Hot Topics from CDF and D0 D.Glenzinski Fermilab ICHEP 2006 01-August

Hot Topics from CDF and D0

D.GlenzinskiFermilab

ICHEP 200601-August

01-Aug-2006 D.Glenzinski, Fermilab 2

Fermilab Tevatron

CellularField

Main Injector

Tevatron

DØCDF

Chicago

Wrigley Field • pp collider at world’s

highest energy

Ecm = 2 TeV

• Run-I 1990-1995 (110 pb-1 /experiment)

• Run-II 2001-2009 (6-8 fb-1 / exp expected)

• Performing excellently


Tevatron Run-II

• Data set has doubled every year

• ICHEP-04 Results : 200 pb-1

• ICHEP-06 Results : 1000 pb-1

2002 2003 2004 2005 2006

Del

iver

ed L

umin

osity

pb-1

(per experiment)


z

y

x))2/ln(tan(

Experiments: CDF

FeaturesFeatures:

• Precision silicon vertexing

• Large radius drift chamber (r=1.4m)

• 1.4 T solenoid

• EM+HAD Calorimetry

• muon chambers (|| < 1.1)

• Particle Identification


Experiments: CDF


Experiments: DZero (D0)

FeaturesFeatures:

• Precision silicon vertexing

• Outer Fiber Tracker (r=0.5m)

• 2.0 T solenoid

• EM+HAD Calorimetry

• muon chambers (|| < 2.0)


Experiments: D0


Tevatron Results Published

• From Run II:– 41 Physics publications by CDF– 33 Physics publications by D0– In 2005: 1 Tevatron publication every 7 days

• So far in 2006– Each experiment has ~15 Published+Accepted,

plus another ~15 submitted analyses

• At this conference– A total of 39 talks in parallel sessions


Tevatron Results at ICHEP-06• Parallel Speakers

– F.Canelli, A.Hocker, J.Nielsen, C.Hill, K.Hatakeyama, A.Kupco, M.Sanders, C. Schwanenberger, S.Blessing, M.Verzochi, G.Bernardi, D.O’Neil, D.Wicke, T.Moulik, M.Strauss, G.Borrisov, A.Nomerotski, S.Anderson, W.Taylor, E.Kajfacz, H.Greenlee, T.Hebbeker, P.Savard, I.Gorelov, B.Kilminster, E.Lipeles, M.Lancaster, A.Kraan F.Wuerthwein, P.Busey, R.Field, S.Giagu, S.Farrington, L.Pinera, M.Kreps, Y.S.Chung, A.Hamilton, A.Pronko, W.Wagner

• Plenary Speakers– R. Barlow “Rare B and Tau Decays”– E. Gallo “Beyond the Standard Model (Experiment)”– D. Wood “Precision Electroweak Results”


with 1 fb-

1

1.4 x 101

1 x 1011

6 x 106

6 x 105

14,0005,000

100 ~ 10

Pro

duct

ion

cros

s-se

ctio

n (b

arns

)

In 1 fb-1

Tevatron Physics Program(b)

• QCD• Heavy Flavor• Electroweak• Top Quark• New Phenomena

I Will discuss only a fewof the “Hottest” Results

• QCD• Heavy Flavor• Electroweak• Top Quark• New Phenomena


Hot Topics (Doug’s Opinion)

• Latest Bs Mixing Results

• Latest Top Mass Results

• Latest New Phenomena Results

Our raison d’etre Unique to Tevatron Program

Have significant impact


Bs MixingBs Mixing

D0 Results using 1 fb-1

CDF Results using 1 fb-1


B s

Bs

Bs Mixing: Motivation

• Bs particles can change into their anti-particles

• The rate at which Bs Bs oscillate : ms

• Important consistency check of CKM quark-mixing Matrix in Standard Model: ms ~ Vts


Bs Mixing: Basics

• Probability that Bs at t=0 decays as Bs at time t

• Experimentally, measure Asymmetry as a function of proper decay time

P(mixed) 1

2e

t

(1 cosmst)

A(t) # unmixed(t) - #mixed(t)

# unmixed(t) + #mixed(t)


Bs Mixing: Basics

Perfect Detector Actual


Bs Mixing: Ingredients

• For each event we need to determine

1)Bs or Bs at production?

1)Bs or Bs at decay?

1)Proper decay time

Signif NBD

2

2 e

(ms t )2

2 NB

N total

determined using “Flavor Taggers” D2

determined by reconstruction of Bs at decay t

determined by reconstruction of Bs at decay NB

mixedor

unmixed?


Ds , K*K ,

K K , K* K

Bs Mixing: 1) Identify Sample

• Bs is reconstructed via semi-leptonic decays

Bs Ds e, Ds

CDF 1 fb-1

Eve

nts

/ 0.

