Current results and future prospects at Tevatron

1
Current results and future prospects at Tevatron
T. Maruyama (Univ. of Tsukuba) For CDF / D0
collaborations

• Contents
• Recent status and plan of Tevatron
• Physics program at Tevatron by 2009 shutdown
• Recent physics results and prospects
• (1) Top and indirect Higgs search
• (2) direct Higgs search
• (3) flavor sector
• Summary

2
CDF / D0 collaborations
CDF Collaboration (12 countries, 600 authors)
Compact collaborations ! (compared to LHC)
3
2.8
2.4
4
Tevatron complex in Run II
Recycler ring to reuse the pbar which did not
interact to proton. Electron cooling electron
is to run parallel to beam to make
beam emittance smaller. Tev 36 X 36 bunch
colliding

• p p collisions at ?s 1.96 TeV.
• Peak luminosity ?1.7?1032 cm-2 s-1.
• p recycler is being used as p stacking recently.
  (not for recycler) success!!
• Electron cooling was successfully installed for
  shots to Tevatron. (Obtaining smaller beam
  emittance, We will see difference more in
  future.)
• Designed (in 2004) luminosity was delivered
  successfully in FY05.

5
Data delivered to date
1.44 fb-1 delivered, 1.15 fb-1 on tape (CDF) (80
data taking eff. - 20 ineff. Includes 5
Trigger/DAQ dead time) 1.0 fb-1 good for physics
without silicon, 0.9 fb-1 good for physics with
silicon D0 has similar amount of the data in the
tape!
6
Projected Data Sample Growth
7
Performance of Tevatron
Real peak luminosity up to Sep-2005
FY02 FY03 FY04 FY05
100E30
100E30
Sep-2005
Sep-2005
Sep-2009
Designed peak luminosity to obtain 8.5 fb-1
400 pb-1
Tevatron is working well !!
Integrated luminosity in FY05 Red designed,
blue base (min.)
8
DAQ / Trigger Specifications (CDF case)
Run IIa L1 Accept not achieved due to higher
than specified Silicon Readout and L2 Trigger
execution times. Assume 5 from readout and
5 from L2 processing
Triggers (Run IIb) for W, Z, Top, WH, ZH, H-gtWW,
SUSY (partial), LED, Z
50 of bandwidth at 3x1032 cm-2s-1 Studying
further improvement
9
High Lum. Impact on Reconstruction / Physics

• Analysis Techniques
• W Mass (example)
• At higher inst. luminosity, there should be
  more of inelastic interactions at each bunch,
  so we expect missing ET can be skewed.
• ? Using lepton PT would give smaller systematic
  uncertainty than that using traditional
  transverse mass.

0.2 x 1032 cm-2s-1 1.0 x 1032 cm-2s-1 2.0 x 1032
cm-2s-1 3.0 x 1032 cm-2s-1
MTW
pTlepton
10
Physics program of Tevatron before shutdown

• Tevatron Shutdown 2009 (2008?)
• What are the interesting Tevatron physics
  topics under running of the LHC?
• How do we reduce the time rug between provided
  luminosity and that used in analysis?(Integrated
  luminosity is 1.1fb-1 now, while CDF uses
  0.7fb-1 in winter )
• What are the main physics programs? (related to
  trigger)
• example
• flavor sector BS mixing DmS / Dmd
• rare decay BS ? mm etc
• electroweak sector top W mass
• top
  mass
• Higgs
  Boson search
• New Physics search non-SM Higgs
• 
  SUSY, extra dim.,
• 
  compositeness etc.

11
top and indirect Higgs search
12
Indirect Higgs mass search with Mtop and MW

• Higgs mass can be constrained from precise W mass
  and top quark mass measurements using the formula
  above (radiative correction). Also sensitive to
  new physics if loop exists.
• Current CDF Run II best single measurement ?
  173.53.9-3.8GeV/c2 and all combined value (Run
  IRun II, CDFD0, pick up best meas. in each
  channels) ? 172.7 2.9 GeV/c2
• Current best MW is inferred by LEP2 (80.392
  0.039 GeV/c2), and world average is 80.410
  0.032 GeV/c2.
• Best Higgs mass ? 9145-32 GeV/c2 and upper
  limit 186 GeV/c2 _at_ 95 C.L.

