The CDF Group at LBNL

LBNL Director Review, November 8-9, 2006

Angela Galtieri

1

Status of the Tevatron

LBNL Group

CDFII Detector

Contributions to CDFII

Hardware

Operation

Recent Contributions to Analysis Tools

Physics Program

B physics

Top Physics

New Phenomena

Summary and Conclusions

Outline

2

Tevatron Status and Plans

Tevatron has been doing very well.

Record luminosity: 2.37x1032

Needs to improve pbar stacking rate to 30 mA/hr to stay on the Design curve

Presently have processed 1.2 fb-1 good runs with Silicon

2.0 fb-1 delivered

1.6 fb-1 to tape

March 2006

3

Members of the LBNL Group

Physicists-Staff (2.0FTE)

A. Galtieri

J. Beringer***

C. Haber*

J. Lys *

M. Shapiro* (UC Berkeley)

J. Siegrist* (UC Berkeley)

W. Yao***

Physicists-Term (3 FTE)

A. Cerri (now CERN )

J. Nielsen (UC SantaCruz)

P. M. Fernandez

Grad. Students(5.0FTE)

A. Gibson (Toronto)

H-C. Fang

J. Freeman

P. Lujan

A. Deisher

J. Muelmenstaedt

Undergrad. Students (1FTE)

M. McFarlane (now grad. at Wisconsin)

*ATLAS, ** PDG

FTE refer to FY06

Guest

I. Volobouev (Texas Tech)

It is unfortunate that after 25 years of contributions to CDF, LBNL's group is

disappearing when the data finally arrives

4

Physicists-Staff (2.0FTE)

A. Galtieri

J. Beringer***

C. Haber*

J. Lys *

M. Shapiro* (UC Berkeley)

J. Siegrist* (UC Berkeley)

W. Yao***

Physicists-Term (2 FTE)

A. Cerri (now CERN )

J. Nielsen (now UC SantaCruz)

CDF recent upgrades

Improved photon detection

EM calorimeter: timing readout added

Central preshower: wire chambers replaced with scintillation tiles

DAQ upgrade

To match the trigger: 20MB/sec -> 60 MB/sec

Trigger Upgrade

30KHz(L1), 1KHz(L2) 100Hz(L3)

XFT: fast tracking trigger added 3 stereo layers

LBNL Contributions to: Silicon detectors, COT, TOF

Commissioning, Operation, Software

CDFII Detector

Forward

muon

Endplug

calorimeter

Silicon and drift chamber trackers

Central muon

Central calorimeters

Solenoid

TOF

5

Silicon Detectors:LBNL Contributions

SVX’

1990

SVX2

1996

SVX3

1998

SVX4

2002

LBNL designed SVX, SVX'.

Joint designs with FNAL since.

SVX3 used in CDFII RUN 2b R&D and prototyping

SVX4: developed for Run 2b Project canceled due to budget cut. Chip used by D0, Phenix at BNL

Conversion to .25 micron CMOS technology proposed by LBNL. Also used by ATLAS' pixel chip

Hybrids and “stave” (new detector concept : integrated electrical, mechanical and cooling unit) being evaluated by ATLAS

Silicon detectors transformed physics capabilities of CDF since early '90.

LBNL is a major player in Vertex Detector technology. Long standing tradition, now extended to LHC.

SVT, displaced vertex trigger

Extended B physics capability

Rad hard chips for Silicon Detectors

6

Silicon detectors transformed physics capabilities of CDF since early '90.

LBNL is a major player in Vertex Detector technology. Long standing

tradition, now extended to LHC.

LBNL Contributions to CDF II

I. Construction

Silicon detectors

SVX3 chip (co-design with FNAL), test, probe

hybrids for L00, SVXII, ISL

associated electronics

Drift Chamber (COT)

inner cylinder, field sheets

Conceptual design of alignment

Time calibration system

II. Commissioning

COT Associate Project Manager

COT Commissioning

Silicon commissioning

III. Operation

CDF II Operation Manager

SVT operation

Silicon Operation

IV. Computing and software

Project manager

Codegen for relational data bases

Data handling software for early tests

Silicon Code librarians

TOF

Study laser calibration system

Install fibers, online monitoring

7

LBNL Recent Contributions to CDFII

Silicon good run list (P. Lujan)

