T. Bowcock1 Can CP save life? LHCb and its applications…

T. Bowcock2 Overview CP physics and the LHCb experiment LHCb vertex detector technology Optimization MAP project Applications Summary

T. Bowcock3 CP z x y P:P: C :(particle antiparticle) CP violated only rarely … compensated by T violation (CPT) e.g K L e ± ±

T. Bowcock4 Why study CP violation? Origin of CP (T) violation? –Matter/AntiMatter Asymmetry Sakharov CP violation –Only observed in K system. –CP effects in B system in SM Cosmology Particle Physics

T. Bowcock5 CP studies 1st Generation B -sector studies <2005. Two possibilities: –either: there will be already a sign of new physics –or: measurements will look consistent with the Standard model. A dedicated experiment at LHC is needed. A CP-interferometer. About 10x more sensitive.

T. Bowcock6 CP studies B d + - B d s B s D s K B s mixing V ub /V cb B s First generation of experiments will study V ub /V cb and B d K s. To study all angles/decay modes need a specialized detector. Detailed B s studies out of reach of Generation 1 experiments. B d J S B s J B s D S K (PID) B d DK (PID,Trigger) B d D* (PID) B d (PID) B d K (PID) B d B s K B s K l l B s B s LHCb ATLAS/CMS

T. Bowcock7 B-hadron production 32 2 CP effects 10K events About BB produced/year (10 8 Gen. 1)

T. Bowcock8 LHCb Detector

T. Bowcock9 Vertex Detector Precision tracking that: –identification of B vertices –measurement of lifetime (40fs) B s D s K

T. Bowcock10 Geometry 10cm Detectors separated 6cm during injection series of 17 1/2 disks small overlap Positioning and movement to 5 m Precision detectors: Very high radiation doses £3M project

T. Bowcock11 Vertex Detector

T. Bowcock12 Radiation Environment cm MeV equivalent neutrons/cm station 6 Dose after 1yr Including effects of walls, vessel High doses at tips –(1/r 2 )

T. Bowcock micron thin n on n detectors with double metal layer (multiple scattering, radiation) r phi z geometry (reflects forward symmetry of the events, optimizes resolution / channel numbers, ease L1 trigger) Baseline Solution r-measuring detector -measuring detector 5 ° stereo tilt resolves ambiguities

T. Bowcock14 Detectors fabricated on 100mm wafer -measuring detectors r-measuring detectors inner radius 10mm readout tracks spaced 50 m UK prototypes

T. Bowcock15 Testbeam

T. Bowcock16 Resolution

T. Bowcock17 Noise S/N with VA2 (slow) electronics Noise –readout line length –strip length

T. Bowcock18 Module Design W/mm Temperature at Tip (°C) Thermal Model: hold cooling at -10 ° C Thermal Runaway LHCb thick detectors Single Sided r and module LHCbUK

T. Bowcock19 Irradiation 4 Detectors Irradiated 11/98 –Heidelberg 20MeV p Lab test Awaiting test beam –stored at -25C

T. Bowcock20 First Test with a Fast Readout Chip (SCTA 128) Main goal: Noise Study Over Spill : first output from one SCTA chip Now: 4 SCTA/hybrid uniform pedestals Noise: 600 ENC : Next testbeam

T. Bowcock21 Summary 1998 Prototype in test beam LHCb like events produced with a target Alignment issues –design modifications Noise Studies Resolution

T. Bowcock22 Physics Performance B s decays B-> Level 1 Trigger z positions+radii #planes tilt angle material effects pitch vs. r break positions stereo angle Use LINUX farm at Liverpool + VX fast simulation Optimization

T. Bowcock23 Some ideas for improvement need to be investigated: smaller pitches -> p on n technology improve resolution, (price ) vary pitch as function of radius optimize occupancy / number of channels / resolution move closer to beam axis reduce outer radius to fit on one wafer reduces number of individual detector modules, ease alignment Improvements?

