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J.-F. GrivazSUSY-06 June 16, At the TeVatron : p-pbar collisions at 1.96 TeV c.o.m. energy Peak luminosity: > 1.7 E32 cm -2 s -1 Delivered: > 1.5 fb -1 In this talk: 0.2 to 1.1 fb -1 DØ: CDF: Main Injector Tevatron DØCDF Chicago p source Booster Unless there are good reasons, I’ll pick examples in either one. Still the energy frontier
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J.-F. Grivaz SUSY-06 June 16, 2006 1
Search for Physics Beyond the Standard Model
at the TeVatron
Jean-François Grivaz(LAL-Orsay)
for the CDF and DØ Collaborations
J.-F. Grivaz SUSY-06 June 16, 2006 2
Beyond the Standard Model:Enlarge the gauge group Z’, W’
(*) Alternative EWSB mechanisms (TC, little Higgs)(*) Relate quarks and leptons Leptoquarks
Extend Poincaré Supersymmetryand include gravitation (Supergravity)
Increase the number of dimensions(*) Repeat the history (compositeness)
(*) = Not covered today (in 30’)
The Standard Model:SU(3)c x SU(2)L x U(1)Y
The Higgs mechanismThree generations of quarks and leptonsThe Poincaré groupIn a 4-dimensional space-time
J.-F. Grivaz SUSY-06 June 16, 2006 3
At the TeVatron:p-pbar collisions at 1.96 TeV c.o.m. energyPeak luminosity: > 1.7 E32 cm-2s-1
Delivered: > 1.5 fb-1
In this talk: 0.2 to 1.1 fb-1
DØ: http://www-d0.fnal.gov/Run2Physics/WWW/results/np.htmCDF: http://www-cdf.fnal.gov/physics/exotic/exotic.html
Main Injector
TevatronDØCDF
Chicago
p source
Booster
Unless there are good reasons, I’ll pick examples in either one.
Still the energy
frontier
J.-F. Grivaz SUSY-06 June 16, 2006 4
New Gauge Bosons
J.-F. Grivaz SUSY-06 June 16, 2006 5
Extra Gauge Bosons
M(Z’-seq.) > 850 GeV(somewhat lower limits in)
(canonical E(6) models)
MT = M(electron-pT,missing-ET)
M(W’-seq.) > 788 GeV
e.g., W’ in L-R models Z’ within E(6) GUTs
Beauchemin
J.-F. Grivaz SUSY-06 June 16, 2006 6
Supersymmetry
J.-F. Grivaz SUSY-06 June 16, 2006 7
SUperSYmmetryAt such a conference, no “What is SUSY ?”, or “Why SUSY ?”
Which SUSY ?
More or less constrained MSSM, à la mSUGRAneutralino-LSPwith or without R-parity violation
Gauge Mediated SUSY Breaking gravitino-LSP and neutralino-NLSP
Anomaly Mediated SUSY Breakingwino-LSP and long-lived chargino
Split SUSYlong-lived gluino
J.-F. Grivaz SUSY-06 June 16, 2006 8
(m)SUGRA
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
m0 m1/2 tan() A0 sign()
J.-F. Grivaz SUSY-06 June 16, 2006 9
Trileptons• 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)
General strategy (similar in CDF and DØ):Two isolated (rather soft) e or Require some Missing ET () channel-dependent cuts (e.g. anti Z, )- An isolated third lepton or track (sensitive to ’s), or- Two same sign leptonsMain backgrounds: DY, WW, WZ, W (+ a bit of bb and mis-ID)
Strologas Hohlfeld
J.-F. Grivaz SUSY-06 June 16, 2006 10
CDF AnalysisLumi(pb-1)
Total predictedBackground
Observd data
ee,e, 710 6.801.00 9
+e/ (low-pT) 310 0.130.03 0
ee+track 610 0.480.07 1
ee + e/ 350 0.170.05 0
+e/ 750 0.640.18 1
e +e/ 750 0.780.15 0
DØ Analysis Lumi (fb-1)
Total predicted Background
Observd data
ee+track 1.2 0.820.66 0
+track 0.3 1.750.57 2
e+track 0.3 0.310.13 0
SS 0.9 1.1 0.4 1
e+track 0.3 0.580.14 0
+track 0.3 0.360.13 1
The results of the various channels are combined, “weighted” according to their sensitivity, with overlaps taken into account.