SCI-Co or CO shifts (everybody)

moved to other groups

Online silicon monitoring (to John's Hopkins)

Silicon calibration ( Nielsen)

Online data monitoring (YMON) (to Rochester))

COT calibration (to FNAL)

SVT data taking: pager (to Pisa)

SVT online monitoring checks, SVT hardware support, upgrade code consultant (A. Cerri)

DAQ shifts (3 months service)

Detector Operation (MOU)

GFLASH tuning (P. Fernandez) moved to other groups

MC generators : ISAJET (Galtieri), HERWIG, Wbbgen (Lys), ZGRAD (Gibson)

Silicon geometry (A. Dominguez)

Passive material (L. Vacavant)

Silicon Tracking (W. Yao)

Secondary vertices code (W. Yao, A. Dominguez)

SVT simulation (A. Cerri)

MC: EVTGEN, B decays generator (J. Beringer)

Software Responsibilities (MOU)

LBNL Contributions to CDF II

8

Displaced vertex b-tagging (SECVTX)

M. McFarlane, J. Nielsen, W-M Yao + others

Displace vertex agorithm important for tagging b quarks products. B physics, top physics, Higgs etc.

tt event efficiency = (60±3)%

Efficiency for second tag in top events (25±2)%

Efficiency ratio between data and MC (91± 6)%

Displaced vertex algorithm allows detection of b quarks, important for B physics, top, and Higgs



xy~150 

Combine SECVTX (reconstructed

secondary vertices) with

JetProb (single displaced tracks).

Improved efficiency by ~25%

adding jets that were not tagged

Reduced backgrounds from c and light quark jets by ~fac. 2

Retain 90% of b-tags

light q jets-b jets

charm jets-b jets

NN improved tagging efficiency.

95% b effic.

95% b effic.

9

Jet Corrections and systematics

Pedro Fernandez, L. Galtieri + others

NIM A566, 375 (2006)

Long standing expertise on jets in LBNL group

Run2 systematic uncertainties (published in NIM ) are now smaller than Run1.

Recent calorimeter simulation tuning (P. Fernandez)

Special trigger provided large samples of isolated tracks to 40 GeV/c (from 5 GeV/c)

Lateral and longitudinal tuning of central and plug calorimeters almost finished

Plug tuning helped reduce W mass systematic uncertainty

Expect to reduce jet energy systematics by at least 30%

Central , before tuning

Plug , before tuning

after tuning

almost final

10

B Physics: where are we?

Bs mixing is best measured with fully reconstructed decays to reach high values of xs . Partially reconstructed decays modes are also used.

Initially Bs semileptonic decays , high statistics, were used

CDF has measured Bs mixing in 2006 .

CP violation in the B system constrains the unitary triangle.

SM requires α+β+=, Sin2β well measured at the B factories.

SVT (Silicon Vertex trigger) allows study of the hadronic decays B→hh , Bs→ Ds π etc.

It opened a whole new window that can lead to new physics

Bs physics can only be done at the Tevatron

Vcb

11

CP violation in Bs  J/ is new physics

Bs mixing

BsKK,

Bs Mixing at CDF

md = 0.507 ± 0.005 PDG-06

SM Fit: Δms = 18.3 ps-1

To measure CPV in the Bs system we need to measure Δms from Bs-Bs oscillations. Amix ~Dcos(Δmst)

Δms expected to be large due to coupling to top quark

Bs fully mixes in < 0.15 lifetimes !!

−

B mixing measurements : ∆ms ≥14.5 ps-1, LEP and SLD data

17 < ∆ms < 21 ps-1 2006 D0 PRL 97,021802

∆ms=17.31 ±0.07 ps-1 CDF PRL 97,062003

12

+6.5

-1.5

 = 1.21

+0.047

- 0.035

Okamoto-05

+0.33

-0.07

Bs mixing Analysis (I)

Lxy mB

pT

ct = K

Procedure

B Reconstruction

hadronic: good pT resolution, small statistics

semileptonic : bad pT resolution, large statistics

Tag flavor at production (calibrate with Bd)

Measure time dependent asymmetry

N(t)mixed -N(t)unmixed

N(t)mixed +N(t)unmixed

A(t) =

= Dcos(Δmst) where D=1-2Pmistag (dilution)

D2 : crucial for high significance ( : fraction of events with flavor tag).

