1. Search For New Physics at the TeVatron
Jean-François Grivaz
LAL-Orsay
J.-F. Grivaz
Euro-GDR 25-November-2004

2. The Tevatron at Run II New Main Injector + Recycler Higher energy
Chicago 
Tevatron
Main Injector
& Recycler DØ
CDF
p source
New Main Injector
+ Recycler
Higher energy
(1.96 TeV vs 1.8 TeV)
=> Higher cross sections
(~30% for the top)
Higher antiproton intensity
6x6  36x36 bunches
(3.5 s  396 ns)
antiproton “recycler”
=> Higher luminosity
J.-F. Grivaz
Euro-GDR 25-November-2004

3. Luminosity performance
Peak luminosity:
cm-2 s-1
Weekly delivered:
pb-1
Data taking efficiency: %
Physics quality data:
up to 350 pb-1
analyzed as of ICHEP04
1032
J.-F. Grivaz
Euro-GDR 25-November-2004

4. Searches for New Phenomena
Supersymmetry: (m)SUGRA, GMSB
Extra Dimensions: large, warped
Extended Gauge Theories: Z’
Higgs bosons: SUSY, SM
In back-up slides:
RPV, leptoquarks, excited leptons, doubly-charged Higgses
Not covered :
TeV–1 ED, Technicolor, Little Higgs
but same signatures as e.g., LED, SM-Higgs, RS-gravitons
Real exotics (e.g. monopoles)
J.-F. Grivaz
Euro-GDR 25-November-2004

5. Supersymmetry
J.-F. Grivaz
Euro-GDR 25-November-2004

6. (m)SUGRA m0 m1/2 tan() A0 sign()
Two main search streams at the Tevatron:
Squarks and gluinos  multijets + missing ET
large production cross sections
large experimental backgrounds
Electroweak gauginos with leptonic decays (Trileptons)
low production cross sections
typically low leptonic branching ratios
clean experimental signature
J.-F. Grivaz
Euro-GDR 25-November-2004

7. Trileptons (I) Arise from chargino-neutralino associated production
“Golden” SUSY signature but:
- low cross sections ( BR)
- soft leptons
- taus (at large tan)
Needs large integrated luminosity
Combine various final states
(Also decays via W/Z exchange)
DØ analysis based on 147  249 pb1
Combines eel, el, l and same sign dimuon final states
Addresses “just beyond LEP” mSUGRA with low mass sleptons
J.-F. Grivaz
Euro-GDR 25-November-2004

8. Trileptons (II) Two isolated (rather soft) e or 
Require some Missing ET
 channel-dependent cuts (e.g. anti Z)
Two same sign muons, or
An isolated third track (no e or  ID)
Main backgrounds: WW, WZ, W, a bit of bb
Altogether: 3 events observed vs 2.9  0.8 expected
J.-F. Grivaz
Euro-GDR 25-November-2004

9. Trileptons (III) Substantial improvement wrt Run I:
m()  97 GeV for m(slepton)  m()
Should soon probe virgin mSUGRA territory
J.-F. Grivaz
Euro-GDR 25-November-2004

10. Stop and sbottom
CDF has searched for charged massive particles in 53 pb1
appear as slow moving (TOF) high pT muons
result interpreted for (meta)stable stop
 m(stop) 108 GeV (isolated) or 95 GeV (non-isolated)
CDF has searched for sbottoms
in gluino decays (156 pb1)
assumes sb1 much lighter than
all other squarks (large tan)
gluino  sb1 b
 4 b-jets + Missing ET
for gluino pairs
the selection requires at least
one b-tag, no isolated lepton
With 2 b-tags: 4 vs 2.6  0.7 expected
J.-F. Grivaz
Euro-GDR 25-November-2004

11. “minimum sq-mass line”
Generic squarks (I)
Strong production of:
sq-sqbar
sq-sq
sq-gl
gl-gl
In 85 pb1, DØ has searched
along the
“minimum sq-mass line”
of mSUGRA:
very low m0 (25 GeV),
(tan = 3, A0 = 0,   0),
scan over m1/2
 Mostly sq-sqbar with sq  q   Acoplanar jets + Missing ET
J.-F. Grivaz
Euro-GDR 25-November-2004

