1

Developments of the PWG3 muon analysis code

Alice Offline Week, July 10th 2008

Analysis Train for the standard AOD generation from the ESD

Preparation of AOD replication for muon tagged events

Analysis tasks for the determination of the efficiency of the

• Tracking chambers• Trigger chambers

Other developments in the PWG3 muon analysis code:

Analysis task to fill the standard AOD with the muon information

2

From the ESD to the standard AODUp to now the AOD generation from ESD was done using only one analysis task

ANALYSIS/AliAnalysisTaskESDfilter.cxxfor all the tracks, including muons

Now there is a new analysis task which takes care of filling in the AOD the muon tracks to allow a better modularity

PWG3/muon/AliAnalysisTaskESDMuonFilter.cxx

AliAnalysisTaskESDfilter

AliAnalysisTaskESDMuonFilter

ESD

AOD

AliAnalysisTaskESDfilter

ESD

AOD

3

Analysis Train

The AOD creation from the ESD will now be done calling the two analysis tasks:

AliAnalysisTaskESDMuonFilter *esdmuonfilter = new AliAnalysisTaskESDMuonFilter("ESDs");

1) ANALYSIS/AliAnalysisTaskESDfilter.cxx which writes in the AOD:• the header of the event• all the tracks apart from muons• other infos

2) PWG3/muon/AliAnalysisTaskESDMuonFilter.cxx which updates • the tracks branch in the AOD, adding the muons• the header of the event

AliAnalysisTaskESDfilter *esdfilter = new AliAnalysisTaskESDfilter("ESD Filter");

Muon information are copied from

AliESDMuonTrack AliAODTrack

4

New methods in AliAODTrack

Track parameters at DCA have been added to the AliAODTrack:

• Double32_t fMomentumAtDCA[3]; // momentum (px,py,pz) at DCA • Double32_t fPositionAtDCA[2]; // trasverse position (x,y) at DCA

• void SetXYAtDCA(Double_t x, Double_t y); • void SetPxPyPzAtDCA(Double_t pX, Double_t pY, Double_t pZ);• Double_t XAtDCA();• Double_t YAtDCA();• Double_t ZAtDCA();• Bool_t XYZAtDCA(Double_t x[3]);• Double_t DCA();• Double_t PxAtDCA();• Double_t PyAtDCA();• Double_t PzAtDCA();• Double_t PAtDCA();• Bool_t PxPyPzAtDCA(Double_t p[3]);

Philippe Pillot

Corrected methods dealing with fITSMuonClusterMap in AliAODTrack with the method AliAODTrack::IsMuonTrack() it is possible to correctly select muons in the muon arm

In AliAnalysisTaskESDMuonFilter.cxx the AODTracks are now filled with these new infos

New methods added to the AliAODTrack

5

Test of the analysis train

The analysis train has been tested

• Locally• CAF• GRID by Mihaela Gheata

The macro has been tested on the CAF using some files from the PDC08/LHC08t minimum bias pp@14TeV PDC07/LHC07g dimuons pp@14TeV

The macro to run the analysis train on the CAF is

PWG3/muon/AnalysisTrainMuonCAF.C

6

AliESDMuonTrackCutsNew class implemented to provide the possibility to apply some selection cuts on the muon tracks before filling the AOD: PWG3/muon/AliESDMuonTrackCuts (based on a similar class already existing for the AliESDtrack: AliESDtrackCuts)

AliAnalysisTaskESDfilter

AliAnalysisTaskESDMuonFilter

ESD

AOD

Cuts on muon tracks

AliESDMuonTrackCuts* esdMuonTrackCut = new AliESDMuonTrackCuts("AliESDMuonTrackCuts", "");

esdMuonTrackCut->SetPtRange(0.,0.5); // examples of kinematic cuts that can be appliedesdMuonTrackCut->SetHistogramsOn(kTRUE); // methods to draw control histosesdMuonTrackCut->DefineHistograms();esdMuonTrackCut->DrawHistograms();

AliAnalysisFilter* trackMuonFilter = new AliAnalysisFilter("trackMuonFilter");trackMuonFilter->AddCuts(esdMuonTrackCuts);

AliAnalysisTaskESDMuonFilter *esdmuonfilter = new AliAnalysisTaskESDMuonFilter("Muon”);esdmuonfilter->SetTrackFilter(trackMuonFilter);

7

AliESDMuonTrackCuts (2)

For the moment only kinematic cuts are implemented

Number of tracks not surviving the pT cut

Number of tracks not surviving the p cut

Number of rejected tracks

Number of muon tracks

8

Muon-AOD replication

ESD

Standard AOD

MUON AOD replication

• This step is ready and tested

• AOD containing only events where muons in the dimuon spectrometer are present.

Need to select events containing only muons

9

Selection of muon events

Several possibilities to select events containing only muons:

2) Read the AliAODHeader and read the event only if it contains muons but in the AliAODHeader the number of muons is not stored.

