Commissioning dei muoni D.Orestano Atlas Italia 2/2/2010

Muon analysis readiness walkthrough 23/11/2009: Covering: trigger, calibrations and alignment, DQA, data preparation, muon combined activities, first physics Reviewers: –Nick Ellis (chair) –Karl Jakobs –Ludovico Pontecorvo –David Rousseau –Paul Tipton –Michael Wilson

Recommendations General The MCP group needs to be strengthened with a significant injection of new effort. The relationship between the MRATF activity and the MCP group needs to be addressed by the coordinators from the Muon System and MCP communities, in consultation with the management; at least the aspects of the activity that relate to muon combined performance should come under the responsibility of the MCP group. Physics groups should be more involved in the understanding of muon performance with early data; people from the physics community should contribute to commissioning work with early data within the MCP group. The study of the inclusive muon spectrum needs to be addressed with high priority with a view to an early ATLAS result that can be presented to the outside world. The forum for discussing and coordinating the inclusive muon studies needs to be identified; it is recommended to do this within the context of the MCP group. [The RC is pleased to note that, by the time of writing this Report, a conclusion has been reached on this issue.] Suitable offline muon-selection criteria against which the trigger can be optimized need to be defined. Muon-related trigger and data-preparation activities should be discussed in MCP meetings.

Trigger It is extremely urgent to develop and implement a detailed plan for the analysis of the trigger in the 900 GeV data; this is a natural milestone in preparation for the 7 TeV running. More effort is needed for muon trigger studies, and it is critical that new effort be integrated very rapidly and coordinated effectively. Communications between the MCP group and the muon trigger group should be improved; the work and meetings should be planned in close collaboration between the respective convenors. Public tools should be made available for muon trigger analysis. Calibration and alignment There should be a plan detailing all special runs required for calibration and alignment studies. Calibration and alignment work should start as soon as possible with collision data recorded at 900 GeV. Data quality More effort needs to be found for the muon data-quality monitoring shifts. Guidance is needed on the relationship between the detector and the Combined Performance DQ flags. It is recommended that the TOB look at this issue that has also been identified in other Walkthroughs. There should be more input from the physics groups to the definition of the DQ flags.

Data preparation It is recommended to converge on the content of the dESDs with a view to increasing their use. The use of common data formats between the MCP and the muon trigger community is encouraged where appropriate. There is a general need for more attention to the simulation, including rapid feedback based on experience with real data. The community is encouraged to complete the preparation and validation of the full field maps (symmetric and also asymmetric versions) as soon as possible. A group space manager should be identified. Muon combined performance A more detailed MCP work plan, task list and schedule should be produced quickly; it is recommended to break the work down into tasks that can be taken on by individuals; priorities should be established and effort should be assigned. [The RC is pleased to note that the MCP conveners are already working in this direction, as presented in the Walkthrough meeting.] The MCP work plan should include, prominently, the use of the inner detector and the calorimeters in understanding the muon performance (see text in General Remarks and MCP sections). All the MCP code used in performance studies should be put into the official SVN code repository.

Data analysis There is a need for studies of the inclusive muon spectrum involving all relevant communities. This should include involvement from the relevant physics working groups (SMP, B-physics, J/psi, etc), although it is recommended that the activity should come under the responsibility of the MCP group. The analysis needs to plan for data reprocessing to ensure that elements are delivered on time.

Follow-up Meeting on inclusive muon studies started in December. Now meeting every 2 weeks (Tuesday after Atlas Weekly). Pursue both understanding of early data and physics measurement. Working meetings on early data analysis alternating with MAFT on Wednesdays (from February). MAFT will cover MS only, MCP will cover combined aspects. Frequent exchanges with muon trigger signatures group for both activities First definition of DQA MCP virtual flags: posal#Muons posal#Muons need input from physics groups!

Results on cosmics Cosmics analysis still ongoing: still the main source of muons for high statistics studies Results mainly on MS standalone from MAFT group. Very good MS resolution achieved with the latest alignment and recent cosmics (4% up to 30 GeV) Combined studies include –Energy loss and isolation –MS-ID comparison –MS-ID relative alignment

Beam splash Very important for relative timing of the different detector elements In particular MDT t0s from beam spash events (+ global t0 offset obtained from collision candidates) will be used in next reprocessing

Results on 900GeV collisions Very low statistics collected for muon studies Muon distributions for toroid off data approved in December Working towards the approval of toroid on distribution. Results from both collections in agreement with MC, see

Attività dei gruppi italiani

Level-1 Muon Barrel A new tool to validate road from data Proven fundamental to find problem During Christmas hardware work to recover them – sensible validation can be started with ~2000 muons/RoI (L1_MU10). Mu0 Mu6 Programmed Any combination it should be it was it is now! D.Della Volpe

L1 Muon Barrel timing - MdV What about efficiency? We cannot quote the efficiency. Too few muons Toroid Muon tracks RPC Triggers eff. OFF8788 % ON % Trigger efficiency calculation with few thousands of good muons, averaged in phi and in few eta bins, for first inclusive studies

L1 Muon Barrel timing - MdV Maps of Delays trigger tower sector logic trigger tower high pt low pt ± 3 BC as expected 1 BC late than L1A coarse alignment ( ~ BC ) need 100 muon per tower fine alignment (~ 5 ns) needs 1000 muons per tower

J/PSI   Tag&Probe in InsituMuonPerformanece G. Chiodini - INFN Lecce Spagnolo & N. Orlando - INFN Lecce and Università del Salento Basic motivations: – J/PSI  T&P integrated in insituMuonPerformance in order to profit of the high quality and physics analysis oriented package developed by: C. Bini, S. Borroni and S. Rosati – HANDS-ON EARLY DATA AND MUON PERFOMANCE – Interplay with Z  T&P in the overlap region around 20 GeV. Important cross-check of single muon efficiency – Relevant for B-Physics studies – Detailed studies of trigger turn-on curve in low pt difficult regime in an analysis oriented data driven efficiency measurements.