12. Generic squarks (II) Main selection cuts: at least two high pT jets
QCD
Main selection cuts:
at least two high pT jets
isolated lepton veto
Missing ET should not be
along or opposite to a jet
Sum of jet pT  275 GeV
Missing ET  175 GeV
Main backgrounds left:
(Z  ) + jets
(W ) + jets
QCD negligible
4 events selected vs
/1.5
expected
J.-F. Grivaz
Euro-GDR 25-November-2004

13. Generic squarks (III) Slight improvement over CDF-Run I
along that “minimum sq-mass line”:
(msq  292 GeV and mgl  333 GeV)
How relevant are the Tevatron
results on squarks and gluinos ?
LEP slepton and chargino limits  much tighter constraints
on m0 and m1/2 within mSUGRA (or even MSSM with unification)
The Tevatron should consider models with smaller M3/M2 ratios:
not unnatural in GUTs (e.g. M3/M2 ~ 1 if SUSY breaking by a 75)
or in some string inspired models
J.-F. Grivaz
Euro-GDR 25-November-2004

14.  Inclusive search for   Missing ET
GMSB with  NLSP (I)
Remember the CDF
ee + Missing ET event ?…
 + gravitino
 Inclusive search for   Missing ET
by both CDF / DØ
Photon = electron without track
Photon ET  13 / 20 GeV
Missing ET > 45 / 40 GeV
Mild topological cuts
Main backgrounds:
EM-jets (or real QCD photons)
+ fake Missing ET
electron + photon
+ real Missing ET
All determined from the data
CDF : 0 vs 0.3  0.1 expected
DØ : 2 vs 3.7  0.6 expected
J.-F. Grivaz
Euro-GDR 25-November-2004

15. GMSB with  NLSP (II) Interpretation within mGMSB 263 pb-1 with: N = 1
Mmessenger = 2,
  0,
tan = 15 (aka “Snowmass slope”)
Signal dominated by
chargino-neutralino production
263 pb-1
World best limit:
m  108 GeV (DØ)
(Also 93 GeV (CDF))
J.-F. Grivaz
Euro-GDR 25-November-2004

16. “Superjets” ? CDF @ Run I observed an excess of W + 2/3 jet events
with  1 jet “double-tagged”
(Secondary vertex + Soft lepton)
13 vs 4.4  0.6 expected
An interpretation in terms of
light sbottom + RPV ()
has been suggested (not by CDF)
DØ has searched for such an anomaly in 150 pb-1 of Run II data
and did not find any.
Let’s wait and see what CDF will find…
J.-F. Grivaz
Euro-GDR 25-November-2004

17. Bs   In SM, tiny BR ~ 3.5 109 (and 25 times smaller for Bd)
But in SUSY, a (tan)6 factor could lead to an enhancement
by as much as three orders of magnitude
Select dimuons originating from displaced vertices, and look inside a mass window:
BR limits (95% CL):
(DØ 240pb-1) and (CDF 171 pb-1)
Close to getting relevant
J.-F. Grivaz
Euro-GDR 25-November-2004

18. Extra Dimensions
J.-F. Grivaz
Euro-GDR 25-November-2004

19. Models of Extra Dimensions
Two classes of models considered:
ADD
2 to 7 large (sub mm) EDs
gravity propagates
freely in the bulk
KK excitations
cannot be resolved RS
one 5th (infinite) ED
with warped geometry
gravity is localized
on a brane other than the SM
have spacings of order TeV
J.-F. Grivaz
Euro-GDR 25-November-2004

20. Large Extra Dimensions
Two main search streams at the TeVatron:
Real graviton emission
Apparent energy-momentum
non-conservation in 3D-space
 “Monojets”
Direct sensitivity to the
fundamental Planck scale MD
GKK g q
Virtual graviton exchange
Modifies SM cross sections
Sensitivity to the theory cutoff MS
(MS expected to be  MD) V
GKK f
J.-F. Grivaz
Euro-GDR 25-November-2004

21. Monojets DØ search in 85 pb-1: Main selection cuts:
one high pT jet ( 150 GeV)
(soft jets from ISR are allowed)
isolated lepton veto
Missing ET away from all jets
Missing ET  150 GeV
QCD
Main background: (Z ) +jet
QCD is negligible
63 events selected
/-32 expected
Large error from Jet Energy Scale
(Updated result coming soon)
J.-F. Grivaz
Euro-GDR 25-November-2004

