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 8 th – Nov 4 th Max lumi: 4x10 29 cm -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 3 rd 2001 LHC startup Max lumi: 7.9x10 30 cm -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 Cooling channel Size of Beampipe Wide plaquettes Sit here Narrow plaquettes

Layer 00 construction Narrow silicon mounted Wide silicon mounted here Hybrid Assembly jig

Layer00 Performance 1/6 of Layer00 taking data (due to power supply delays) Tracks observed in siliconCharge deposition in silicon

SVX Two wedges of SVX Implemented for Commissioning Run One of Three Silicon Barrels installed 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 profile Combined efforts of silicon expertise, database (pedestal update), and tracking algorithms led to first observation of the beam during Commissioning Run Silicon Layers Beampipe Overlay of many events with pT>100MeV Residuals from Si hits to 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 0Barrel 1Barrel 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 = 14 m Before =40 m After =15 m Impact Parameter (cm)

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. 5 dbAdministrators 7 C++/Oracle physicist 40 Application programmers 500 Users Tools

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 B s 0, b. (Unique) HQET: (B + )/ (B 0 )=1.05 ( B s 0 )/ (B 0 )=1.00 ( b )/ (B 0 )=0.9 to 1.0 Experiment: ( b )/ (B 0 ) is

B lifetimes

B lifetime Millions 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 P B (t) e - t (1+cos( m t)) Lifetime measurements: prelude to oscillations For B mesons, Flavour eigenstates weak eigenstates So B 0 B 0 Mixing parameter: x = m/ LEP/Barbar: x d = 0.73 To date: x s > 14.6 Tevatron unique Usually measure by oscillating exponential; UK has developed new complementary method

B oscillations m f L Separate eigenstates and measure each lifetime 1)B S D S + D S - (CP even) Work continuing in triggering on these difficult hadronic modes (track/vertex/reconstuct) 2)B S J/ (CP even&odd) Different angular distribution for allow separation of CP even and odd states 3)B S J/ (CP odd)

B oscillations Search for B S J/ UK Thesis with Run 1 data Br.(B S J/ )<8.75 x 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

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 – l – 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 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. dAuria –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.