UK-CDF Ronan McNulty (Liverpool) on behalf of Glasgow, Liverpool, London, Oxford
Mar 28, 2015
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.