Tevatron Physics Results Implications for the LHC

1
Tevatron Physics Results Implications for the
LHC
Paul Grannis, for the CDF and DØ
collaborations ATLAS Physics Workshop, Aug. 3 2009
What about dem Mets?
2
Operations

• Fermilab expects to run the Tevatron through
  FY2011. The Tevatron is now delivering close to
  its upper projection L.

90
DØ efficiency to tape (93 in April). 80 of
total delivered gets into analyses.
now
Summer 09 results up to 5.8 fb-1, typically
4fb-1
Expect 12 fb-1 delivered 10 fb-1 to physics

• Detector subsystems should (almost) survive for
  12 fb-1 of data. (DØ silicon shown here Layer 0
  is OK inner detectors on layer 1 barrel not
  fully depleted after 9 fb-1.)

2
3
Physics output
Publications by year CDF DØ
Now 100 papers/year. Recent results based on
35 fb-1 so final data set will be 23X current.
Many analyses still improving faster than 1/L1/2
due to improvements in techniques No further
upgrades to detectors triggers are now stable.

• Physics analyses in CDF and DØ based in six
  working groups
• Top quark properties
• Electroweak bosons
• Heavy flavor (b,c) states
• Searches for phenomena beyond the SM
• QCD studies
• Higgs boson searches

This talk will select only some highlights of
interest to initial LHC program (and those that
will be Tevatron legacy). Many results will be
updated for Lepton Photon.
CDF and DØ are now taking students (10/expt) who
did ATLAS/CMS hardware and commissioning to do
Tevatron physics analyses for theses. A good
match!
3
4
Top quark
Top quark mass Tevatron average Mt173.11.2
GeV (0.7)
Have now exceeded the Tevatron goal expect the
final average mass to be below 1 GeV. Are now
reaching the systematic limit (heavy flavor jet
energy scale, signal model, jet
resolution). Reaching this precision will take
LHC experiments a while.
Best single top-antitop cross section measurement
(CDF) is 8 and uses the Z cross section to
reduce normalization uncertainty. Consistent
with theory for the measured Mt. Final
systematic limit should reach 6, less than the
10 theory error.
4
5
Top properties
W helicity in t decay p23 to see larger SM
discrepancy than observed. With 8 fb-1 and same
central value, p0.0024.
AFB0.1930.069 (3.2 fb-1) (NLO QCD 0.050.015)
Top-antitop mass difference 3.83.7 GeV Top
charge 4e/3 excluded at 92 CL
t t resonance excluded to 820 GeV. (Are already
into LHC regime where jets from boosted tops
merge, so kinematic fitting is not optimum.)
All statistics limited hints of non-SM behavior
exist so stay tuned. ( Tevatron legacy)
Hint of t quark?
5
6
EW single top production
t-channel Wb?t
s-channel W?tb
Final state is tb bbW

• Signal is small background is large. Analyses
  pull all the stops (BDT, BNN, ME, L fns). Both
  CDF/DØ now at 5s (3.2/2.3 fb-1). Analyses are
  statistics limited.
• New result 4.8s significance for t channel
  process alone. Separate s- and t-channel XS
  sensitive to BSM physics

0.94 -0.81
st 3.14 pb

• With full data set
• Expect dVtb/Vtb 0.08
• Sensitive to W gt 800 GeV
• H search with MH gt Mt
• Anomalous top couplings

Combining W helicity and single top
6
7
W boson mass
Recent DØ measurement (1 fb-1) gives
MW80.4010.043 GeV (CDF 80.4130.048 GeV in e
m, 0.2 fb-1). Requires control of systematics to
10-4
level (energy scale, recoil system calibration,
QED/QCD modeling). Precision is statistics
limited (mainly Z statistics) so will improve.
ultimate
Expect 2009 Tevatron (World) average MW with
errors 31 (23) MeV. (Tevatron dM lt LEP dM) With
10 fb-1, expect error 16 MeV/expt (12 MeV
combined), so world average dMW10 MeV. This
will be a challenge for LHC experiments to match!
But the overconstraint on SM with LHC Higgs
will be very strong.
ultimate
7
8
W/Z measurements

• ds/dpTZ measures QCD resummation parameter g2
  and is needed to reweight MC backgrounds for rare
  processes.