Old result in 2004
13
Combination of top mass measurements
Use only best analyses from each decay mode, each
experiment.
Both Ws -gt ln (dilepton 5) One W-gt2jets / one
W-gtln (leptonjets 30) Both Ws -gt
2 jets (all had 44)
All systematic uncerainty correlations are taken
into account as properly as possible!!
(statistically independent)
Run I (100pb-1) Run II(350pb-1)
14
Future Improvement
Combined Result

• Basic improvement by ?1/?L
• - L?0.7fb-1 in this winter.
• - Further improvement on JES by direct b-jet
  JES calibration by Z ? bb events. Current b-jet
  JES taken same as generic jet additional
  uncertainty according to LEP/SLD measurements.
• Sig./Bkgd. Modeling (ISR/FSR/Q2 dependence etc.)
  can be improved by using our own data.
• Measurement in All Hadronic mode is coming soon.

15
New Method to constrain Jet Energy Scale

• Use W?2 jets to calibrate Jet Energy Scale (fully
  in situ). This scale is applied to b-jets and
  light-quark jets.
• Do a cross-check for our standard JES calibration
  obtained in dijet, photonjet environment.
• Two dimensional fit for JES and Mtop
  simultaneously.

Mjj(W)
This method makes the largest systematic
uncertainty as statistical issue !! We will
achieve uncertainty Mtop 2 GeV/c2 w/o no
improvement at 2 fb-1. (note this is only
single measurement at CDF)
16
Results on the JES from the 2D Fit
2 b-tag jets sample
1 b-tag jets 4 high ET jets
Variation of Mjj as a func. of JES (s 3
GeV/c2)
Data Mjj
1 b-tag jets 3 high 1 loose
0 b-tag jets
JES (s)
Mtop 173.52.7-2.6(stat) 2.8 (syst) GeV/c2
173.53.9-3.8 GeV/c2
Result of 2D fit
Mtop (GeV/c2)
PRL / PRD accepted ( to be published )
17
Summary of Top Mass Measurements
Many cross-checks, combined best ones from
each channels

18
W mass status (CDF)
Chamber wire positions aligned lt10 ?m Passive
material between IP and COT x-ray using ? ?
ee-, check es E/p tail Momentum scale J/?
mass, check Upsilon and Z mass Energy scale
es E/p peak, check Z mass Uncertainty on MW
total 76MeV/c2 ????? 85, e 105 MeV/c2
center value is still blinded.
E / p of W electrons
1 / pT??(GeV-1)
19
Electroweak Projections
3
2
50
20
Other Top Quark Properties

• Understanding on top quark profile will be
  significantly improved by statistics in next a
  few years.
• Any significant deviation from standard model
  prediction could indicate new physics.
• e.g. cross
• section is
• sensitive
• to
• production
• and decay
• anomaly.

21
Does something new produce ttbar?

• Search for new massive resonance decaying to top
  pairs
• Constraint top mass 175GeV/c2
• D0 uses lepton4jets (b-tag) with traditional
  kinematic fitter, while CDF uses lepton4jets
  (no-btag) with matrix element technique.
• Fix most of SM backgrounds to expected rate
• Use theory prediction of 6.7pb for SM top pair
  production

Interesting fluctuation in both
experiments double stat. in winter
22
Direct Higgs search
23
Standard Model Higgs
Integrated luminosity (/fb)

• Precision data prefer light SM Higgs
• SUSY requires light Higgs.
• studies in 1999 and 2003 predicted consistent
  result
• 2 fb-1 95CL exclusion at mH115 GeV/c2
• 5 fb-1 3s evidence at mH115 GeV/c2
• If Higgs mass is small, TeV could compete.

24
Direct Higgs Search
Both CDF and D0 have started the hunt
25
(No Transcript)
26
How Do We Get There?

• Assume current analyses as starting point
• Factor 2003 Higgs sensitivity study / current
  analyses
• Reevaluated all improvements using latest
  knowledge

Expect factor 10 improvements and CDFDØ
combination
27
Improvement example Lepton Selection

• Forward leptons factor 1.3
• Current analyses use only up to ?lt1.1
• Electrons
• CDF
• Forward electrons used already by other analyses,
  e.g. W charge asymmetry
• Up to ?lt2.8
• Central electrons recently improved efficiency
  from 80 to 90
• Factor 1.34 in acceptance
• Muons
• CDF
• uses only up to hlt1.0
• can be extended since we have detector.

