CLIC WG 6 Issues and Plans Mark Thomson

CLIC WG 6: Issues and Plans Mark Thomson University of Cambridge

This Talk Three Main Topics: § Outstanding Reconstruction Issues § Discussion of plans for overlay § Planning Context: § Need to finish ILD and Si. D reconstruction chains by end of month • a significant delay would be problematic • might require >1 iteration § Still have not fully validated ILD or Si. D reconstruction chains for non-overlayed events • need to complete the checks • need to fix reconstruction configuration § Major issue is overlay • full bunch train overlay will not be possible • need to define our strategy (what approximations are OK) § WG 6 meeting on 26 th January is an important deadline CLIC WG 6, 10/1/2011 Mark Thomson 1

Critical Path CLIC WG 6, 10/1/2011 Mark Thomson 2

Reconstruction: Critical Path 1) Particle Flow Reconstruction ILD PFA § move to new Pandora. PFA version § validate (again) mu, e and photon ID are reasonable [Jacapo? ] • at this stage mostly checking nothing broken • assuming no further development § check track quality requirements well matched to CLIC_ILD_CDR [Mark/John ? ] Si. D PFA § mods to Si. DPandora to interface to new Pandora. PFA version [Norman/Marcel ? ] § check mu, e and photon ID do something reasonable [Jacapo? ] § check track quality requirements [? ] § algorithm tuning [Norman/Marcel/Angela? ] CLIC WG 6, 10/1/2011 Mark Thomson 3

Reconstruction: Critical Path 2) Tracking ILD Tracking § check new Silicon. Tracking. CLIC [Andre/Marco? ] • including optimised steering file § final validation of performance [Andre? ] • essentially check nothing broken Si. D Tracking § reconstruction time improvements [SLAC? ] § final validation of performance [Christian? ] • check nothing broken § understand limitations with overlay [? ] CLIC WG 6, 10/1/2011 Mark Thomson 4

Reconstruction Critical Path 3) Flavour-tagging ILD/Si. D § define code to be used for production 4) Overlay/Timing ILD/Si. D § decide on timing reasonable parameters (see next section for ILD) § prepare overlay steering § timing information in PFO selection 5) Technical ILD/Si. D § manage software releases for CDR processing/steering § prepare reconstruction steering files § decide on DST format(s) CLIC WG 6, 10/1/2011 Mark Thomson 5

Overlay CLIC WG 6, 10/1/2011 Mark Thomson 6

Overlay: Calo Issues E/Ge. V Requirements here determined by “slow” Tungsten HCAL barrel response § Need relatively long integration times Tungsten Need to integrate over 25 -50 ns § sets minimum number of bunches to be overlayed at level of 50 -100 § e. g. suppose we only overlayed 50 bunch-crossings and integrated over 25 ns, would neglect the “slow” background hits from earlier BXs § does this matter ? CLIC WG 6, 10/1/2011 Mark Thomson 7

Overlay: Calo cont. Can see the slow tail in full bunch-train overlay § effect of slow component not dominant § probably not a major issue CLIC WG 6, 10/1/2011 Mark Thomson 8

ILD Calo Time Stamping Proposed Calorimeter time stamping Single hit resolution – 1 ns § are modifications needed for overlay processor (negative times) ? Multi-hit separation: 20 ns § implemented crude peak finding in ILDCalo. Digi § may still be some occupancy issues in forward HCAL Full bunch train r/mm CLIC WG 6, 10/1/2011 r/mm Mark Thomson 9

Overlay: TPC Issues For TPC, ideally would superimpose full bunch-train Some progress with ILD reconstruction (slicing in z) but full TPC overlay for mass reconstruction almost certainly not feasible Will need standalone studies to demonstrate track reconstruction efficiency Propose limited TPC overlay for mass reconstruction, compatible with requirements from calorimeter, 50 -100 bunch-crossings CLIC WG 6, 10/1/2011 Mark Thomson 10

TPC Time-stamping Displaced vertices probably rule out stand-alone TPC track time-stamping § anyone disagree with this statement ? Accept only TPC tracks with either: § at least n VTX hits § at least 1 associated SIT hit § at least m associated FTD hits § an associated, in time cluster • cluster time calculated as energy weighted mean hit time • cuts on cluster time < 5 ns look feasible With these requirements would expect to reject all TPC tracks from BXs > 10 ns from physics event Hence only approximation in limiting TPC overlay to 50 -100 BXs is that track inefficiencies may not be accounted for § standalone study with full bunch-train to check this CLIC WG 6, 10/1/2011 Mark Thomson 11

ILD Time-stamping Strawman proposal for discussion: Routinely overlay 110 BXs § driven by W HCAL timing § technical issues, e. g. GRID ? Physics event at BX number 10 § allow for main calorimeter contributions from previous BXs Calorimeter time resolution of 1 ns with 20 ns multi-hit separation Silicon detectors integrate over 10 ns § assumes starting time of integration is “physics hit” – occupancy ? TPC track reconstruction for full 110 BX § tracks selected based on timing in other detectors PFO Selection (needs study, just first estimate) § photons – require cluster time < 1 ns § neutral hadrons – require cluster time < 5 ns § tracks with cluster – require in time cluster (<5 ns) • need to account for helical track time to reach calorimeter § tracks with no associated cluster – reject ? If agreed, will try and implement this by end of week CLIC WG 6, 10/1/2011 Mark Thomson 12

Planning CLIC WG 6, 10/1/2011 Mark Thomson 13

Schedule Aim to have CLIC_ILD and CLIC_SID reconstruction paths by end January § WG 6 meeting on 26 th January would like presentations on all remaining cross checks § following days used to tag software/run test jobs § people will need to look critically at the output (more validation) § then commence physics reconstruction ~ 8 th February § finalised flavour tagging tools ~ mid-February § physics DSTs ready end February In parallel § Standalone studies: • timing in tracking • timing in PFA • flavour tagging IWLC 2010, Geneva Mark Thomson 14