PWG2 ANALYSIS

1. PWG2 ANALYSIS Panos Christakoglou on behalf of Adam Kisiel

2. Analysis model The analysis has to move to the “production” model: Centralized production AliESD AliESD Filter(s)‏ Analysis train Analysis code AliAOD Histograms Analysis code Histograms

3. Changes to the PWG2 code The move to the “production train”->”analysis train” mode requires conceptual changes in the analysis code The track selection on ESD-only information must be done at the “Filter” level in the production train. Each analysis must provide its own filter. Merging of similar filters is strongly advocated where appropriate The analysis code must be made “AOD aware” - should recognize whether it is running with ESD or AOD input and react accordingly “AOD aware” code must be tested locally, on the GRID, and at CAF (with help from the Analysis Framework team)‏

4. AOD production – PWG2 specific There are PWG2 specific issues connected to the AOD production The AliAODV0 class Creation of the class itself (selection of relevant data to keep)‏ Adapting the Analysis Framework to work with V0's in addition to tracks Creating a specialized V0 filter and selection criteria Additional information for each track e.g. AliFemto requires additional information per track (tpc cluster bitmaps, tpc entrance/exit points)‏ Post-production AOD update Update AOD event-level information with Reaction Plane

5. “AOD-aware” code The analysis code must be made “AOD-aware” The proper AliAnalysisTask-derived class, which knows how to deal with AliAOD input must be provided for each analysis (see AliAnalysisTaskProton for an example) The analysis code must provide a mode in which track selection and analysis procedures are separated. First is moved to the “filter” stage, the second remains in the analysis train Working examples are provided: (anti)proton spectra-ratio-asymmetry advanced analysis with specialized AOD – AliFemto

6. Spectra AliAnalysisTaskProtons – has been fully included and tested in the Analysis Train. Used as an example for all other PWG2 subgroups Reads both ESD and AOD input tested on local analysis, GRID and CAF

7. V0 reconstruction An ESD-to-AOD filter criteria and mechanics is being developed. Needs integration with the efficiency calculation How are the particle filter criteria stored? Code needs to access primary vertices information AliAnalysisTaskESDStrange in CVS Needs to be moved to AOD input, but code is already written in an AOD-aware way – should be straightforward

8. Event-by-Event • Not great activity yet • Only the BF code in SVN • ESD driven analysis • Needs to be revised and changed to make it AOD aware • For the rest of the observables we have tasks implemented but not in SVN • A summer student will help building the tools • By the end of this summer we hope to have the majority of the tools included in the analysis train.

9. Femtoscopy AliAnalysisTaskFemto (in SVN)‏ Supports both the ESD and AOD input through EventHandlers Supports reading MC information via MCEventHandler Tested on local analysis and on the GRID Analysis code (in SVN)‏ Supports ESD and AOD input from the Task Separated track selection into filters (no special requirements)‏ Fixed .par file generation for PWG2femtoscopy and PWG2femtoscopyUser

10. Flow Two analysis tasks in SVN AliAnalysisTaskRLLYZ AliAnalysisTaskRLLYZNewMethod (requires two passes)‏ New task is developed which will provide the estimate of the reaction plane angle and its accurace Will require an update of the AOD Will be an example of the analysis train car, whose input will be needed for cars following in the train (all the reaction-plane aware analysis, e.g. femtoscopy)

11. Resonances • AnalysisTask performing the resonance analysis from ESD/AOD to histos • Merging AliRsnReader and AliRsnAnalysis • Required: • generalization of AliRsnAnalysis class • class: AliRsnManager (work in progress…)‏ • a strategy for event mixing in this case • actually, a very good idea thanks to the discussion with Adam Kisiel about strategy used for Femtoscopy analysis • probably can be implemented as an AliAnalysisTaskSE, with a small-size FIFO collection of processed events to be used for event mixing (when required)  AliRsnEventQueue

12. Resonances cont. • Package is compliant with Analysis standards • Removed dependence on Simulation objects, and all dependence on MC is left to AliMCEventHandlers • Work-flow objects inherited from AliAnalysisTaskSE • able to convert both ESD and AOD events into the internal format • tested and working into AliEn • Defined and tested the Makefile specifications for production of PWG2resonances.par archive • already tested, works perfectly in AliEn and locally in a ROOT (not AliRoot) work session. • In progress the realization of a complete AnalysisTask for the entire operation. • Everything in SVN asap