001

GeV

/c2

Ds mass [GeV/c2]


Bs Mixing: 1) Identify Sample

• Bs reconstructed via hadronic decays: unique to CDF

Bs Ds , Ds

Mass of Bs (GeV/c2)

CDF1 fb-1


Bs Mixing: 1 fb-1 Yields

# reconstructed Bs

D0 CDF

Semi-leptonic 36,500 37,000

Hadronic - 3,600

Next, determine proper decay time…


Bs Mixing: 2) Proper Decay Time

• Determine proper decay time from final state:

+

Ds-

LT

x

yproduction vertex

Bs decayvertex

LT MBs

PTvtx

+

determined from Monte Carlo (MC) simulation


Bs Mixing: Decay Time Resolution

• Hadronic decays have excellent proper time resolution

Semileptonic Decays

<> ~ 45 m

Hadronic Decays

<> ~ 25 m

proper decay time resolution () / cm


b

b

Bs Mixing: 3) Flavor Tagging

• B-Hadron Production at the Tevatron– Predominantly produced in bb pairs– b and b hadronize independently

Bd, B+, b, …

Bs

A) Opposite Side Tag (OST)

Infer production flavor knowing flavor of the other b in the event

B) Same Side Tag (SST)

Infer production flavor knowing flavor of fragmentation tracks

K-


Bs Mixing: 3) Flavor Tagging

• Flavor Taggers are characterized by:

• The effective statistics depend on these terms:

efficiency : dilution : D = 2(Purity) - 1

A(stat) ~ NB D2


Bs Mixing: Flavor Tagging

• Determining the dilution:

Bd, B+, b, …

BsB-For OST

Compare taggerdecision to knownflavor using fully

reconstructed B

For SST

Determined from MC. Validate MC usingreconstructed B

+

Dilution [%]


Bs Mixing: Flavor Tagging Performance

D2

D0 CDF

OST 2.5% 1.5%

SST - 3.5%

Total 2.5% 5.0%


Bs Mixing: Sensitivity

• “Sensitivity” = expected 95% CL upper limit on ms

• Determined from data

World 2006: 18

D0 2006: 17

CDF 2006: 25

ms Sensitivity (ps-1)


Bs Mixing: Measuring ms

• Look for evidence of Bs mixing using Amplitude Scan– Fourier transform to frequency domain

– Determine amplitude for fixed ms

– Scan ms : Amplitude = 1 at true ms, 0 otherwise

ms (ps-1)


Bs Mixing: D0 Results (Mar-06)

17< ms < 21 ps-1 @ 90% CL

PRL 97 (2006) 021802

1 fb-1

(Aug-06)

8% probability Random tags would look as significant

New! 50% more Bs

1 fb-1

For more details see the talk by T.Moulik.


Bs Mixing: CDF Results (Apr-06)

ms = 17.31 (sta) 0.07 (sys)0.2% probability Random tags would look as significant

CDF 1fb-1

hep-ex/0606027 (accepted by PRL)

For more details see the talk by S.Giagu.

+0.33-0.18


Bs Mixing: Constraints

• measured ms agrees with SM prediction

• relative precision of measured

ms)/ms = 1.5%

md)/md = 1.0%

• precision of measured ms is statistics limited

(syst)/ms < 0.5%


• use measured ms to constrain CKM

• agrees with SM prediction

• x5 more precise than previous determination

• limited by Lattice uncertainty


Vtd

Vts

= md

ms

mBs

mBd

0.208 0.0020.001 (stat) -0.007

0.008(theor)



For latest fit results see talks by S.T’Jampens, V.Vagnoni,and M.Bona


Bs Mixing: New Physics Constraints

• Use ms and CP violation in Bs sector to constrain New Physics contributions

– Bs sector largely unexplored

– Bs sector largely independent of Bd sector

– Bs sector more sensitive than Bd sector

• New Physics can affect ms and CP phase ()

BsSM ~ 1, Bd

SM ~ 20

ms = CNP msSM, Bs = Bs

SM + NP


Bs Mixing: NP Constraints

Bs = BsSM + NP

ms = CNP msSMConstraint from

ms, s, ACH

combined

XSM

CNPBs

NP(B

s) /

deg

rees

dark: 68%light: 95%

For decails see:hep-ph/0012219, hep-ph/0406300,

hep-ph/0605028, talks by S.T’Jampens and V.Vagnoni

• Recall


Bs Mixing: NP Constraints

Bs (rad)

New!

1 fb-1

SM

• CDF and D0 can also constrain

• D0 combines 3 measurements to get first constraints

• precision of all 3 are statistics limited

– more data to come– CDF + D0

• direct CP using flavor tagged decays

Bs J / For more details see the talk by G.Borissov.