3) Use the AliAODTags

Applying cuts on the Event level

1) Loop on the events and select only those containing muons time consuming

AliTagAnalysis *TagAna = new AliTagAnalysis("AOD"); AliEventTagCuts *evCuts = new AliEventTagCuts();evCuts->SetNMuonRange(1,1); TChain* chain1 = 0x0;TagAna->ChainLocalTags("/n60raid3/alice/roberta/ESDMuon/TagAODTest");chain1 = TagAna->QueryTags(runCuts,lhcCuts,detCuts,evCuts);

10

AliAODTags

The AliAODTags can be the approach to follow in order to select events containing muons

Once we have tagged events containing at least one muon, the next step is the creation of a Muon-AOD replica containing:

• the header of the event• the full event which contains the muon

Replica of theevents Header

AOD

Muon AOD

AliAODTags

to filter muonsReplica of

track branchReplica of

other branches

11

Muon-AOD replica

The idea is to create a replica of the standard AOD containing events where at least one muon is present

• Method to automatically copy (from standard AOD to user-AOD) the header of the interesting events is already implemented AliAODHandler::SetNeedsHeaderReplication()

• Methods to automatically copy other branches from the standard AOD to the user AOD not yet available

Generalizing the code for AOD header replication, we have implemented, as a test, the replica of the TRACK branch for the interesting events

AliAODHandler::NeedsTracksBranchReplication()

12

Muon-AOD (2)

The replica is done in AliAnalysisTaskSE

AliAnalysisTaskSE::CreateOutputObject()If(handler->NeedsTracksBranchReplication(){ fAODTracks = new TClonesArray("AliAODTrack",500); handler->AddBranch("TClonesArray", &fAODTracks);}

AliAnalysisTaskSE::Exec()If(handler->NeedsTracksBranchReplication(){ AliAODInputHandler* aodH =dynamic_cast<AliAODInputHandler*>(fInputHandler); for(int i=0;i<InputEvent()->GetNumberOfTracks();i++){ AliAODTrack *track = dynamic_cast<AliAODTrack*>(InputEvent()->GetTrack(i)); new((*fAODTracks)[i]) AliAODTrack(*track);} }

Is this a suitable way to proceed in order to produce a replica of the AOD?

Code not yet committed

Should we foresee other methods to replicate all other useful branches?

13

Creation of Muon-AOD

MUON-AOD replication could be done in the official analysis train

small data size of the MUON AOD replica

Several AODs files could be merged

~106 muon tracks in a 3 hours run in p-p @ 14TeV at nominal luminosity

Our proposal:

In p-p @ 14TeV we expect 1 muon track out of ~200 min. bias collisions:

14

Method to add new branches (as the dimuon branch) to the standard AOD exists: AliAnalysisTaskSE:AddAODBranch()

Classes to compute dimuon information already existing

PWG3/MUON/AliAODDimuon.cxx

Adding dimuon information

Once the MUON-AOD replica will be available, it will be possible, maybe as a further step, to add a dimuon branch, to include dimuon information

Muon AOD Add dimuon branch

Dimuon AOD

Histos

Macros for analysis

15

Link between AODs and MCJulien Faivre

Requirement from the last PWG3 meeting:

Important to keep track of the link between the MC information and the AOD.What happens if the AOD granularity is different from the ESDs one?

16

Intrinsic efficiency of the tracking chambers

The intrinsic efficiency of the tracking chambers represents the “quality” of the wires chambers of the dimuon arm. This efficiency is given by:

This efficiency must be calculated with the real data. This is the goal of the Analysis task:

1. intrinsic efficiency as a function of the position in each detection element of each chamber. 2. total intrinsic efficiency of each chamber (one plane of detection elements)3. number of tracks used for the efficiency calculation (for errors calculation).

Number of muons detected by the chamber

Number of muons which have passed through the chamberεintrinsic=

Those classes depend on MUON packages our proposal is to create a new library PWG3muonMUON for the PWG3 classes that depend on MUON packages

AliAnalysisTaskMuonTrackingEff & AliCheckMuonDetEltResponse

Nicolas LeBris

17

Intrinsic efficiency of the tracking chambers (2)

AnalysisTaskMuonTrackingEff.C

RunAnalysisTaskMuonTrackingEff.C

AliAnalysisTaskMuonTrackingEff.cxxAliCheckMuonDetEltResponse.cxx

Input files

Output histograms

Efficiency as function of the position for each detection

element

Total efficiency of each chamber (10 chambers in

the spectrometer )

geometry.root

AliESDs.root

( local or batch mode)

AliMuonTrackingChamberEffHisto.root

Output file

Results from a simulation of 10000 J/Ψ (20000 muon tracks)

18

Intrinsic efficiency of the trigger chambers

The intrinsic efficiency of the trigger chambers is provided for the local boards

Efficiency will be calculated separately for bending and not bending plane

Diego Stocco

Trigger tracks are created when 3 out of 4 chambers are hit both on the bending and in the non-bending plane

Method already tested in the cosmic run

Efficiency will be calculated with the real data.

Number of muons detected by the chamber

Number of muons which have passed through the chamberεintrinsic=

19

Intrinsic efficiency of the trigger chambers (2)

AliAnalysisTaskTrigChEff.cxx

PWG3/muon/AnalysTrigChEff.C

Input files

AliESDs.root

( local or batch mode)

MUON.TriggerEfficiencyMaps.root which contains the ingredients for the eff. calculation

Output

20

Conclusions

Analysis Train (with separated filling of the muon tracks) has been tested locally/CAF/Grid

Production of muon AOD under discussion:

• The use of metadata information could help selecting events containing only muons.

• Need to replicate useful branches from the standard to the Muon AOD code to be completed and committed

Possibility of applying cuts on the muon tracks before filling the standard AOD has been implemented

AnalysisTasks for tracking/trigger chamber efficiency is ready