W electron charge asymmetry
PRD 71, 051104 (2005)
75 efficiency
35 lt ETelectron lt 45 GeV
28
EJet Scale Resolution Status / Improvements

• Jet energy scale uncertainty
• precision measurements (Mtop), searches
• now 2.5 uncertainty for jets in top decays
• further improvements
• generators, higher order QCD
• better scale for ET gt 100 GeV region
• complete by end of this year
• Jet energy resolution
• currently 17, goal 10-11
• further improvements
• combine track, calorimeter Info 2
• expand cone size 2
• b-jet specific corrections1-2
• sophisticated algorithms 1-2
• complete by spring 2006

H --gt bb mass (GeV)
29
Non-SM Higgs A?bb and A?tt

• Supersymmetry (MSSM)
• 2 Higgs doublets gt 5 Higgs bosons h, H, A, H
• High tanb
• A degenerate in mass with h or H
• Cross sections enhanced with tan2b due to
  enhanced coupling to down-type quarks
• Decay into either tt or bb
• BR(A ?tt) 10, BR(A? bb) 90
• Exact values depend on SUSY parameter space
• Experimentally
• pp ? AbX ? bbbX
• pp ? AX ? tt X

• C. Balazs, J.L.Diaz-Cruz, H.J.He, T.Tait and C.P.
  Yuan, PRD 59, 055016 (1999)
• M.Carena, S.Mrenna and C.Wagner, PRD 60, 075010
  (1999)
• M.Carena, S.Mrenna and C.Wagner, PRD 62, 055008
  (2000)

30
MSSM Higgs Searches
Accepted by PRL, hep-ex/0508051
? 200 GeV M2 200 GeV Mgluino 0.8
MSUSY MSUSY 1 TeV, Xt v6 MSUSY (mhmax) MSUSY
2 TeV, Xt 0 (no-mixing)
CDF Preliminary 310 pb-1
31
Flavor sector
32
BS BS mixing Motivation
0
0
Measure side of unitarity triangle Dms / Dmd
B mixing box diagram within SM
taking ratio to reduce theoretical
uncertainties

• Yellow Band Dmd measurement 15 uncertainty
• Orange Band Lower limit on Dms Upper Limit on
  Vtd
• The lower limit on Dms already gives a
  constraint to the Triangle
• CKM Fit result Dms 18.36.5-1.5 (1s)
• 2005 EPS

from Dmd
from Dmd/Dms
Lower limit on Dms
33
Bs Mixing Analysis Winter 2005
900 signal events with Bs ? Ds?, Dsl?? where Ds
? KK, ????????
With 355 pb-1 CDF 95CL Limit 7.9 ps-1 CDF
Sensitivity 8.4 ps-1
526 33 events
34
Bs Mixing Analysis Fall 2005

• Hadronic modes
• Improved tagger (larger B0 calibration sample, NN
  for jet charge)
• Improved primary vertex (event-by-event reco.,
  most inner Si layer added, better track
  resolution understandings )
• Added a new decay mode Bs ? DS 3p (20 increase)
• Semileptonic modes
• SVT 2-track trigger - greater than x2

With 355 pb-1 CDF 95CL Limit 8.6 ps-1 CDF
Sensitivity 13.0 ps-1
CDF Preliminary
CDF Preliminary
35
?ms Sensitivity Projections
36
Rare Decay Bs?mm-
SM prediction (highly suppressed)
Expected signal 0, any signal would indicate
new physics
(Buchalla Buras, Misiak Urban)
e.g. SUSY may enhance the rate
(Babu, Kolda hep-ph/9909476 many more)
CDF results 0 event was observed, corrsponding
to Br lt 1.6 x 10-7
37
Rare Decay Bs?mm- (2)

• Projected reach (assuming no
• improvements to current analyses)
• Exclusion at 90 C.L.
• 4 fb-1 BR lt 4 x 10-8
• 8 fb-1 BR lt 2 x 10-8
• Discovery at 5s
• 4 fb-1 BR 1 x10-7
• 8 fb-1 BR 7 x10-8
• ATLAS (SN-ATLAS-2003-003)
• 5s discovery with L1 fb-1 if Br5x10-8
• 5s discovery with L300 fb-1 for SM value

ATLAS
38
Lifetimes

• ?b0 ? J/???0

• Bc0 ? J/??e?