T. Bowcock24 Simulation Radiation damage Signal –ISE(3D)/Kurata –full 3D diode Thermal analysis

T. Bowcock25 New p-strip design reduced inner radius: 8 mm reduced outer radius: 40 mm requires a few extra stations 182 o modules with 45.5 o sectors (r-detector) inner strip pitch 25 (26) micron, strip pitch increases with r outer strip pitch 99 (131) micron r-detector 2048 strips phi-detector 2048 strips Try different thickness 300, 200 and 140 micron 40.0mm 21.2mm17.9mm 8mm

T. Bowcock Tests of irradiated n-strips in Lab Tests of irradiated detectors (with SCT128A) in test beam

T. Bowcock Irradiation

T. Bowcock28 Irradiated Detector Irradiated (200V)unirradiated (V. Prelim) Irradiation at 3*10 14

T. Bowcock29 Module Precision Mount to platform designed Hybrid Design Lpool +IDE

T. Bowcock30 Mechanics Can adjust to <10microns in space.

T. Bowcock31 Thermal Model Heat Conduction Away from module –separate cooling and mechanical path –no cooling pipes?

T. Bowcock32 Biases?

T. Bowcock33 VD Milestones Technology Choice 9/00 Technical Design Report 01/01?

T. Bowcock34 Current Work SCTa electronics Cosmic Ray & Laser setups Evaluation of Irradiated Detectors –comparison with testbeam

T. Bowcock35 Computing In operation 1PByte stored/year –LCB has set up MONARC Short term –data sets of about 10 8 events optimize detector design background suppression Monte-Carlo Array Processor

T. Bowcock36 MAP operation Run for several weeks events –data will reside on disk! Model for use has been developed –commodity disk servers -1TByte each` –8 TBytes at MAP –5 mirror sites with 0.5TBytes each Minimum required for UK LHCb program –RICH and VD design and optimization

T. Bowcock37 MAP+analysis Institutes Liverpool

T. Bowcock38 Summary Responsibility for LHCb Si Extensive programme of R&D Computing for LHCb-UK –solve immediate optimization problems

T. Bowcock39 Need for Monte Carlo At LHCb about 1 interaction /25ns ! –4*10 14 /year –if you want to do physics you need to know the backgrounds generating just the signals doesnt work –need to generate large MC samples O (10 7 ) to O (10 8 ) events.

T. Bowcock40 Summary LHCb recommended for funding by PPESP ! Intense programme of work to TDR until 2001

T. Bowcock41 MAP contd

T. Bowcock42 MAP status Method –Linux –Batch System –Broadcast point to point transfers for broken sockets –complex code –handling failed/dropped packets.

T. Bowcock43 MAP hardware 300 processors –400MHz PII –128 Mbytes memory –3 Gbytes disk –100BaseT ethernet +hubs –commercial units BUT custom boxes for packing and cooling

T. Bowcock44 MAP use Prepare a job Submit to Batch Queue –at the moment suppress o/p Histograms/Ntuples transmitted back at end of job Random Numbers handled automatically

T. Bowcock45 MAP Performance –About 120s/event GEANT + reconstruction Produce about 200,000 events/day Results –move into production

T. Bowcock46 MAP capabilites Can be used in throwaway mode –just keep Ntuples MAP possesses 1Tbyte internal storage –3 Gbytes/machine –events stored locally (1million events) –repeatedly analyse QUICKLY

T. Bowcock47 MAP+COMPASS

T. Bowcock48 COMPASS Meant to give large storage capability for use of all UK institutes –RICH/VELO studies –PHYSICS DELL prototype in place –1TByte + High End Server (600MHz) transfer rates reliability

T. Bowcock49 COMPASS

T. Bowcock50 COMPASS Purpose –Will show this in place and working with MAP –Model for LHC analysis store events on disks (cheap!) move JOB to the DATA NO HSM

T. Bowcock51 BACKUP SLIDES BACKUP slides

T. Bowcock52 Technology Options for LHCb Vertex Detector procon p strip Single sided processing Rapidly falling efficiency Reduced cost (30%)and ease of handling below partial depletion Minimum pitch 12 m High field region on opposite surface to readout Thin detectors advantageous forNeeds to be thinner for given multiple scatteringoperating voltage.(Lower signal) Handling(cost) of thin detectors. n strip High efficiency at partial depletion givesLithographic processing of back lower operating voltage and lower power(Cost and handling) High field region (after irradiation) at Minimum pitch 40 m. readout strips. Operating partially depleted at tip still allows full depletion (high CCE) elsewhere. both MaterialDifficult to handle Charge CorrelationOffset voltages on one side of detector for electronics. Thermal contact - sensitive face? Prototype 1998

T. Bowcock53 RF shield primary -> secondary Vacuum micron / detector station Best case: 100 micron once Worst case: micron/detector station for low angle tracks (but high p)

T. Bowcock54 Noise Study

T. Bowcock55 Noise Study

T. Bowcock56 pictures of rf shield

T. Bowcock57 Expected Resolution LHCb TRAC 6 micron for theta = 0 o LHCb TRAC 6 micron for theta = 0 o