13. Summary

14. Extra slides

15. Outline The purpose of the exercise Migration from ESD to AOD analysis Writing, testing and debugging the code for the Analysis Train Working examples Proton analysis and reading the AOD Producing analysis specific AOD's Request for the PWG2 software Topics for discussion

16. Resonance code • Internal track format: AliRsnDaughter • inherits from AliVParticle • required for correction framework • MC info: AliRsnParticle • simple class with integer data members • separate object which by default is not initialized. • removed dependence on RunLoaders & stuff • all information is taken only through AliMCEventHandlers (when available)‏ • Internal track collection: AliRsnEvent • does NOT inherit from AliVEvent, because it is more a collection of tracks than a full detail of an event • projected to be a lightweight object, with large use of TRefArrays • Internal PID object : AliRsnPID • to play with all available PID parameters & cuts on them

17. Resonance code • Actual work-flow: • step 1: read an event and store AliRsnEvents • step 2: read AliRsnEvents and produce invariant mass histograms • same AliRsnEvent sample useful for many analysis types • tuning “standard” analysis methods • Step 1: AliRsnReader • base-class object for reading from ESD or AOD or MC events and produce an AliRsnEvent • Derived from it  AliRsnReaderTask • inherits also from AliAnalysisTaskSE • tested OK locally and in AliEn (jobs running to read PDC07 data through it)‏ • Step 2: AliRsnAnalysis • input: AliRsnEvents  output: histograms

18. AliRsnAnalysis class • “Modular” analysis object • collection of “AliRsnPair” objects, each one devoted to building the invariant mass spectrum of a pair of particle types • allows to study several resonances in a single macro or make an analysis in several Pt bins • each AliRsnPair object can be equipped with single and double particle specific cuts, which can be different from each other.

19. Working AOD example All the classes are in AliRoot SVN. The tutorial is posted http://akisiel.web.cern.ch/akisiel/AnalysisOnAOD.html The tutorial macro contains two procedures: produceAOD() - creates the local AOD from the input ESDs. No PWG2 specific filtering is applied runPWG2() - contains an example of the creation of the AOD input chain (from local file) and an example analysis code This tutorial should be the testbed for creation of the “AOD aware” analysis classes for other subgroups of PWG2

20. Creating Your own AOD AOD has been designed to be extendable. Femtoscopy requires additional per-track quality information. We need to extend the AOD in a following way: TRef AliAOD - Event info - Track list - PWG2 info AliAOD - Event info - Track list TClonesArray - track1 - track2 - track3 ... TClonesArray - pwg2track1 - pwg2track2 - pwg2track3 ... TClonesArray - track1 - track2 - track3 ...

21. Creating PWG2 AOD tutorial New PWG2 library is created: PWG2AOD, containing: AliPWG2AODTrack class – with additional per-track information and a TRef to the original AliAODTrack AliAnalysisTaskPWG2ESDfilter – analysis task creating the PWG2 specific AOD runPWG2AODCreation.C example macro A tutorial is available on creating the PWG2 specific AOD with additional per-track information: http://akisiel.web.cern.ch/akisiel/CreatingPWG2AOD.html The PWG2 AOD information is meant to be extended in order to meet the needs of all subgroups

22. Existing PWG2 tasks for the train SPECTRA: AliAnalysisTaskProton (AOD aware)‏ AliAnalysisTaskESDStrange (move to AOD started)‏ FLOW AliAnalysisTaskRLLYZ AliAnalysisTaskRLLYZNewMethod (requires two passes)‏ FEMTOSCOPY AliAnalysisTaskFemto (AOD aware) EBYE RESONANCES

23. Requests for PWG2 software Provide task Filter criteria for the AOD creation Merge Filter criteria when appropriate Provide a functionality of a V0 filter Identify the need and requirements for specialized AOD additional per-event information additional per-track information new AOD information (V0, kinks, etc.)‏ update the existing AOD using analysis results Modify the code to be AOD-aware Identify and separete dependencies on ESD-only information Recognize and differentiate between AOD and ESD input

24. Topics to discuss Which PWG2 subgroups plan to be in the Analysis Train and which Tasks should be used Need to thoroughly test resource-intensive analysis tasks (event mixing): femto and resonances Need to invent a course of action for analysis needing to update the existing AOD (two-pass reaction plane analysis)‏ Do we need PWG2 specific AOD? Other option is a centralized PWG2 request to extend the standard AOD. Centralized track filters for PWG2? - common quality cuts on tracks and events