Cross-section upper limits & mass lower limits within specific models.
Missing ET
in +e/Missing ET pT(3)
in ee+track
…and in the end…
J.-F. Grivaz SUSY-06 June 16, 2006 11
m0 = 60 GeV 2-body decays enhanced ()s mixing on ( sL component) decays to ’s enhanced ()
Models = “favorably tweaked” mSUGRABoth CDF and DØ set ms = mse = ms
m(sl) = m(20) +
only 3-body decays ()s mixing off (no sL component) decays to ’s = to e/ ()
Some work ahead for the TEV-WG…
J.-F. Grivaz SUSY-06 June 16, 2006 12
Generic squarks and gluinos
Strong production ( Large cross sections ) of:• sq-sqbar and sq-sq at least 2 jets + missing ET (sq q) • gl-gl at least 4 jets + missing ET (gl qq)• sq-gl at least 3 jets Cascade decays complicate the picture model needed (mSUGRA)
DØ three analyses optimized for each of these processesreduces QCD to a negligible level
CDF 3-jet analysis optimized mostly for m(sq) m(gl)larger QCD background, estimated from control regions
Main backgrounds:• Instrumental (QCD multijets with fake missing ET)• (W(missed lepton)+) +jets (also from ttbar)• (Z ) +jets (irreducible)
Martinez Bargassa
J.-F. Grivaz SUSY-06 June 16, 2006 13
Main analysis cuts:• Data cleaning• Jet1,2(,3(,4)) pT
• Missing ET • HT = sum of jets pT’s• Lepton veto• Angles (jet,missing ET)
Analyses Background expected
Events observed
DØ 2 jets 4.8 4.5 6
DØ 3 jets 3.9 1.5 4
CDF 3 jets 8.2 2.9 2
DØ 4 jets 10.3 2.4 10
HT225 GeV
(m(gl)=240 GeV)
J.-F. Grivaz SUSY-06 June 16, 2006 14
Mgl > 387 GeV (when Mgl~Msq)Mgl > 241 GeV & Msq > 325 GeV
You have seen or will see other versions of this plot.
CDF vs DØ differences:• 371 vs 310 pb-1
• tan = 5 vs 3 (little impact)• 4 vs. 5 flavors (little impact)Theoretical uncertainty onthe signal cross section:• CDF includes it as a systematic uncertainty in the computation of the cross section limit• DØ reduces instead the theoretical cross section by its uncertainty (more conservative): yellow band…and CDF was a bit lucky.
Some work ahead for the TEV-WG…
J.-F. Grivaz SUSY-06 June 16, 2006 15
stR
StopA light stop can be expected:top-Yukawa impact in RGE First scenario considered by DØ:
(relevant as long as m(st) < m(b)+m(W)+m())(in SUGRA, needs M1 < M2 at GUT scale)
1 c-jet (soft tag)+ missing ET
(optimized for various m(st),m())
Main backgrounds: W/Z+jets
+ Large L-R mixing
stop NLSP and LSPwith stc (FCNC)
m(st) = 130 GeVm() = 50 GeV
Bargassa
J.-F. Grivaz SUSY-06 June 16, 2006 16
Light sneutrino st b l s 2 leptons (+b-jets) + missing ET (s)
(optimized for various m(st),m(s))
Stop exclusion up to m(top)
Second scenario considered by DØ:
e and final states analyzedMain backgrounds: Z at low mass, top at high mass
e analysis: ST=pT(e)+pT()+missing ET
with two signal examples
Stop Bargassa
J.-F. Grivaz SUSY-06 June 16, 2006 17
SbottomA light sbottom can be expected at large tan.DØ searched for sbottom pair production, with sbb
1 b-jet + missing ET (optimized for various m(sb),m())
CDF searched for sbottom fromdecays of pair-produced gluinos: gluino b sb (100%) 3/4 b-jets + missing ET
With 156 pb-1, sbottom masses up to 240 GeV are excluded IF m(gluino) < 280 GeV (and m() = 60 GeV)
m(sb) = 140 GeVm() = 80 GeV
BargassaMartinez
J.-F. Grivaz SUSY-06 June 16, 2006 18
R-parity violationPossible additional terms in the superpotential:
WRPV ijkLiL jE k ijk LiQ jD k ijkU iD jD k
With a term, only RPC pair production, mostly + and 20,
with (cascade) decays to LSP’s followed by RPV decays
e
e-
~
01
~
121
e.g. 4 charged leptons + missing-ET
With a ’i11 term, also resonant production: e.g.
