulos, Dvali (ADD) hep-th/9809124

– Graviton is only particle that propagates in extra dimensionsGraviton is only particle that propagates in extra dimensions

– Effective Planck scale (MEffective Planck scale (MSS) down to TeV ranges) down to TeV ranges

– A solution to the hierarchy problemA solution to the hierarchy problem

– Kaluza-Klein modes of the graviton (GKaluza-Klein modes of the graviton (GKKKK) can enhance effects at colliders) can enhance effects at colliders

Extra DimensionsExtra Dimensions

nnSPl RMM 22

• At DAt D we look for direct G we look for direct GKKKK production production– Strong n dependenceStrong n dependence

• 1/(MS)n+2

– Gluon or vector boson + EGluon or vector boson + ETT

– EETT from graviton from graviton

escaping detectionescaping detection

• We look at virtual GWe look at virtual GKKKK

exchange as wellexchange as well– Weaker n dependence Weaker n dependence

– F/MF/MSS44

– F = 1 (GRZ)F = 1 (GRZ)

= log(M= log(MSS22/M/M22) for n=2, 2/(n-2) n>2 (HLZ)) for n=2, 2/(n-2) n>2 (HLZ)

= 2= 2//; ; = ±1 (Hewett) = ±1 (Hewett) USED FOR THIS TALK!USED FOR THIS TALK!

– Two lepton or two vector boson final statesTwo lepton or two vector boson final states

Extra Dimensions at DExtra Dimensions at D

DD Run 1: Direct G Run 1: Direct GKKKK Search Search• P-pbar P-pbar gluon + G gluon + GKKKK

• Final state jet + EFinal state jet + ETT

• Recent monojet resultRecent monojet result– ~79pb~79pb-1-1 of Run 1 data of Run 1 data

– EETT > 150 GeV > 150 GeV

– Leading Jet: ELeading Jet: ETT > 150 GeV > 150 GeV

– ||– Gives complementary limitGives complementary limit

to LEP results for n > 4to LEP results for n > 4

• Final states are dileptons or diphotonsFinal states are dileptons or diphotons

• In Run 1 looked at dielectrons + diphotonsIn Run 1 looked at dielectrons + diphotons– For better sensitivity For better sensitivity

combine e and combine e and to form “diEM” to form “diEM”

• Invariant mass vs. |cos(Invariant mass vs. |cos()|)|• LEDs at high mass LEDs at high mass

and low |cos(and low |cos()|)|

• ResultsResults– 127pb127pb-1-1 of data of data

– EETT > 45 GeV > 45 GeV

– ||| < 2.5| < 2.5

– EETT < 25 GeV < 25 GeV

• LEP: MLEP: MSS > ~ 0.5-1.2 TeV > ~ 0.5-1.2 TeV

DD Run 1: Virtual G Run 1: Virtual GKKKK Search Search

MMSS > 1.1 TeV > 1.1 TeV

for for

MMSS > 1.0 TeV > 1.0 TeV

for for

q,g q,g

DD Run 2 Expectations Run 2 Expectations• Run 1: 0.13fb-1

• In Run 2• CM energy 1.96 TeV vs. 1.8 TeV in Run 1

• Run 2a: 2fb-1 doubling MS sensitivities over Run 1

• Run 2b: 15fb-1 tripling MS sensitivities over Run 1

• Upgraded DD detector

• Our current Run 2 LED analysis follows the Run 1 virtual GKK analysis previously mentioned

• Also add the dimuon channel

DD Run 2: DiEM Zs Run 2: DiEM Zs» The Z is a good place to “calibrate” high PT objects

» Using ~10pb-1 of data

» We see Z to diEM

» Cuts:» Standard DStandard D EM ID EM ID

» EETT > 20 GeV > 20 GeV

» EETT < 30 GeV < 30 GeV

» ||| < 1.1 or | < 1.1 or

1.5 < |1.5 < || < 2.5| < 2.5

Central + End Cap

Central + Central

DD Run 2: LEDs DiEM Channel Run 2: LEDs DiEM Channel We see 2 high mass eventsWe see 2 high mass events

Monte Carlo Data

D Run 2 Preliminary

» Highest mass diEM candidate

No extra dimensions yet…but let’s not forget the electron’s heavier No extra dimensions yet…but let’s not forget the electron’s heavier brother!brother!

DD Run 2: DiEM Channel Run 2: DiEM Channel

D Run 2 Preliminary

M(diEM) = 376 GeV; cos* = 0.79; MET = 8.2 GeV;

EM2EM1

ET = 109.7 GeV = -2.10 = 2.19No track match

ET = 115.4 GeV = 0.10 = 5.27No track match

DD Run 2: Di Run 2: Di Resonances Resonances» Once again lets use well known physics to “calibrate”

» ~10pb-1 of data» Cuts:

» DD Muon ID

» Both muons || < 1.6

» Pt tracks > 2.5 GeV

» For Z plot:

Track Pt > 15 GeV

D Run 2 Preliminary

Green Histograms = Opposite sign muons

Blue Histograms = Same sign muons

Upsilon

• We see a few high mass eventsDD Run 2: LEDs Di Run 2: LEDs Di Channel Channel

D Run 2 Preliminary

Monte Carlo Data

SummarySummary• Extra dimensions can bring the effective Planck Extra dimensions can bring the effective Planck

scale down to TeV energies scale down to TeV energies • DD in Run 1: in Run 1:

• Direct GDirect GKKKK production results complementary to LEP production results complementary to LEP limits for n > 4limits for n > 4

• Virtual GVirtual GKKKK exchange limits of M exchange limits of MSS > 1.1 TeV for > 1.1 TeV for = +1 = +1

• and Mand MSS > 1.0 TeV for > 1.0 TeV for = -1= -1

• DD in Run 2: in Run 2:• With 2fbWith 2fb-1-1, sensitivity to M, sensitivity to MSS should double vs. Run 1 should double vs. Run 1

• Virtual GVirtual GKKKK exchange in diEM and di exchange in diEM and di

• We currently have J/We currently have J/, Upsilon and Z resonances, Upsilon and Z resonances• See some higher mass events See some higher mass events

• Should have first physics results by ICHEPShould have first physics results by ICHEP

Ryan J. Hooper -- DPF, May 24-28, 2002 1 Searching For Large Extra Dimensions at D Extra...

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