J/PSI  Tag&Probe on collisions 2009 To deal with background is essential in order to boost statistics and use earliest data available. Tag (Combined Muon) and probe (Inner Detector Muon) invariant mass JPSI T&P out of the box removing all cuts. No signal peak above background. “The best way to debug your code and take it seriously is to run on real data” Work in progress

Muon High Level Trigger Validazione e commissioning usano ESD e Ntupla di Trigger Statistica di muoni candidati da collisioni molto limitata, Trigger Reprocessing ancora in corso Reprocessing corregge via sw le RoI, per il problema firmware MuCTPi (risolto al pit da Gennaio) L1 MU6, L2 mu6_Msonly, EF mu6_Msonly, L1_MBTS_1_1_COL Trigger Reprocessing Pilot Run ( Toroid on, Solenoid on, stream MuonswBeam) ntuple analysis:

Pilot Run , MuonswBeam, Analisi della ntupla. Il flusso per le catene definite nel menu e’ quello atteso: Efficienza di MuFast rispetto all’Event Filter (step dell’estrapolazione standalone, EFSA) Catene MSonly_passL2 Black = muFast ok Blue = L2 mu6 passed (Black->Blue: taglio sul p T ) taglio “di puntamento” su EF SA |d0| < 500 mm _passL2MS (MuFast in Pass Through,MuComb,Combinazione con ID all’EF) -> MuComb Commissioning _L2MSonly_passL2 (MuFast in Pass Through, Combinazione con ID all’EF) -> EF Commissioning Mu4 Mu4_MSonly Mu4_ L2MSonly_ passL2 Mu4_passL2MS

Pilot Run : confronto Trigger vs Offline MuidSA (estrapolazione SA) richiedendo il trigger MBTS_1_1_Col, MuonswBeam, analisi della ntupla MuidSA

MuidCB p T < 4, passa solo se MuFast e’ in Pass Through (catena L2_mu4_passL2MS) Pilot Run : confronto Trigger vs Offline MuidCB (combinazione con l’ID) richiedendo il trigger MBTS_1_1_Col, MuonswBeam, analisi della ntupla

Pilot Run : Event Filter vs Offline Moore, data set DESD_COLLCAND Catena EF_mu4_MSonly 16 eventi passano la selezione COLLCAND, di cui 6 passano il L2 e 4 passano l’EF dei muoni La correlazione EFMS (solo spettrometro) – Moore e’ ottima per 3 dei 4 muoni EFMS-Moore: correlazioni in eta e phi

EFMS-Moore: numero di hits per traccia Pilot Run : Event Filter vs Offline Moore, data set DESD_COLLCAND

Conclusioni Il walkthrough ha permesso di far partire la nuova struttura organizzativa per gli studi di performance degli algoritmi combinati e lo studio dello spettro inclusivo Il commissioning degli oggetti muonici risente della bassa statistica raccolta nelle prime collisioni Queste sono comunque state usate per identificare dei candidati offline, per studiare le correlazioni tra offline e online e predisporre gli strumenti per il commissioning delle analisi e del trigger Le attività italiane sono numerose e spesso abbracciano più aspetti, contribuendo significativamente alla connessione tra il commissioning del rivelatore e del trigger, quello del software, ed i gruppi di fisica.

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L1 Muon Barrel timing - MdV Road Map LVL1 for final commissioning Timing – The method shown can be easily used with collision – coarse alignment ( ~ BC ) need 100 muon per tower – fine alignment (~ 5 ns) needs 1000 muons per tower Validation of the pT threshold ( trigger roads ) – Defined to maximize trigger efficiency using single muon monte carlo – Depends on modeling of magnetic-field, geometry, materials – Depends on statistics, detector areas with less acceptance have larger coincidence roads – Trigger roads must be validated with data using reconstructed muon – Use MU0 as the maximum acceptance threshold – Use calibration stream as well: no rejection by L2, no prescales – Trigger roads: sensible validation can be started with ~2000 muons/RoI (L1_MU10). Note: need to consider separately for mu+/mu-

L1 Muon Barrel timing - MdV One week at – O(100k) muons with low pT from heavy quark decays – A few 10 k muons from W, few 100 from Z – Important sample of inclusive muons (tag and probe is very statistics limited) With 10 pb -1 large statistics will allow: – Precise determination of parameters: L1 trigger roads – Precise determination of performance: pT resolution, trigger efficiency with tag and probe Level1 muon trigger at 7 TeV

P µ = 3.25 GeV P T µ = 3.02 GeV RPC BM Low pt Confirm RPC BM Pivot IP

J/PSI  Tag&Probe features Specific features: JPSISelectionTool from J/PSI B-Physics analysis code of Samira et al. Two trigger tools for trigger selection and matching fully driven by joboption: – TriggerAnalysisTool – JPSITrigEffTool make possible cross-studies inside the same piece of code. Efficiency extraction with background (under development) Properties inherit from InsituMuonPerformance: Inner detector probe and muon probe (absolute and relative trigger efficiencies) Tag, Probe and Tag&Probe selection cuts driven by joboptions Detailed CBNT ntuple, Histograms and summary efficiency cuts in ascii file in output 3D (pt,eta,phi) APEfficiency matrix generation for each trigger level, hypoalgs and muon track types in COOLDB for benchmark physics analysis.