13

K factor for partially reconstructed Bs

significance:

Bs mixing Analysis in 1 fb-1

Bs-> Ds─ π, Ds─ φ π─

Bs -> Ds, Ds  K*K

Use NN for event selection, including TOF and dE/dx (reduce background, improve efficiency)

Many tagging techniques: opposite side tagging (including kaons), same side tagging (also NN)

Include partially reconstructed B's (K factors). Optimize proper time resolution.

Obtain: D2 = 4.8% semileptonic (61500 ev.) D2 = 3.7% hadronic (8700 events)

14

Bs -> Dslep., Ds  K*0K+

Bs mixing results (1 fb-1)

Perform an Amplitude Analysis ℒ ~ [1±ADcos(mst)]/2

15

Bs mixing is observed!

A= 1.21 ± 0.20 (stat) consistent with 1.

Probability of random tags to produce

this result is p = 8x10-8 → 5.4 σ

Δms= 17.77±0.10(stat) ± 0.07(syst) ps-1

Likelihood for Δms

(all modes)

Oscillations Period

(hadronic modes only)

Several contributions from the LBNL group

agrees with SM prediction: no New Physics

Bs switches between matter

and antimatter 3 trillion times/sec

Bs mixing with Fourier Transform

Comparison with standard amplitude scan

Bs oscillations are a periodic signal: Fourier space is the natural tool

Fourier transform of data: g(ω)=Σk cos(ωtk)

(tk = proper time event k)

Difference of g(ω) for unmixed and mixed events: Δ(ω)

Peaks for ω=Δ ms and is 0 everywhere else

Same sensitivity as fit based Amplitude scan

Can relate Δ(ω) to fit based Amplitude

Very fast computationally (no fit!)

Analysis tool has been developed and validated against standard method (1/10 of data)

Largely systematics free approach opens novel route towards search of CP violation signals in Bs oscillations (e.g. in Bs)

ω=Δ ms

Δ(ω

A. Cerri, M. Shapiro, A. Deisher, H-C Fang, J. Muelmenstaedt +others

16

LBNL Present Program

A. Deisher, H-C. Fang, J. Muelmenstaedt, M. Shapiro

3 PHD thesis : Bs lifetime BR(B+→ D0K)/(B+→D0π) BR(Bs→ DsK)/(Bs→ Ds π)

Common code, common Monte Carlo etc.

Control samples: B0 → D* X B0 → D+ X

Understand common inputs: Event selection cut optimization Particle ID : dE/dx Background model studies Systematics studies

Mass fit results used in lifetime measurement

17

B0→ D* +X

Control sample (410 pb-1)

Simultaneous fit of

D*+π- mass and dE/dx for each track

Bs Lifetime measurement (1fb-1)

Amanda Deisher (PHD thesis), M. Shapiro, H-C Fong, J. Muelmenstaedt

18

Motivation: theory experiment

(Bs)/(B0) 1.00 ± 0.01 0.914 ± 0.030

(Bs) = 1.466 ± 0.059 ps (PDG)

(Bs) = 1.60 ± 0.10 ± 0.02 ps (CDF 360 pb-1)

Use all hadronic decay modes

Add new hadronic modes, Partially Reconstructed (PR) modes , more data

Developing method on B0 control sample: get good mass fit (sample composition) get K factors for PR samples

Results on control sample: c = 461.4 μm (signal region) c = 464.8 μm (PR region)

Going to Bs sample after control sample measurement is completed.

Control sample

B→ D+ X

c (B0) = 458.7 ± 2.7 μm

World Average, PDG

+9.7

-9.4

+12

-11

Cabibbo suppressed B¯ Do K¯

Motivations: measure the angle  , via three branching ratios:

BR(B¯  Do K¯)/BR(B¯ Do ¯) and

BR(B- DoCP± K-) /BR( B-DoCP± ¯)

H-C. Fang (PHD thesis), M. Shapiro, A. Deisher, J. Muelmenstaedt

Direct CP-violation in B DCP± K (M. Gronau, PRD 58, 037301) predicts

B- DoCP± K  B+ DoCP± K). Model allows extraction of the angle 

Selection optimized for B-  Do K­

Extend analysis to 1 fb-1, after fits to control samples are satisfactory.

