Whats in the ATLAS data Trigger Decision ATLAS

What’s in the ATLAS data : Trigger Decision ATLAS Offline Software Tutorial CERN, 20 -22 August 2008 Ricardo Gonçalo - RHUL

Trigger Selection Level 1 Region of Interest is found and position in EM calorimeter is passed to Level 2 Event rejection possible at each step EM ROI L 2 calorim. cluster? Electromagnetic clusters Level 2 seeded by Level 1 Fast reconstruction algorithms Reconstruction within Ro. I L 2 tracking track? match? E. F. calorim. E. F. tracking Ev. Filter seeded by Level 2 Offline reconstruction algorithms Refined alignment and calibration track? e/ reconst. e/ OK? ATLAS Software Tutorial 2 Ricardo Gonçalo

n ¨ n EMROI Algorithm execution managed by Steering Based on static trigger configuration L 2 calorim. T. E. Trig. EMCluster Step-wise processing and early rejection Chains stopped as soon as a step fails ¨ Event passes if at least one chain is successful ¨ L 2 calorim. cluster? L 2 tracking n Feature Extraction algorithms (FEX) ¨ Features (i. e. objects) cached to avoid timeconsuming reconstruction T. E. track match? Trig. In. Det. Tracks E. F. calorim. n Navigation links between Trigger. Elements ¨ Navigation to objects possible in chain tree E. F. calorim. T. E. E. F. tracking Calo. Cluster track? n Trigger objects stored in ESD/AOD/DPD Trigger “features” (id tracks, clusters, muon candidates, electron candidates, etc) ¨ Navigation links (Trigger. Elements) ¨ Trigger Configuration (file header) e/ reconst. ¨ ATLAS Software Tutorial 3 e/ reconst. T. E. egamma OK? e OK? Ricardo Gonçalo

Configuration Data Flow All configuration data es or ded t S o r c e de rigg nu T e M s re igu nf Co Preparation Trigger. DB Data taking Online Conditions Database Encoded trigger decision (trigger result from all 3 levels ) Decoded Trigger Menu Trigger Result Reconstruction/ Trigger aware analysis Trigger EDM AOD • Trigger objects for trigger selection studies DPD Trigger Configuration • Trigger names (version), prescales, pass throughs Ricardo Gonçalo ESD access through Trig. Decision. Tool ATLAS Software Tutorial TAG With decreasing amount of detail • passed? , passed through? , prescaled? , last successful step in trigger execution? 4

Trig. Decision. Tool The Trig. Decision. Tool is the analysis interface to the trigger information in Athena It reads the trigger decision object (Trig. Decision) and the trigger configuration Dynamic information (event-by-event) • Configuration information: – What triggers passed/failed – Did they pass because of e. g. passthrough? – Navigate/retrieve trigger objects from each chain Trig. EMCluster T. E. Trig. In. Det. Tracks T. E. Calo. Cluster T. E. egamma T. E. Ricardo Gonçalo – Configured chains – Prescale and passthrough factors – (Trigger) stream tags Class Trig. Decision private: int m_config. Master. Key; Lvl 1 Result m_l 1_result; Data. Link<HLTResult> m_l 2_result; Data. Link<HLTResult> m_ef_result; HLT configuration list of chains and sequences Trig. Decision. Tool • CTP Configuration ATLAS Software Tutorial 5

Persistent Different Transient configuration object stored POOL data Trig. Config. Svc On supports request Contains forinterface by CTPDecision different Tool, expands and cases: and Common touse several online, caches offline, Configuration HLTResult analysis and configuration DBAOD/ESD implementations Navigation information Trig. Decision transient object T/P converter Trig. Decision. Tool user interface Trig. Config. Svc Trig. Decision_p 3 persistent object unpack Trig. Decision. Tool: user interface; unpacks and interprets Trig. Decision through configuration info 27 Mar 07 Ricardo Goncalo - new Trig. Decision Trigger. DB COOL AOD header 6

How-to use Trig. Decision. Tool in Athena 1. 2. Add to your algorithm a Tool. Handle to point to a Trig. Decision. Tool Initialize Tool. Handle in constructor (adviseable to use as public tool) 3. Retrieve tool in initialization 4. Use tool in execute e 15 i isolated p. T>15 Ge. V electron Ricardo Gonçalo private: Tool. Handle<Trig. Decision. Tool> m_trig. Dec; My. Algo: : My. Algo(const std: : string &name, … m_trig. Dec("Trig. Dec: : Trig. Decision. Tool/ Trig. Decision. Tool”) { declare. Property("Trig. Decision. Tool", m_trig. Dec, ”The tool to access Trig. Decision”); Status. Code sc = m_trig. Dec. retrieve(); if ( sc. is. Failure() ) { (*m_log)<< MSG: : ERROR<< “Help!”<< endreq; return sc; } std: : string sig_name(“L 2_e 15 i”); if (m_trig. Dec->is. Configured( sig_name )) { if ( m_trig. Dec->is. Passed( sig_name )) { (*m_log) << MSG: : INFO << ”I’m happy!" << endreq; } } ATLAS Software Tutorial example More complete 7 in Trig. Decision. Tool 14 twiki