J.-F. Grivaz SUSY-06 June 16, 2006 19
R-parity violation: ijk
DØ: 121, 122, 133 considered Three trilepton searches combined:eee/ 0.90.4 (background /e 0.40.1 (events 0 candidateee 1.31.8 (expected
NN -ID validated with Z
CDF also used clean four-lepton topologies:0 candidate vs 0.0080.004 bg. expected
For 133, ee most powerful at large tan and low m0:
m(10) > 115 GeV
for tan = 20, A0 = 0, 0 and m0 = 100 GeV
Autermann
J.-F. Grivaz SUSY-06 June 16, 2006 20
R-parity violation: ’ijk
DØ: ’211 resonant production
Reconstruct:m(smuon) = m(jj)m(1
0) = m(jj)
No accumulationm(smuon) > 210 to 363 GeV
for’211 > 0.04 to 0.10
(tan=5, A0=0 and < 0)
CDF: ’333 pair production
Look for (e/)(hadrons) +2 jets
2 candidates vs. 2.30.5 bg.
(Also LQ3)
Autermann Martinez
J.-F. Grivaz SUSY-06 June 16, 2006 21
Neutral Long Lived ParticlesDØ search motivated by 3 dimuon events in the NuTeV experiment
Production and decay model: SUSY RPV with a small 122
Look for displaced dimuon vertices (5 to 20 cm)
Calibrate with Ks decays
0 candidate vs. 0.81.6 bg.
Convert NuTeV (p-p at 38 GeV)
to DØ (p-pbar at 1.96 TeV)
(383 pb-1)
Autermann
J.-F. Grivaz SUSY-06 June 16, 2006 22
Charged Massive Stable ParticlesLong-lived charginos are expected in some AMSB models
with a “wino-LSP” (small – 10 mass difference)
They would appear in DØ as slowly-moving muons Make use of the time information of the muon system scintillators
For a 150 GeV chargino:0 candidates for 0.690.05 bg.
Gershtein
J.-F. Grivaz SUSY-06 June 16, 2006 23
Gauge Mediated SUSY BreakingIn GMSB, the LSP is a light gravitino G
A 10 NLSP decays into +G
All backgrounds determined from data(fake photons from dijet events, We+/jet)
pT() > 25 GeV Missing ET > 45 GeV
4 candidates vs. 1.80.7 bg.
“mGMSB Snowmass slope”(N=1, Mm = 2, 0, tan = 15)
Signal dominated by 20 production
m(10) > 120 GeV
Inclusive search by DØ for + missing ET
Gershtein
J.-F. Grivaz SUSY-06 June 16, 2006 24
Stopped GluinosIn “Split-SUSY”, squarks are ultra-heavy long-lived gluinosSuch gluinos form R-hadrons which may stop in the DØ calorimeter.
Backgrounds: beam and cosmic muons, measured
in data.
Strategy: look for a randomly oriented
monojet in an otherwise empty event
(diffractive trigger).
After a while, they decay into a gluon + 10
(q-qbar-10 is also possible).