22. High pT dileptons & diphotons
DØ search in 200 pb-1 combines ee and  to maximize the sensitivity
Fit of Data to SM+QCD+LED(MS)
World tightest limits:
MS > 1.36 TeV
MS >1.43 TeV I
in the GRW formalism
Also 1.1 TeV:
from CDF in dielectrons with 200 pb-1
from DØ in dimuons with 250 pb-1
J.-F. Grivaz
Euro-GDR 25-November-2004

23. Randall – Sundrum gravitons
Here too, most of the sensitivity is in diphotons (BR = 2ee)
DØ uses the same
ee +  data set as
for the LED search
300 GeV RS-graviton
DØ Run II Preliminary
Two model parameters:
Mass and coupling (/MPl)
For /MPl = 0.1: M  785 GeV
Also 690 GeV from CDF in diphotons with 345 pb-1
J.-F. Grivaz
Euro-GDR 25-November-2004

24. Z’
J.-F. Grivaz
Euro-GDR 25-November-2004

25. Z’ in dielectrons
Now select only electron pairs (much reduced QCD background)
600 GeV Z’
DØ Run II Preliminary
For an SM-like Z’: M  780 GeV
Limits for SM-like Z’
and various E6 models
Also M > 750 GeV from CDF (200 pb-1)
J.-F. Grivaz
Euro-GDR 25-November-2004

26. Z’ in dimuons
Dimuons vs. dielectrons: lower background but worse resolution
For an SM-like Z’: M  735 GeV
Z’ limits in
various E6 models
Also M  680 GeV from DØ (250 pb–1)
Combining ee and : M (SM-like Z’)  815 GeV (CDF)
J.-F. Grivaz
Euro-GDR 25-November-2004

27. Z’ in  CDF in 195 pb-1 4 events (eh,h,hh) vs 2.8  0.5 expected
J.-F. Grivaz
Euro-GDR 25-November-2004

28. Higgs bosons
J.-F. Grivaz
Euro-GDR 25-November-2004

29. SUSY-Higgs @ large tan
Hbb coupling enhanced
DØ search for  3b jets (130 pb-1)
J.-F. Grivaz
Euro-GDR 25-November-2004

30. SM Higgs boson searches
LEP indirect: MH < 260 GeV
LEP direct: MH > 114 GeV Hint at 115 GeV
MH < 130 GeV: Hbb
gg H bb hopeless (H  maybe)
H(W  l) and H(Z  ll/): best processes
Hbb OK for large tan
Htt maybe
MH >150 GeV: H WW*
gg H (W  l)(W* l): best process
Also (H WW*)(W l / Z ll)
J.-F. Grivaz
Euro-GDR 25-November-2004

31. High mass: HWW
DØ search in the ee, e and  + Missing ET final states
The WW background is reduced
using the spin correlations:
smaller ll angle in the Higgs signal
(200 pb–1)
(147 – 177 pb–1)
2 ee events vs 2.7  0.4 expected
2 e events vs 3.1  0.3 expected
5  events vs 5.3  0.6 expected
J.-F. Grivaz
Euro-GDR 25-November-2004

32. Low mass: (Wl)(Hbb)
CDF search in 162 pb–1: e/ + Missing ET + 2jets ( 1 b-tag)
Similar DØ search
(174 pb–1 - e only)
with 2 b-tags
Still a long way
to go…
J.-F. Grivaz
Euro-GDR 25-November-2004

33. Are we going there ? LHC Now Updated signal and background
cross sections
Full detector simulation
+ established analysis techniques
+ “reasonable extrapolations”
+ Signal shape (vs. mass window)
(but no systematics…)
LHC
Now
If we are lucky: 3s evidence
If not…: 95% CL exclusion
of the MSSM range
J.-F. Grivaz
Euro-GDR 25-November-2004

34. Final remarks The Higgs is not the whole story…
With a data sample at least 20 to 40 times larger than at Run I,
collected at higher energy with improved detectors,
there is a lot of beautiful (but difficult) physics to be done:
W and top masses, top properties, single top production
B physics: Bs mixing, rare Bs decays, Bs and Lb lifetimes
Exploration of new territory (SUSY, LED…): we may be lucky…
already well underway
interaction with theorists welcome !
With a steadily improving collider performance
there are still a number of years and fb–1 ahead of us
for frontier physics at the Tevatron.
J.-F. Grivaz
Euro-GDR 25-November-2004