CDF Preliminary 360 pb-1
CDF Preliminary 370 pb-1
? 1.45 0.13 0.02 ps Single best measurement
in a fully reconstructed decay mode
? 0.474 0.073-0.066 0.033 ps Worlds best
TeV is making competitive and world leading
measurements for all the heavier B hadrons.
39
Observation of Bc ??J????
With 0.8 fb-1, CDF M(Bc) 6275.2 4.3 (stat.)
2.5 (syst.) MeV Lattice QCD Cal. M(Bc) 6304
12 18-0 MeV hep-lat/0411027
Used data up to Sept.4, 2005 and approved as of
Nov.10, 2005. Demonstrates physics results with
data through Feb.05 by next summer.
40
So much more !! (but no enough time to show)
ttbar cross secton
Missing ET vs DF (WW)
Jet PT spectrum
Charged Higgs excluded region
LQ search
Qh for single top
cosq for W helicity
Anomalous coupling of Wg
Z search
BC meas. (J/Y p)
W search
g ET of Wg
41
Summary

• Tevatron is delivering good luminosity with
  almost same level as designed one.
• For higher luminosity in near future, CDF/D0
  should consider trigger and physics impact.
• CDF and D0 are thinking on what are meaningful
  physics programs during running of LHC programs.
• Core physics programs such as top mass has good
  shape and perspectives. (Tevatron average already
  gives the uncertainty by 2.9 GeV/c2 at 350
  pb-1)
• To achieve the sensitivity study in 2003, some
  significant improvements is needed for Higgs
  search. CDF / D0 are making effort to achieve it.
• TeV is producing impressive and important
  results !!

42
Backup slides
43
CDF at Tevatron
Multi-purpose detector precision meas. search
for new physics
polar angle ?

• Silicon detector (SVX)
• top event b-tag 60
• COT drift chamber
• Coverage hlt1
• sPt / Pt 0.15 PT
• Calorimeters
• Central, wall, plug
• Coverage hlt3.6
• EM sE / E 14 /ÖE
• HAD sE / E 80 /ÖE
• Muon scintillatorchamber
• muon ID up-to h1.5

COTtracking
44
Tagging and Jet Energy Calibration

• B Tagging (secondary vertex)
• Hadronic Tau Tagging
• Evisible gt 30 GeV
• 50 efficient
• lt0.5 mis-identified

Better algorithms Neural Network
Forward
Jet mis-id () efficiency ()
Loose (1.8 mistag) Tight (0.6 mistag)
?E/E 3 at 50 GeV xx at 100 GeV xx at 200
GeV Submitted to NIM
45
Top Mass vs ttbar cross section
46
Z?bb

• Trigger
• 2 SVT track 2 10GeV clusters.
• Offline Cuts
• N2 jets w/ ETgt20GeV, hlt1.5 (JetClu cone 0.7).
• Both jets are required to have secondary vertex
  tag.
• Df(j1,j2)gt3.0.
• ET3rd-jetlt10GeV.

47
MSSM Higgs Present and Future

• Current data (310 pb-1) has no excess
• Sensitivity different in other regions of
  parameter space
• Close gap to LEP with increasing datasets
• tanb40mtop/mb reached for mAlt240 GeV/c2

48
New Phenomena Searches
X ??ee- searches (paper in preparation) X
??top pair resonance searches (paper in
preparation)
Z in ee
CDF Preliminary 448 pb-1
Mee (GeV/c2)
CDF Preliminary 319 pb-1
Projections
49
Combination of top mass measurements
Both Ws -gt ln (dilepton 5) One W-gt2jets / one
W-gtln (leptonjets 30) Both Ws -gt
2 jets (all had 44)
Use only best analyses from each decay mode, each
experiment.