• New direct measurement of W asymmetry more
  precise than current PDF errors, so will
  constrain future PDF fits.

• AFB for qq ? Zg ? ll measures sin2qW for light
  quarks (recall the LEP/SLC discrepancy between
  sin2qW for leptons and heavy quarks). With 10
  fb-1, will have comparable precision for light
  quarks as LEP/SLD for b-quarks. AFB at high mass
  probes new physics.

• Direct measurement of W boson width from high
  transverse mass tail now WA uncertainty with 1
  fb-1 of 45 MeV. Project WA after 10 fb-1 20
  MeV (better than the current indirect
  measurement from W/Z sxBR ratio of 42 MeV)

8
9
Diboson cross sections
At Tevatron, Wg, Zg, WW, WZ, ZZ processes have
the smallest SM cross sections apart from Higgs.
With the DØ 5.7s observation of ZZ last summer,
all have now been observed.

• The diboson processes are important for several
  reasons
• Search for anomalous trilinear couplings (here
  LHC will do much better)
• They are backgrounds for even rarer processes
  (EW production of top, Higgs, ). Give
  experimental guidance on NLO/LO k-factors.
• Demonstration of techniques for Higgs search
  using a known rare process.
• Diboson measurements are dominated by statistics,
  so increase in data samples will help
  considerably.

dijet mass in 2 jetmissing ET (1st observation
of WW,WZ,ZZ in semihadronic channel.)
CDF 3.5 fb-1
9
10
CP in BS system
CDFDØ combined see 2.0s deviation from SM in
joint fit of DGS vs. fS for BS ? J/y f thus
hinting at new phenomena beyond the SM.
DGS GL GH 2G12cosfS
fS fSSM fNP fSSM -0.04 0.01
0.37 -0.33
Measure fS -0.76 rad (BS? J/y f)
Projection for BS ? J/y f only, 1 expt and no
projected improvements.
10
11
b-quark physics
August 2008
CDF 4.2 fb-1

• Tevatron produces heavy b-quark hadrons
  inaccessible at B-factories
• Have added to Lb(udb) seen by UA1 Sb (uub,
  ddb), Xb(dsb), Wb(ssb)
• (CDF DØ Wb masses do not agree)
• Extensive studies of BC, BS mesons

M6054.46.9 MeV
M616516 MeV
Increased statistics will improve mass, lifetime
measurements, BS mixing,. All are important for
confronting HQETpredictions and understanding
non-pQCD.
Rare b-hadron decays probe new non-SM physics. In
MSSM, BS?mm rate is enhanced by tan6b.
Expect 10xSM per experiment (10 fb-1).
M(mmKK)-M(mm)
And new surprises continue evidence for
charmonium state Y(4120) ?J/Y f ? mm KK (in
B?J/Y f K )
11
12
Searches for new phenomena
Neutralino/chargino search in trileptons
CDF and DØ have searched for many states expected
in Susy, strong coupling, large extra dimension
models with no clear signals to date.
Squark search in jet t MET

Search for c10 in GMSB with c10 ? G g.
Approaching the cosmologically favored region.
CDF
RS graviton ? ZZ
12
13
Searches for new phenomena
MSugra limits are improving beyond LEP limits,
due to high statistics and new techniques. For
example
We are gratified with these improvements
but we hear the locomotive coming on the tracks
behind us, and look forward to some real news on
SUSY soon.
13
14
New phenomena

• Now searching in new model contexts.
• In NMSSM, new light a states, with h ? aa (a?mm,
  tt) that defeat the SM H?bb search limits.
  HyperCP saw a hint of a 214 MeV a boson in
  S?pmm-. With full Tevatron sample, can exclude
  the NMSSM in much of the allowed range.