Retrieving trigger objects std: : vector<const Trig. Tau. Cluster* > vec_tau. Clust; ec = m_trig. Dec->get. Pass. Features("L 2_"+trig. Item, vec_tau. Clus); if (ec == HLT: : OK) { std: : vector<const Trig. Tau. Cluster* >: : const_iterator CI=vec_tau. Clus. begin(); for ( ; CI != vec_tau. Clust. end() ; ++CI) { (*m_log) << MSG: : INFO << ”Energy in EB sampling 1: "<< (*CI)->energy(Calo. Sampling: : EMB 1) << “ Energy in EB sampling 2: "<<(*CI)->energy(Calo. Sampling: : EMB 2) << " Energy in EB sampling 3: "<<(*CI)->energy(Calo. Sampling: : EMB 3) << endreq; } } else return Status. Code: : FAILURE; Trig. Dec. Checker 06 Aug 07 BNL INFO REGTEST L 1 Ro. I Eta, Phi: 0. 4, -1. 47262 INFO REGTEST Energy in EB sampling 1: 26935 Energy in EB sampling 2: 53473 Energy in EB sampling 3: 824 INFO REGTEST L 2 leading track pt: 55944. 9 Trigger analysis - S George & R Goncalo 8

What else can it do? Well documented in the code and in Doxygen Ricardo Gonçalo ATLAS Software Tutorial 9

Outlook • The trigger information available for analysis is now quite complete • Work currently ongoing (or at least in the pipeline): – Providing/improving access to trigger data outside Athena – Slimming navigation for inclusion in DPDs • Will be included without slimming in 2008 – Cleaning up the Trig. Decision. Tool interface – Providing “navigation” links between offline objects and trigger navigation as a common feature • The first priority: make the trigger run with real data! …And use this experience to find what else we need Ricardo Gonçalo ATLAS Software Tutorial 10

More info General Trigger info: • Trigger User Pages, general entry point for information: https: //twiki. cern. ch/twiki/bin/view/Atlas/Trigger. User. Pages • Trigger Event Data Model (EDM) : https: //twiki. cern. ch/twiki/bin/view/Atlas/Trigger. EDM Trig. Decision. Tool: • Doxygen: http: //atlas-computing. web. cern. ch/atlascomputing/links/latest. Doc. Directory/Trig. Decision/html/class. Trig. Dec_1_1 Trig. Decision. Tool. html • Wiki: – – Release 13: https: //twiki. cern. ch/twiki/bin/view/Atlas/Trig. Decision. Tool 14 Release 14: https: //twiki. cern. ch/twiki/bin/view/Atlas/Trig. Decision. Tool 14 (with examples using Analysis. Skeleton) • Example using Rec. Ex. Common environment: Trig. Decision. Checker http: //atlas-sw. cern. ch/cgi-bin/viewcvsatlas. cgi/offline/Trigger/Trig. Validation/Trig. Val. Algs/Trig. Decision. Checker. h? revision=1. 2&view=markup (test algorithm used for trigger validation) Outside Athena: • ARA: (April ATLAS Overview Week) http: //indico. cern. ch/material. Display. py? contrib. Id=56&session. Id=10&material. Id=slides&conf. Id=22136 • SPy. Root: (not official trigger wiki) https: //twiki. cern. ch/twiki/bin/view/Atlas/SPy. Root. Retrieving. Trigger. Objects When something goes wrong: – Trigger. Help Hypernews forum (hn-atlas-Trigger. Help@cern. ch) Ricardo Gonçalo ATLAS Software Tutorial 11

Backup Ricardo Gonçalo ATLAS Software Tutorial 12

• • – – • Hardware based Calorimeter and muons only Latency 2. 5 s Output rate ~75 k. Hz • Event Builder: ~100 farm nodes(*) Event Filter (EF): ~1600 farm nodes(*) – – – Seeded by level 2 Potential full event access Offline algorithms Average execution time ~4 s(*) Output rate up to ~200 Hz Calorimeter Trigger Ro. I’s 75 k. Hz ROIB T ROD L 2 P ~40 ms L 2 SV L 2 N Event Filter~4 sec EFP EFP Ro. I requests Ro. I data LVL 2 Acc. 2 k. Hz EF Acc. ROD 120 GB/s (Region of Interest) LVL 2 L 1 PB/s 2. 5 s Muon LVL 1 Acc. Trigger CTP H Calo Mu. Tr. Ch. Other detectors Pipelines LVL 1 ROB ROB ROS 3 GB/s Event Builder EB EFN 200 Hz Event Size ~1. 5 MB (*) 8 CPU (four-core dual-socket farm nodes at ~2 GHz ATLAS Software Tutorial DAQ 40 MHz Level 2: ~500 farm nodes(*) – Only detector ”Regions of Interest” (Ro. I) processed - Seeded by level 1 – Fast reconstruction – Average execution time ~40 ms(*) – Output rate up to ~2 k. Hz • Trigger Three trigger levels: Level 1: 13 300 MB/s Ricardo Gonçalo

Super Master HLT Master - Super. Master table contains links to L 1 and HLT master tables - HLTMaster table defines complete HLT configuration - L 1 Master table defines complete L 1 configuration: the L 1 menu and CTP config the supermaster ID (“key”) chooses matching L 1 + HLT trigger menus Configuration Database L 1 Master Aim to configure the trigger from DB also outside point 1 validation on the CAF; trigger Level 1 - trigger HLT simulation; trigger development The advantage is to access the same trigger configuration as was used for data taking easy to achieve reproducibility Trigger. DB to be available at Tier 0/1 (Oracle), and Tier 2 (SQlite) First running version in 14. 2. 10 3

06 Aug 07 BNL Trigger analysis - S George & R Goncalo 15