• Correlation
• uncorrelated
• stat.
• fit method
• in situ JetEnergyScale(JES)
• 100 w/i exp (same period)
• JES due to calorimeter
• 100 w/i channel
• bkgd. model
• 100 w/i all
• JES due to fragmentation,
• signal model
• MC generator

Run I (100pb-1) Run II(350pb-1)
50
What if this were the only Mtop msmt?
51
Reconfirmation of BC

• BC meson was discovered in 1998 with CDF Run1
  data.
• -- mass 6.4 0.4 GeV/c2
• -- lifetime 0.46 0.18 ps
• CDF Run2 reconfirmed the existence with higher
  statistics
• Right plot
• BC signal with J/YeX
• Invariant mass for mme
• ( 360 pb-1 Run2 data.)
• 178 candidates against
• 63.4 4.9 13.6 bkg ev.
• in 4ltMlt6 region (5.9 s)

52
BS lifetime
World second best value !!
53
Data for Physics (up to Aug. 23, 2005)
Recorded
QCD Beyond SM Electroweak B Top
SM Higgs
Sep-Dec 05 Shutdown
COT Compromised Period
54
Data Taking Efficiencies
Initial Luminosity (1030 cm-1s-1)
Data Taking Efficiency
Detector downtime Beam losses / incidents Trigger
deadtime 5 our choice
80
55
TeV Projected Peak Luminosity to get 8fb-1
56
Luminosity Profile
57
Rare Decay Bs?mm-
SM prediction (highly suppressed)
(Buchalla Buras, Misiak Urban)
Expected signal 0, any signal would indicate
new physics
e.g. SUSY may enhance the rate
Invariant mass of mm different m detector (top
and bottom figs.)
(Babu, Kolda hep-ph/9909476 many more)
CDF results 0 event was observed. corrsponds
to Br lt 1.6 x 10-7 (BKG 0.81 0.21 top
0.66 0.13 )
58
B Mixing in Standard Model

• Within the SM
• B mixing Box diagram
• q d (B0) or s (Bs)
• Dmd 0.5100.005 ps-1 (HFAG 2005)
• f2BdBBd (2283010 MeV)2
• Lattice QCD calculation
• Vtd determination limited by 15
• Ratio between Dms and Dmd

• Many theoretical uncertainties are cancelled in
  the ratio
• x 1.210.040.05
• Determine Vts/Vtd 5 precision

59
Unitarity Triangle

• CKM Matrix (Wolfenstein parameterization)
• Unitarity of CKM Matrix
• Unitarity Triangle

• VcbVts
• Vcd is known with 5 precision
• 0.2240.012
• Primary objection of Bs mixing
• Precise determination of one side of the
  Unitarity Triangle

60
Analysis Strategy

• Mixing
• (1) Reconstruct Signal
• Flavor eigenstate
• (2) Determine B decay time
• Decay time reconstruction
• Lifetime measurement
• (3) Identify the initial flavor of B meson
• Flavor tagging
• B0 mixing
• (4) Bs Mixing
• Blind Analysis

61
Silicon Vertex Trigger (SVT)

• Level 2 Silicon Vertex Trigger
• Use silicon detector information
• Good IP resolution
• Trigger on displaced track
• beamline reconstruction
• update every 30 seconds
• IP resolution 50 mm
• 35mm beam size 35mm SVT

62
Hadronic and Semileptonic

• Reconstruct two different signatures
• Hadronic Exclusive
• Semileptonic Inclusive
• These are different
• Trigger, signal yield
• Background
• Missing momentum
• Sensitivity for Bs mixing
• Hadronic
• Less signal yields
• Good sensitive at higher Dms
• Semileptonic
• Higher signal yield
• good sensitivity at lower Dms
• These two signatures are treated differently,
  and the results are combined together.

