Cosmic Ray

Run III Cosmic RayAliEn Catalogue LHC08b

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Cosmic ray Run III

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AliEn RepositoryDescription : RUN III cosmicsProduction : PDC 08/LHC08bRun Range: 34784-42384

Detectors: HMPID PMD SDD SPD SSD TPC TRD TRIGGER

Number of Events Analyzed: 505119

Not trigger information in the ESD file, For the moment, I manually get this information from the logbook.

See one Example:https://alice-logbook.cern.ch/logbook/date_online.php?p_cont=rund&p_run=42188&x=0&y=0

Trigger Clusters InfoTrigger Class Mask: 1

Show/Hide Trigger Config FileVERSION: 2PARTITION: ALICEINPUTS:SPD1 SPD 0 20 18INTERACTIONS:DESCRIPTORS:spd1 SPD1CLUSTERS:3 1 SPD SDD SSD TPC TRD HMPID PMDPFS:NONEBCMASKS:NONECLASSES:spd1 1 spd1 3 {NONE} {NONE} 0 1

Plot 3: ITS status of Calibration

• DongJo say that he know what to put here

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Plot4: TPC + ITS track matching

• DongJo ???

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Plot 5: Cosmic Ray Pt distributions

• Rafael ( start here to see my slides about pt distibution)

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Run III Cosmic RayAliEn Catalogue LHC08b

At the beginning NO Quality Cuts appliedAlso the current situation with the alignment/calibration is such that the high-pt momentum measurements are practically random...

Charged Tracks reconstructed reading directly from the ESD cosmic ray

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Track Cut proposed to the first physics data (based in Monte Carlo)

References :Measuring the Pseudorapidity of Charged Particles using TPC, [ ALICE-INT-2007-005]ALICE Physics Performance Report [PPR Vol II ]C. Jorgensen, talks in “Preparation for first Physics with ALICE” meeting at CERN March 2006

+ track inside the beam pipe

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Track Selection for cosmic ray …

Not used for cosmic ray ….

+ track inside the beam pipe

But still using this configuration I rejected all cosmic tracks !!! 8

Explanation !!

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Cov22 Cut < 2 cm2

Redefined Track Selection for cosmic ray …

Not used for cosmic ray ….

+ track inside the beam pipe

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Control Plots in one job

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We have now this control plots included in our ALICE Jyvaskyla task train

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Cuts Effect on cosmic ray Pt distribution

Comments from discussion with Jouri Belikov

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We should keep in mind that (by necessity) we are currently running with only partially calibrated TPC, partially re-aligned ITS, and without any relative TPC-ITS re-alignment...Under such conditions, all the "roads" in the tracking are artificially and significantly enlarged. This may explain your observation that the cut on the elements of the cov. matrix "kill" all the tracks.

The problem is that all these cuts were tuned on Monte Carlo, assuming the final calibration and re-alignment. We are not yet there.

As for the peak at ~0.050 GeV/c, I don't have any immediate explanation. For the real collisions, we will hardly go below 0.200 GeV/c. Still, it would be nice to understand it.

Today plot in the pt range 0.2 to 15 GeV/c

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Plot 2: TPC dE/dx distribution

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After Cuts

To Do list (working on …)

• Plot dE/dx before the cuts• Include in our analysis train event statistics plot • Check for more TPC QA info in the TPCQA.root file• Develop a macro to show all the QA histograms saved in the

train output file: jcorranQA.root • Summarize in one presentation what I learn from TPC track

reconstruction • Check the possibility to plot the correlation function. • Check about trigger info in the ESD files.• Scan new cosmic ray data.

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backup

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Cuts Influences study in p+p 14 TeV ALICE full simulations

Measuring the Pseudorapidity of Charged Particles using TPC, [ ALICE-INT-2007-005]

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Trk-to-vtx in p+p 14 TeV full ALICE simulations [not used for cosmic ray but important in the future data]

Measuring the Pseudorapidity of Charged Particles using TPC, [ ALICE-INT-2007-005]

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Plots 1: example of cosmic Ray Event

20 Marian Ivanov. ALICE Week July 2008