(A. Arvanitaki et al., arXiv:hep-ph/0506242)
m(10 ) = 50, 90, 200 GeV
Excludes gluino massesup to 300 GeV
Gershtein
J.-F. Grivaz SUSY-06 June 16, 2006 25
Indirect limits from BsSM: Bsis heavily suppressed
910 ) 9. 0 5. 3( ) (
s B BR
SUSY: large enhancement
Huge dimuon backgroundDiscriminate using• Decay length• Isolation• PointingNormalize to B+J/ K+
Limit at 95% C.L (780 pb-1): BR(Bs) < 1. 10-7
1 candidate event selectedin a 60 MeV mass window
vs. 1.40.4 bg. expected
CDF search:
Carena
GeV
J.-F. Grivaz SUSY-06 June 16, 2006 26
Extra Dimensions
J.-F. Grivaz SUSY-06 June 16, 2006 27
Extra-dimensions…come in many flavors: LED, TeV-1, UED, RS
Two classes of models considered:• ADD
2 to 7 large (sub mm) EDsgravity propagates
freely in the bulkKK excitations
cannot be resolved• RS
one 5th (infinite) ED with warped geometry
gravity is localized on a brane other than the SM
KK excitations have spacings of order TeV
J.-F. Grivaz SUSY-06 June 16, 2006 28
Large Extra DimensionsTwo 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
gq
q GKK
gg
g
V
V
GKKGKK
f
ff
fVirtual graviton exchangeModifies SM cross sectionsSensitivity to the theory cutoff MS
(MS expected to be MD)
J.-F. Grivaz SUSY-06 June 16, 2006 29
MonojetsCDF search in 1.1 fb-1:
Main selection cuts:• one high pT jet ( 150 GeV) (soft jets from ISR are allowed)• isolated lepton veto• Missing ET away from jets• Missing ET 120 GeV
Main background: (Z ) +jetCalibrated with (Zll and Wl) + jet
QCD is negligible
779 events selected819 71 expected
Beauchemin
J.-F. Grivaz SUSY-06 June 16, 2006 30
High pT dileptons & diphotonsDØ search in 200 pb-1 combines ee and to maximize the sensitivity
Still world tightest limits:MS > 1.36 TeV
MS >1.43 TeV w/DØ@Run Iin the GRW formalism
Fit of Data to SM+QCD+LED(MS)
J.-F. Grivaz SUSY-06 June 16, 2006 31
Randall – Sundrum gravitonsHere too, most of the sensitivity is in diphotons (BR = 2ee)
DØ combined ee + as for the LED search doesn’t add much
Two model parameters:Mass and coupling (/MPl)
For /MPl = 0.1: M 785 GeV
J.-F. Grivaz SUSY-06 June 16, 2006 32
Looking for the unexpected
J.-F. Grivaz SUSY-06 June 16, 2006 33
Signature based searches
+ X in 0.7 to 1 fb-1
X=e 2 vs. 4.50.8X= 0 vs. 0.50.1X= 4 vs. 1.90.6
l + Missing ET in 0.3 fb-1
l=e 25 vs. 19.83.2l= 18 vs. 15.32.2
(CDF Run I excess not confirmed)
(Also multileptons + photon)
CDF:
Goncharov
J.-F. Grivaz SUSY-06 June 16, 2006 34
Final remarks
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.
CDF and DØ have now begun to explore clearly virgin territories.
Already 1.3 fb-1 on tape, only partially deciphered Expect many new results in the coming months
J.-F. Grivaz SUSY-06 June 16, 2006 35
Back-up Slides
J.-F. Grivaz SUSY-06 June 16, 2006 36
J.-F. Grivaz SUSY-06 June 16, 2006 37
J.-F. Grivaz SUSY-06 June 16, 2006 38
~~ 0
1ct
~~ /
1
bt
'~~ 0
1ffbt
(tree level)
(loop)
Stop decays in mSUGRA
m0 = 200 to 600 GeV (50 GeV step)
m½ = 110 to 180 GeV (10 GeV step)A0 = –500 to –1000 GeV (100 GeV step)
tan = 3 and 10 to 50 (10 step)Both signs of