Hadronic
Semileptonic
63
Signal Yield Summary
64
Flavor Tagging

• Current result
• Opposite side tag only
• Opposite side tagging
• Use the other B in the event
• Semileptonic decay (b g l-)
• (1) Muon, (2) Electron
• Use jet charge (Qb -1/3)
• (3) Jet has 2ndary vertex
• (4) Jet contains displaced track
• (5) Highest momentum Jet
• Same side tagging
• Use fragmentation track
• B0, B, and Bs are different
• Kaon around Bs PID is important

65
Dmd Summary
1st error statistical 2nd error systematic

• World average Dmd0.5100.005 ps-1
• Total eD2 1.11.4
• All dilution scale factors consistent with 1
• Hadronic 1525 uncertainty
• Semileptonic 515 uncertainty

66
Amplitude Scan for B0

• Introduce Amplitude in Likelihood
• Amplitude will be consistent with
• 1 if there is mixing
• 0 if there is no mixing
• Amplitude scan
• Fit the amplitude for fixed Dm
• Amplitude A, uncertainty sA
• Repeat the fit with different Dm
• Example for B0 Hadronic sample
• Amplitude 1 at Dm 0.5 ps-1
• Amplitude 0 at Dm gtgt 0.5 ps-1

Hadronic B0 sample
Hadronic B0 sample
67
Algorithms for Bs mixing Status / Improvements

• Complex meas.s involving many detector systems
  and analysis tools
• Triggering optimized SVT algorithms
• Reconstruction modes
• Currently adding Bs ? Ds 3? (x1.5)
• Will add Bs ? Ds? by summer 2006
• Currently adding Bs ? Dsl? sample
• using SVT 2-track triggers (x2)
• Tagging (?D2)
• e, ?, jet charge (1.5)
• Same-side K tagging in progress (2)
• Decay length resolution
• Improving vertex resolution by 1020 for larger
  ?ms
• Implementing into analysis by fall 2005
• Reducing systematic uncertainties by fall 2005
• Hadronic modes - better calibration in flavor
  tagging
• Semileptonic modes - better understanding of
  backgrounds

68
Production of the Top quark at the Tevatron
Top quarks are primarily produced in pairs
(s7pb), via qq (85) and gg(15), - LHC via
gg (90) ttop 4 x 10 -25 s (due to large
mass) Top decays as free quark (L-1 (200MeV)
-1 10 -23 s)

• Dilepton (5, small background)
• 2 high-PT leptons(e/m), 2 b jets,
  large missing ET
• LeptonJet (30, manageable bgrnd)
• 1 high-PT lepton(e/m), 4 jets (2 b jets),
  large missing ET(30)
• All-hadronic (44, large background)
• 6 jets (44)

69
Top Mass Analysis using the template method

• c2 mass fitter
• Finds top mass that fits event best
• One number per event
• Additional selection cut on resulting c2

Data
Wbb MC
Massfitter
tt MC
Signals/background templates
Datasets
Data
Likelihoodfit
Result
Likelihood fit Best
signal bkgd templates to fit datawith
constraint on background normalization
70
Event Selection

• Final State (LeptonJet channel) lepton,
  neutrino plus 4jets
• Datasets (Mar, 2002 Aug. 2004)
• 318pb-1 for High-pt central electron/muon
  triggers
• High pt electron or muon with Pt gt 20 GeV
• Isolated
• Electron EM cluster in calorimeter with
  matched track
• Muon track matched to hits in muon
  chambers,
• MIP ionizing energy in
  calorimeter
• Large missing Et gt20 GeV
• Leading 4 jets
• Reconstructed with cone algorithm (0.4) using
  calorimeter towers
• hlt2.0

71
B-tagging and Sample Division

• Signal/Background improvement
• (only 1-2 of Wjets contains heavy flavor)
• Big help to remove wrong choice in jet-parton
  assignment for Mtop
• Samples are divided to get the best sensitivity
  on top mass

Top Event Tag Efficiency 55 False Tag Rate (per
jet) 0.5
72
Jet Energy Correction
Determine true parton E from measured jet E in
a cone 0.4
Non-uniform response
Correction to central region using dijet balance
to make response uniform in ?
Correction to particle jets using dijet MC tuned
for single particle E/P, material, and
fragmentations due to non-linear and
non-compensating cal.
Diff. resp. of p0/pi- Non-linearity
Out-of-Cone correction to parton top-specific
correction to light quark jets and b-jets
separately
Shower, frag.
73
Mass Fitter (event by event)