Small background

ND0π = 8054± 101

Ns ~ 670

M (Do ¯) GeV

Use dE/dx for - separation

1.4  at P ~ 2 GeV

Obtain templates from known processes

19

DoCP+ K+K-, π+π-

Measurement of BR(Bs Ds K)

20

Johannes Muelmenstaedt (PHD thesis), M. Shapiro, A. Deisher, H-C Fang

Measure BR(BS DS K)/BR(BS DS π) DS K sample is already available

Need to understand control fit of dE/dx + mass

b

s

u

s

s

c

Vub~Aλ3

Vcs~1

b

s

c

s

s

u

Vcb~Aλ2

Vus~λ

There are two processes. They have comparable amplitude, relative phase .

Bs oscillations can cause interference between the two amplitudes

Bs-> Ds─ π, Ds─ φ π─

Time dependent CP asymmetry measurement needed to measure 

Measure top quark properties

Mass to 2 GeV, Top cross section to 10%

Verify SM decay properties

Any non SM processes hide in top events?

Higgs production

SM Higgs: it is a big challenge, but try

SUSY: tanβ=50 5σ discovery possible of H/A with M=175 GeV (8 fb-1)

Pre8sion Measurements

Electroweak Precision Measurements

Design

luminosity

SUSY:

Some of the parameter space for squarks and gluinos are being explored.

Long lived stable particles , trileptons, etc. Many ways to search

Many other searches: W'. Z', leptoquarks ,

technicolor, extra dimensions etc.

Prospects for High PT physics at CDF

21

Top Quark Property Measurements

Top events preferentially in W+ ≥ 3 jets

W + JETS

p

p

g

q

q’

t

t

t t Production at the TeV:

Top quark is heavy: decays very fast!

(t -> Wb ) ~ 1.5 GeV, t=4x10-25sec

ΛQCD = 100 Mev, Λ-1 = 10-23 sec

No hadronization: no top mesons or baryons

6 jets

l + 4jets

2l + 2jets





e

Final states (2 b-jets + 2 W):

- dilepton (2 W❐l)

- lepton+jets (W❐l,W❐qq)

- all hadronic (2 W❐4q)

Lepton + jets channel preferred: statistics advantage over the dilepton, less backgr. then the all hadronic

2/3 signatures: lepton and ½ b jets

t t W+ b W- b

Strategy:

Understand the top candidate sample: b-tagging, backgrounds, agreement between data and Monte Carlo etc.

Optimize tools for σ, mass, W helicity etc. measurements.

Look for deviations from SM

22

Fernandez, Freeman, Galtieri, Lujan, Lys, McFarlane, Nielsen, Yao

Top Cross Section Measurement

/

Understanding top candidates sample, to be used for all other top studies

LBNL: use lepton+jets channel, b-tagging to reduce background.

McFarlane, Nielsen, Yao, Kusakabe(Tsukuba) + others

Double tagged top event

Sample selection:

Isolated lepton, PT > 20 GeV

MET > 20 GeV (neutrino)

N (jets) ≥ 3 jets

≥1 b-tag by the SVX algorithm

Background : use N(jet) = 1,2 to check background calculations

Mistag

non-W QCD

Physics background: Wbb, Wcc

Single top, WW, WZ etc.

Winter '06, 695 pb-1

−

23

Top Cross Section (cont.)

Require, HT (total transverse energy ) > 200 GeV to reduce background

HT

CDF winter '06 averages use 750 pb-1

314 tagged events, 79 with 2-tags

(70 ± 8 back.)

HT

Lxy (mm)

24

Top Quark in the Standard Model

The Standard Model predicts the Higgs mass, once the W and Top mass are measured with high precision.

Loop corrections to MW proportional to Mt2 or ln( MH)

Summer 2006 World average:

M(top) = 171.4 ± 2.1 GeV (CDF+D0 Run I+II)

July 2006 best Fit

M H = 85 GeV

old:

now

MH< 166 GeV

at 95% CL

Direct limit:

MH > 114 GeV

at 95% CL

25

+39

-28

Top Mass: new LBNL analysis

For each event evaluate a likelihood as a function of the top mass and JES . Integrate over phase space (d Φ) and Matrix Element for top prod. and dec.

See Kondo (JPhys. Soc. 57,1988), Dalitz&Goldstein(Proc. R. Soc. Lond., A445,1999).

measured quantities Incoming partons parton level quantities.

