UK-CDF

Ronan McNulty (Liverpool)

on behalf of Glasgow, Liverpool, London, Oxford

Overview• Tevatron Operations• Hardware

– Layer00

– SVX

• Software– Silicon Monitoring and

Alignment

– Level 3 Trigger

– CDF Database

– Computing

• Physics Analyses– B physics

– Electroweak

– Searches

• Comments & Conclusions

Tevatron Operations

• Commissioning Run• 7 fills: Oct 8th – Nov 4th • Max lumi: 4x1029cm-2/s

with 36x36 bunches• 57.6nb-1 integ. lumi.• All detectors installed bar

Silicon. 6% proto-type instead.

• Level 1,2 & 3 triggers• Full DAQ

• Run II

• April 3rd 2001 LHC startup

• Max lumi: 7.9x1030cm-2/s

• 7.2pb-1 integ. lumi.

• Expect 2000pb-1

• CDF essentially complete

• Level 1 (2) 3 triggers

• Physics quality data

Layer 00• Layer00 is the silicon

detector closest to the beampipe. R=1.6cm

• UK designed & purchased the silicon.

• Designed and constructed the two 50cm long carbon fibre support structure and cooling.

• Irradiated and tested kapton cables

• Performed cooling studies

Carbon fibre prototype

Coolingchannel

Size ofBeampipe

Wide plaquettesSit here

Narrow plaquettes

Layer 00 construction

Narrow siliconmounted

Wide silicon mounted here

Hybrid

Assembly jig

Layer00 Performance

1/6 of Layer00 taking data (due to power supply delays)

Tracks observed in silicon Charge deposition in silicon

SVX

Two wedges of SVXImplemented for Commissioning Run

One of Three Silicon Barrelsinstalled for Run II.

SVX Testing

Performance of SVX

Correlation of charge deposited on n and p sides, for data taken with a ruthenium source

UK first to see beam profileCombined efforts of silicon expertise, database (pedestal update), and tracking algorithms led to first observation of the beam during Commissioning Run

SiliconLayers

Beampipe

Overlay of many events with pT>100MeVResiduals from Si

hitsto circle fit

cm

Silicon Monitoring

• Comprehensive monitoring tool

• Online: for rapid reaction to problems

• Offline: for detailed studies and record of performance over time

• Implementation:– Define quantities

– Create histograms

– Intuitive GUI

Barrel 0 Barrel 1 Barrel 2

R hits

R hits on

tracks

R v z for hits

on tracks

Silicon Alignment

Alignment vital for b tagging, B lifetimes, oscillations, CP violation, and searches

Perfect Alignment = 14m

Before =40m

After =15m

Impact Parameter (cm)

Impact Parameter (cm)

Impact Parameter (cm)

Level 3 Trigger

Level 3 Trigger

• Software Trigger (In 500Hz; out 75Hz)

• Fast event reconstruction on 250 CPUs.

• Operating since commissioning run• UK coordination and 24 hour support• Automated system for code validation• Regional tracking algorithms for full offline

reconstruction in selected detector regions

The CDF Database

• UK responsible for delivering the CDF database, online and offline.

• Acquire, store, provide information about the data and running conditions.

• Online: real time storage from hardware, run control, trigger, monitoring, calibration

• Offline: deliver to reconstruction and physics analysis.

• Coordinate consultants, schema designers, computer system experts, users.

The CDF Database• Start: structure insufficient

for expected size and usage• Poll hardware and software

experts• Implement new management

structure• End: 30GB database created

which handles 50,000 accesses/day. 99.8% up-time.

• Prototype database export system setup and in test between FNAL and UK.

5dbAdministrators

7C++/Oracle physicist

40Application programmers

500UsersTools

Computing

• Coherent UK strategy on computing

• >1Petabyte of data• £1.8m grant from JIF

– 4/5 for high-speed, high-volume disk

– 1/5 for networking

• Committed half so far– Universities & RAL:

8-way SMP server with fibre channel to 1TB RAID

– Universities at FNAL: 8 dual-processor PCs

– FNAL: 10TB RAID

Direct Contribution from UK to CDF

Accelerator Work

• Improve performance of Tevatron

• Several 10% improvements possible

• Request for effort• Optimise lithium lens

design (p collection)• Model production and

propagation• Create visualisation tool

for machine physicists

• Three UK technicians helping (travel paid by FNAL)

• One UK student (funded by FNAL)

Physics Analyses

• B physics: Lifetimes and Oscillations

• Electroweak Physics

• Searches: SUSY and Higgs

B lifetimes

• First measurements which CDF will perform in b sector

• Necessary step towards oscillation

• (Test of alignment, tracking, tagging.)