• Try all jet-parton assignments with kinematic
  constraints, but assign b-tagged jets
  to b-partons
• Select the rec. mass Mt from the choice of lowest
  c2
• Badly reconstructed Mt (c2 gt 9 ) is removed

Top mass isfree parameter
All jets are allowed to be float according to
their resolutions to satisfy that
M(W)M(W-)80.4 GeV, M(t)M(t)
74
Reconstructed Top Mass Dist. at Mtop 178 GeV
More correct combination with b-tag
Mt(GeV/c2)
Mt(GeV/c2)
Mt(GeV/c2)
Mt(GeV/c2)
Bkgd is large in the 0-tag
75
Backgrounds
gt1-btag

• Wheavy flavor jets(bb,cc,c)
• Heavy flavor fraction from MC
• Normalized to data
• Wjets(mistag)
• Use measured mistag rate, applied to the data
• Multijetfake-W (jet-gte, track-gtm)
• Estimated from data
• Single top, dibson (WW,WZ)
• Estimated from MC

control
signal
76
Background templates
Mt(GeV/)
Mt(GeV)

• 0tag Wjets
• Tagged WHF, Mistag, fake-W, Single-top
• Shape mostly by ALPGEN MC, cross-check with data

77
-Log Likelihoods
Sensitivity mainly comes from 2tag and 1tagT
samples
78
Mjj templates (true Mtop, JES)
PDFs( Mjj JES, Mtop 180 ) 1tagL
PDFs ( Mjj Mtop, JES0)2tag
Mtop
Mjj
Mjj

• Mjj strongly depends on JES,
• but independent of Mtop

Mjj
79
Mt templates (true Mtop, JES)
PDFs ( Mt JES, Mtop180)1tagT
PDFs ( Mt Mtop, Mtop180)1tagT
Mtop
Rec Mt
Rec Mt

• Mt strongly depends on JES and Mtop

80
(No Transcript)
81
Jet Energy Systematics
A lot of work has been done to reduce the syst.
from jet-energy scale (a factor of two
improvement compared to last year). The new Run
II systematic uncertainties are at the same level
or better than Run I.
82
Test of the Jet Energy Corrections
0.1
0.1
-0.1
-0.1
PT
80
40
40
80
PT
Photonjets, di-jet, Zjets are used to
cross-check the jet energy corrections. Observed
differences between data, Pythia, and Herwig are
contained by the jet systematic uncertainties in
different ? regions.
83
Searches for SM Higgs

• CDF search for SM Higgs in several channels

• NEW updated results from
• Selection
• High pt lepton data (L319 pb-1)
• One high pt central e or m, large MET (METgt20
  GeV)
• 2 jets (at least one is tagged as b-jet)
• Veto events w/ gt1 lepton (suppress ttbar)

1st results soon
84
3x1
1x1
85
Run I Results using tracking calorimeter
method

• Using tracking information instead of
  calorimeter information could improve energy
  resolution.
• A plot below shows the study in Run 1 to improve
  the energy resolution
• Currently CDF is trying a few algorithms to
  improve.

86
Neural Net Selection

• Neural Net
• NN analysis done for ZH?llbb
• 16 input variables
• Improves S/vB by factor 1.44
• NN cut gt0.6
• Signal ?77.5
• Background ?15.4
• Mass cut 100?20 GeV
• Signal ? 53.7
• Background ? 15.8
• Equivalent lumi(S/vB)22
• 1.75 from 2003 HSWG study is achievable
• Using full shape (instead of cutting) may gain
  even more

87
WH Signal in ZH???bb Analysis

• This is easy!
• Got factor 2.4 now (CDF)
• S/vB increases 0.062 gt 0.096
• Luminosity factor(S/vB)22.4
• DØ observe factor 1.6
• Remarks
• ZH???bb analysis
• vetoes against isolated tracks, electrons and
  muons
• Exact factor depends on veto cuts
• Cross-talk with lepton and track-only selections
• can be further optimised with global view on all
  analyses
• Factor 2.7 of CDF study reasonable

88
CDF and D0 Detectors
multi-purpose detectors with

• Tracking in magnetic field.
• Precision tracking with silicon.
• Calorimeters.
• Muon chambers.

CDF
D0
Jet sET/ET 84/?ET (GeV/c2)