Top-Quark MassTop-Quark Mass

D0 Results using 0.4-1 fb-1

CDF Results using 1 fb-1


Top Mass: Motivation

• Mt is a fundamental parameter of the Standard Model

• Since Mt is large, quantum loops involving top quarks are important to include when calculating precision observables (e.g. sin2w, Rb, Mw,…)

• Within SM, particularly important to help constrain MH

W Wt

b

H Ht

t

Zt

t

b

b

W


Top Mass: Motivation

• Mt important input for any model trying to describe high energy particle physics

– In MSSM at tree level: Mh<Mz (very excluded)

w/ Mt loop corrections: Mh < 135 GeV

– Mt impacts soft-SuSy breaking phenomenology

– Mt plays critial role in verifying gauge unification through RGEs

• Precision Mt crucial to understanding underlying theory of HEP, whether SM or SuSy or …


Top Mass: Basics

• Top quarks predominantly produced in pairs via the strong interaction

• Production cross-section: ~ 7 pb at Tevatron

q

q

t

t 85%

t

t

g

g15%


Top Mass: Basics

• Because Mt > Mw + Mb, and Vtb>> Vts,Vtd

• Final state determined by W decays

(top) ~ 1

10 (hadronization)

BR(t W b) ~ 100%

tt W bW b bb “Di-Lepton”

tt W bW b q q bb “Lepton+Jets” “All Jets”

tt W bW b q q q q bb


Top Mass: Basics

• We measure Mt in each of these final states

– Dilepton (DIL)

– Lepton+Jets (LJT)

– All Jets (AJT)

• Compare across channels for consistency

• Combine all channels for improved precision


Top Mass: Ingredients

• To measure Mt we need to:

1)Collect top quark sample

2)Reconstruct observable sensitive to Mt

3)Unfold experimental effects

Mreco (EW ,p W )2 (Eb,

p b )2

Mreco M t


Top Mass: 1) Collect Sample

• Dilepton: ttllbb2 high energy leptons, missing energy (), 2 jetsIn 1 fb-1: #signal~50, Purity~65%

• Lepton + Jets: ttlqq bb1 high energy lepton, missing energy (), 4 jets (1 Bjet)In 1 fb-1: #signal~230, Purity~90%

• All Jets: ttqq qq bb 6 jets (1 Bjet)

In 1 fb-1: #signal~200, Purity~30%

For more details see talks by C.Hill and D.O’Neil


Top Mass: 1) Collect Sample

• cross-sections and kinematics agree with Standard Model

tt production cross- section (pb)

For more details see talks by D.Wicke, A.Kraan, S.Anderson


Top Mass: 2) Event Reconstruction

tt W bW b q q bb

Have

Jet 1Jet 2Jet 3Jet 4

LeptonEt

Need

qq’bb

Lepton

?

Combinatoric Background

Have Jet EnergiesNeed Parton Energies

“Jet Energy Scale”(JES)DIL : 2 combinationsLJT: 12 combinationsAJT: 90 combinations


Top Mass: 2) Reconstruction

Jet Energy Scale == Absolute Mass Scale

M(qqb) / GeV/c2

UncorrectedCorrected

Monte CarloMt = 175 GeV/c2

• hadronization, non-linearities, pile-up, multiple-interactions, underlying event

• From Data and MC

• known to ~3% for Mt

jet energies

• Leading Run I syst

• Reduced in Run II


Top Mass: 2) Reconstruction

• Run II analyses further constrain JES

– In-situ constraint possible by comparing observed

Mqq to known Mw (in LJT and AJT channels)

– with 1 fb-1, reduces (JES) systematic by factor of 2

(JES) will scale with sample statistics

tW

b

q

qMqq = Mw


Top Mass: 3) Unfold Exp Effects

• Use detailed Monte Carlo to unfold experimental effects and determine Mt from Mreco

m(reco) GeV/c2

“data”

Lepton+Jets ChannelDilepton Channel

true

Mt

measured Mt


Top Mass: Results

• Excellent results in each channel

• Combine all CDF+D0, Run-I+Run-II

• Account for all correlations

• Uncertainty:

Mt(stat) = 1.2

Mt(JES) = 1.4 GeV/c2

Mt(syst) = 1.0

Stat+JES scale with sample sizeMt determined to 1.2%!

(cf. http://tevewwg.fnal.gov)

New!