Fernandez, Freeman (thesis), Galtieri, Lujan, Lys, Nielsen,Volobouev

JES (Jet Energy Scale): to transfer systematic to statistical uncertainties.

w( y,JES| x): Jet transfer functions to improve resolution

Introduce effective propagators to take into account jet masses and angular smearing, on event-by-event basis

Introduce a

back./signal

discriminant

to reduce

back. effects

Unique Features

26

LBNL Mass analysis (cont.)

Integration done over 7 variables. All jet permutations used.

Reconstructed-vs-true mass has slope = 0.99±0.01 and bias=0.4 GeV for signal only

Present data (955pb-1):116 events with 4 Jets (PT>15 GeV), ≥ 1 b-tagged jet.

Expected background = 18 ± 4 events

2-D likelihood: mass -vs -JES allows reduced JES systematics

Present results based on MC : cannot look at data until our model is optimized.

Pseudo-experiments (MC) predict mass uncertainties larger than expected (pulls ~ 1.3) Working on improving the model.

Method being reviewed by the collaboration

27

Search for new signals in W bb events

Techniques developed in Top analyses can be

used for other searches, for example:

pp  W X with X  bb

Higgs  bb, SM cross section too small for observation in current data

Understand backgrounds, develop better tools, increase acceptance etc.

J. Nielsen,W-M Yao, + Tsukuba U. + Waseda U.

Use top sample events with a W and 2 jets (at least one tagged jet). In 955 pb-1, observe 421 events, expect 394±67 background events

Calculate limit for Higgs production-vs-mass.

−

−

−

−

28

−

M(bb)

Cross sections for technirho production

T WpT , pT bb

are an order of magnitude larger. 95% CL limit

Higgs Search at the Tevatron

CDF and DO limits (Yao et al.), ICHEP06.

Combination of 11 measurements: 4 use ~1 fb-1, 7 use ~ .3 fb-1

Factor 10 off for M<140 GeV/c2 “ 5 “ M ~ 160 GeV/c2 By end of 2008, expect ~10 times the data.

Working on increasing the sample Trigger task force: increase triggers used

Analysis improvements list (October 05 )

Many tools available, have to be included in the analysis of the different channels

LBNL b-tagging separate 1 and 2 b-tag, + NN: ~ 30% sensitivity improvement.

Forward tracking being improved

NN Event Selection being investigated

CDF is moving towards a strong effort on the Higgs search

29

The Road to the Higgs

30

Summary and Conclusions

Large contributions to hardware and physics over the last 25 years Trained 15 PHD thesis, 21 postdocs. 21 of these have faculty or lab staff positions.

Contributed to top discovery, precision top and W mass measurements, particle searches, properties of B mesons, Bs mixing

LBNL still contributing to Run II CDF physics results:

CKM Parameters, Bs Mixing

Top Physics

New particle searches

Data sample expected to be ~ 40 times the Run I data by end FY07.

Better statistics, improved analysis tools.

Window of opportunity for high PT physics before the LHC.

Unfortunately, the LBNL group is dwindling in size!

31

DOE LBNL Presentation 2006

Backup Slides

32

Contributions to Analysis Tools 2005-6

EVTGEN: improved B decays simulation (Beringer)

Trigger efficiency for electrons (for all High PT physics groups)

Improved offline code, Gen5, and validation for top group analysis.

Validate Gen6 using W cross section data (Freeman,Nielsen)

Improved Scale Factor (data/MC) for electron ID (McFarlane, Yao)

Trigger studies for B physics (improve Bs mixing measurement)

Improved impact parameter resolution (better Bs mixing sensitivity)

Silicon b tagging high PT (efficiency, scale factor, NN)

Jet corrections and systematics (smaller systematics on top mass)

Exploit group expertise to optimize data taking and detector performance.

Develop reliable tools to perform physics analysis.

Essential for precision measurements.

33

34

New results

Top mass average of best results of CDF and D0.

All correlations taken into account.

Mtop= 171.4 ± 2.1 GeV/c2

dMtop= 1.2% Mtop

δM(stat) = ± 1.2 GeV/c2

δM(JES) = ± 1.4 GeV/c2

δM(sys) = ± 1.0 GeV/c2

Values obtained from 3 different channels agree at the 15% level

(Glenzinski, ICHEP06)

Top Mass results: July '06

Need to improve

Lina Galtieri, CDF, Director Review 11/08/06

2002-04-21T14:25:46