• Hidden valley models postulate a hidden sector
  weakly coupled to SM. SM Higgs couples to HV
  higgs pHV with couplings that could be large
  pHV ?bb. Get limits as f(MH, MpHV, decay length).
  Now exclude for small MHV, DL.

Neutralino can decay to HV dark photons and
darkino with gDARK ? lepton jets. Searches
now begin to exclude regions
of phase space.
14
15
QCD studies
Inclusive jet production to very large pT and
rapidity, favoring lower gluon content at large x.
Studies of pQCD and non-p QCD have extended HERA
and LEP measurements. The detectors and
algorithms are now well calibrated. Techniques
and PDF constraints are valuable for early LHC
running.
ds/dc distributions (would be flat for Rutherford
scattering) are sensitive to new physics
contributions. New limits set on quark
compositeness, RS extra dimensions, ADD extra
dimensions.
DØ data
ds/dMjj distributions at high mass and large
rapidity constrain PDFs.
15
16
Zjets production
W/Zjets production is an important test of QCD,
and is a major background for top quark studies
and many searches such as Higgs bosons
trilinear gauge boson couplings. LHC analyses
will require good understanding of these.
Recent studies of Zjets, unfolded from
pTjet(meas) to pTjet(true) to confront
predictions with various event generators. Jet
cone (R0.5) is used.
Meas vs true pT migration matrix
pTjet
yjet
pTZ
yZ
These comparisons generally show agreement within
errors for NLO pQCD (for pTZ gt 45 GeV). ALPGEN
shapes are OK, but normalizations are off.
SHERPA and PYTHIA have shape disagreements.
Zb jet measurements are key inputs for many
searches now being measured at the Tevatron.
16
17
SM Higgs boson
Low mass Higgs (MH lt 135 GeV) mainly sought in
associated WH/ZH production high mass (MH gt 135)
mainly in gluon-gluon fusion
March 2009 combination channels WH e/m n bb t
n bb qq tt e/m n W(e/m)W(e/m) jj bb ZH e
e/mm bb nn bb tt bb qq tt ttH lnb qqb
bb gg?H W(e/m)W(e/m) gg tt ( 2
jets) WW ?H tt ( 2 jets)
Mar. 2009 next update at Lepton Photon
17
18
SM Higgs boson
Direct Higgs search confronts the SM indirect
measurement allowed region.
The advanced multivariate and statistical
techniques used for the W/Z H search are now
verified in the similar W(ln) W/Z(qq) production.
Measure 20.24.4 pb (16.10.9 SM) 4.4s
significance. Would like to extend this to W(ln)
Z(bb) to also test b-tagging and lower
signal/background ratio.
18
19
SM Higgs boson

• Improvement faster than L-1/2
• better b-tagging
• lepton ID improvements
• more channels
• better background models
• larger kinematic regions
• jet E resolution improve

With 10 fb-1 analyzed, expect to be able to rule
out SM Higgs to gt180 GeV, and have shot at
evidence below 120 GeV.
Probability for 3s evidence in 10 fb-1.
19
20
SUSY Higgs
Previous searches for Susy higgs were in separate
channels. The sensitivities of these are
comparable
hb ? bbb
h ? tt
hb ? btt
New combined limit from all three processes 1
2.6 fb-1
Closing the gap on low mA Susy higgs in the
interesting region (tanb 35-40) where tanb
mt/mb
20
21
Conclusions

• We expect the delivered luminosity from the
  Tevatron to increase to 10 fb-1 (analyzed) by
  the end of the run, an increase by a factor of
  23. Analysis improvements will add also
  sensitivity. These allow substantial
  improvements for
• Low mass Higgs search
• W mass
• Diboson production
• Top quark mass
• Electroweak production of single top, Vtb
• Heavy b-quark states and CP violation in BS
• Resolving hints of new phenomena

Difficult for LHC
CDF DØ are running smoothly and efficiently no
indications of detector problems. Collaboration
strengths are sufficient to carry out the program.
We are having fun but feel like the warmup act
for the star performer. Good luck, and I hope
you blow us out of the water before long.