35. Back-up Slides
J.-F. Grivaz
Euro-GDR 25-November-2004

36. The CDF and DØ upgrades New silicon and drift chamber
Upgraded calorimeter (plug)
and muon system
New DAQ and new trigger,
(displaced track trigger)
New tracking: silicon and
fibers in 2T magnetic field
Upgraded muon system
New DAQ and new trigger
(commissioning displaced track)
… and new software (C++, OO)
J.-F. Grivaz
Euro-GDR 25-November-2004

37. The Run II Menu With 2 fb-1: Top mass to  3 GeV W mass to  30 MeV
Bs mixing to 20 ps-1
Exclude mH = 115 GeV
CDF/D0
2 fb-1goal!
And much more…
High pT jets
LED to 2 TeV
SUSY
And beyond:
J.-F. Grivaz
Euro-GDR 25-November-2004

38. RPV with ijkLiLjLk coupling (I)
DØ has searched for multilpeton final states arising from
SUSY particle pair production with
R-parity violating decays of two neutralino LSP’s
in the regime where  is small enough so that only the LSP has
an RPV decay, and large enough for its lifetime to be negligible.
The couplings considered were
121  eeee, eee or ee + 
122  , e or ee + 
Three isolated (rather soft) e or 
Require some Missing ET
 channel-dependent cuts (e.g. anti Z)
J.-F. Grivaz
Euro-GDR 25-November-2004

39. RPV with ijkLiLjLk coupling (II)
121: 0 vs 0.5  0.4 expected
(238 pb-1)
122: 2 vs 0.6  1.9 expected
(163 pb-1)
eee/
A search has also been performed
for the 133 coupling, in the eeX
final state, with   hadrons + 
(199 pb-1)
Resonant single slepton or sneutrino
production via a 211 RPV coupling
has also been investigated (154 pb-1)
m  200 GeV
J.-F. Grivaz
Euro-GDR 25-November-2004

40. Leptoquarks LQ  lq (BR = ) or LQ  q (BR = 1 – )
Pair produced  llqq, lqq or qq final states
2nd generation LQ in qq (CDF – 200 pb-1):
2 muons, 2 jets, Z-veto
M  241 GeV
2 events vs 3.2  1.2 expected
J.-F. Grivaz
Euro-GDR 25-November-2004

41. 1st generation Leptoquarks (I)
DØ analysis performed in the eeqq and eqq channels (175 pb-1)
2 electrons, 2 jets and Z-veto
1 electron, missing ET and W-veto
ST = ET(e1)+ET(e2)+ET(j1)+ET(j2)
ST = ET(e1)+MET+ET(j1)+ET(j2)
(After all other cuts)
(Before W-veto)
0 events vs 0.4  0.1 expected
2 events vs 4.7  0.9 expected
J.-F. Grivaz
Euro-GDR 25-November-2004

42. 1st generation Leptoquarks (II)
M  238 GeV ( = 1)
M  213 GeV ( = 0.5)
(DØ – 175 pb-1)
Also CDF with 200 pb-1:
M  230 GeV ( = 1)
M  176 GeV ( = 0.5 not combined)
J.-F. Grivaz
Euro-GDR 25-November-2004

43. Leptoquarks in the qq channel
Topology = Acoplanar jets + Missing ET
Large backgrounds from QCD multijets
and from SM processes (Z  jets)
Also DØ with 85 pb-1:
M  109 GeV
124 events vs 14.5 expected
J.-F. Grivaz
Euro-GDR 25-November-2004

44. Excited electrons CDF search in the ee final state (200 pb-1)
Z - veto
3 events vs 3.0  0.4 expected
(main background = Z)
J.-F. Grivaz
Euro-GDR 25-November-2004

45. Doubly-charged Higgs Bosons
Doubly charged Higgs (from Higgs triplets)
are predicted in, e.g., LR-symmetric models
CDF has searched for H
pair production in 240 pb-1
The signature is a pair of
same sign ee, e or 
0 ee events vs 0.6 expected
0 e events vs 0.4 0.2 expected
0  events vs 0.4 expected
Also DØ in  (113 pb-1):
M(HL) > 118 GeV
M(HR) > 98 GeV
J.-F. Grivaz
Euro-GDR 25-November-2004