Mt(jes)

(Signal)(Bgd)

(Other)

(syst)(stat)

(total)

170.9

174.0

164.5

LJT AJT DIL

the most precise result in each channel

Top Mass: Results

Jet Energy Scale is leading systematic in all channelsISR, FSR, PDF, NLO effectsComposition, Normalization, and ShapeMC statistics, Method, B-tagging, etcuses in-situ JES calibration comparing Mqq to MwSingle most precise determination

For more details see talk by F.Canelli

(in units of GeV/c2)


Top Mass: Results

• The channels are consistent at 15% level


Top Mass: Future

• Extrapolations based on present methods– Solid: pessimistic– Dash: optimistic– Reality: in between

• Have surpassed Run-II goal

• TeV will measure Mt with <1% precision


Top Mass Constraints

• Indicates Higgs is light, where our sensitivity best!


New PhenomenaNew Phenomena

Where do we stand?

Where will we go?


New Phenomena: Motivation

• The Standard Model – is an effective (low Energy) theory– does not include a description of gravity– has shortcomings

• There could be something more… but what?– SuperSymmetry (mSuGra, GMSB, SO(10),…)– Compositeness, 4th Generation, LeptoQuarks– Extra Dimensions, Technicolor

• We look for all of these things


Searching for

(thanks to Mark Oreglia)

the Higgs Boson

• Higgs required to generate W, Z masses

• Precision EWK prefers light Higgs

• Most SuSy needs 1 light Higgs


Higgs: SM Production

• For MH=140-110: (WH+ZH)=100-300 fb

• For MH=180-140: (ggH)=150-500 fb


Higgs: MSSM Production

(MSSM/SM) = 1-100 depending on Susy parameters; Tevatron sensitive to large tan

=h,H,A


Higgs: Decay

• In SM most important higgs decays are

• In Susy most important higgs decays are

h bb , + , W W

h bb , +


Higgs: Experimental Signatures

• Experimental final state determined by W, Z decays

• The most important for the SM Higgs are

• Each experiment has results in all of these final states

WH ebb , bb

(W)H (W)WW* X, X

ZH e+e-bb , -bb

ZH bb

For more details see talks by B.Kilminster, A.Hocker, and G.Bernardi


Expected sensitivity within factor of5-10 of SM for all 110 < MH < 200!

Additional sensitivity from more data, and application of known improvements to all channelsA lot of work - but we will reach SM sensitivities

New! CDF WH,ZH with 1 fb-1

Important at low mass

Differences in single expsensitivity owing to these

luminosity differences

Higgs: Limits

• We combine ~15 CDF+D0 results (250-1000 pb-1)New! D0 ggH, WH with 1fb-1

Important at high massCDF/D0 updates comlimentary

Tev expected = Single experiment @ 1.3 fb-1

(cf. http://tevnphwg.fnal.gov)


Higgs: MSSM Sensitivities

Tevatron will have sensitivity to MSSM higgs for all tan>30 and MA<200 GeV/c2


Higgs: Progress

SM cross-sections for (di)boson production

CDF 72 pb-1

We~35k evt

D0 96 pb-1

W~xxk evt

Have >106 leptonic Ws in 1 fb-1Tau identification well understood.

D0 177 pb-1

Z e+e-

CDF200 pb-1

Z +-

We have ~105 leptonic Zs in 1 fb-1We have ~103 W,~102 Z in 1 fb-1

W+W -

We have ~102 WW in 1 fb-1

WZ

We have ~10 leptonic WZ in 1 fb-1

• with 1 fb-1 we’re observing cross-sections of order 1 pb in final states similar to SM H

• expect a factor of ~8 more data

• experimental sensitivity on track and will get better

– extended b-tagging– improved jet resolution

• CDF and D0 enthusiastically pursuing the Higgs


Conclusions

• Tevatron performing well

– 1 fb-1/experiment in hand

– Expect 6-8 fb-1/experiment by end 2009

• CDF and D0 performing well

– Publishing wide spectrum of world class results (CDF+D0 2005 avg: 1 published paper/week)

– Ready to take advantage of coming data

– Enthusiastically pursuing New Physics and Higgs


Conclusions

• The LHC will inherit

– Precise determination of ms and constraints on CP phase in Bs sector Bs

– Precision Mt (Mt=1.0-1.5 GeV/c2) and

Mw (Mw=15-25 MeV/c2)

– A more restricted New Physics parameter space

– A higgs mass


Backup Slides


Bs Mixing: Decay Time Resolution

(semi-leptonic) depends on decay time


Bs Mixing: Likelihoods CDF

Final significance and measurement of ms using Lhood ratio

logL(ms,A 0)

L(ms,A 1)

min = -6.75


Bs Mixing: Likelihoods D0

Resolution K-factor variation BR (BsDsX) VPDL model BR (BsDsDs)

Mar-06

D0 Jul-06

Systematics


Bs Mixing: D0 A-Scans for New Modes

Ds K*K

BsDs XBsDs (e X

Ds

Documents

Hot Topics from CDF and D0 D.Glenzinski Fermilab ICHEP 2006 01-August