• Best measurement of Bs

0, b. (Unique)

HQET:

(B+ )/ (B0 )=1.05

( Bs0)/ (B0 )=1.00

(b)/ (B0 )=0.9 to 1.0

Experiment:

(b)/ (B0 ) is 0.78+-.04

B lifetimes

B lifetimeMillions of B mesons have already been produced in RunII.

Need to trigger and identify relevant decays. Leptons ‘easy’; hadrons difficult

Look for J/ Search for B+J/+

Run II data: tracks with Silicon hits

Run I data: UK thesis topic

Bs oscillations

PB(t) e-t(1+cos(m t))

• Lifetime measurements: prelude to oscillations

• For B mesons, Flavour eigenstates weak eigenstates

• So B0 B0

• Mixing parameter: x = m/

• LEP/Barbar: xd = 0.73

To date: xs > 14.6 Tevatron unique

• Usually measure by oscillating exponential; UK has developed new complementary method

B oscillations• m fL• Separate eigenstates and

measure each lifetime

1) BS DS+ DS

- (CP even) Work continuing in triggering on these difficult hadronic modes (track/vertex/reconstuct)

2) BS J/(CP even&odd)

Different angular distribution for allow separation of CP even and odd states

3) BS J/(CP odd)

B oscillationsSearch for BS J/UK Thesis with Run 1 data

Br.(BS J/)<8.75 x 10-4 at 90% c.l. (Prelim)

Electroweak Physics• Introduce new W and

Z simulations to CDF• Calculate systematic

uncertainty on W mass from higher orders.

• Conclude (2fb-1)– W mass to 30MeV

– W width to 40MeV

• Studying muon and electron identification

Electroweak Physics

Electroweak Physics

Z candidate

SUSY• Studying lepton spectra

for sensitivity to different SUSY models (eg. gluino pairs)

• Builds on electron/muon identification

• Specific search for chargino decays + 0

2 l

02 0

1 l l

• 3 leptons often enriched in taus

Higgs

Standard searches may exclude but not discover Higgs to 180GeV

Higgs search will be highlight of Run II for CDF/D0.

Higgs• Largest production

mode is gg H bb• …. but QCD

background enormous

• We can reconstruct bb with 10-15 GeV.

• …. Suppose we could reconstruct with 200 MeV

Higgs

Look in diffractive mode pp pHp

Reconstuct from missing mass of pp system

Large theoretical uncertainties exist as discussed at IPPP Durham last week. Theoretical & Experimental clarification required before proceeding to CDF approval or build.

CDF

55m

Higgs

UK CDF Personnel• Glasgow (2.6 FTE)

– S. d’Auria

– P. Bussey

– R. St.Denis

– S. Thomson

– 5 students

• Liverpool (5.9 FTE)– P. Booth

– B. Heinemann

– M. Houlden

– B. King

– S. Marti

– R. McNulty

– T. Shears

– A. Taffard

– 2 students

• Oxford (4.7 FTE)– F. Azfar

– T. Huffman

– J. Loken

– L. Lyons

– J. Rademacker

– A. Reichold

– P. Renton

– D. Waters

– 4 students

• UCL (2.1 FTE)– M. Lancaster

– R. Snihur

– D. Waters

– 3 students

Conclusions (I)

• Relativity small number of physicists: 15.3 FTE + 14 students

• High profile on experiment of 500 people• Very attractive to students and postdocs• Value for money

•Limited funding is having an impact on recruitment, profile and physics•Further to continual maintenance, we need to exploit out investment by producing physics.

Conclusions (II)• UK have delivered major components of CDF:

Layer00, Level 3 Trigger, Database.• UK coordinate/are responsible for: Database, Level 3,

Silicon Monitoring, Alignment• Understanding Detector: Silicon, Tracking, Muons,

Electrons• Physics Analysis underway: B physics, Electroweak,

Searches• Coherent UK hardware/software effort with common

data model (JIF) & common physics goals.