ALICE Offline Week: Summary of Key Changes

1. C. Oppedisano, 8 July 2008, ALICE Offline Week ZDC offline code: status report C. Oppedisano • OUTLINE • Geometry • Raw data • Detector algorithms • Shuttle preprocessor and OCDB • Reconstruction • ESD • classes for QA

2. C. Oppedisano, 8 July 2008, ALICE Offline Week GEOMETRY MACHINE LUMINOMETER ALICE IP RECOMBINATION CHAMBER ZPA ZNA ALICE barrel ZDC side C ZDC side A 230 m AliZDCv3 ZDCs on both sides implemented (in previous version only side C was there)  Beam pipe geometry on side A finalized with the implementation of the recombination chamber placed before the ZDC location  Overlaps/extrusions corrected (thanks to Andreas!) Side A geometry @ ZDC location  Full geometry when ZDC is initialized in AliRoot geometry

3. C. Oppedisano, 8 July 2008, ALICE Offline Week Relevant change in the code • “THE CHANGE” • Before commissioning “static” mapping of ADC channels was foreseen • During the commissioning need to change the signal cabling into ADC modules, possibility to add a module... •  the cabled channels and the corresponding physics signals written together with the raw data (in the StartOfData event) • Dump of StartOfData event: • ***************************************** • DUMP OF SOR EVENT • 0 0xff000000 • 1 0x00000118 GEO: 0 type: 1 channels: 24 • 2 0x00000002 ch 0: kZNAC • 3 0x80000002 ch 0: kZNAC Low range • 4 0x00010003 ch 1: kZNA1 • 5 0x80010003 ch 1: kZNA1 Low range • 6 0x00020004 ch 2: kZNA2 • 7 0x80020004 ch 2: kZNA2 Low range • the mapping is directly read from raw data by the DAs that run on the LDC and are written in the OCDB • from raw data to DAs into OCDB objects through the Shuttle preprocessor... module geographic address + no. of cabled signal channel + physics signal (ZNA - tower 1)

4. C. Oppedisano, 8 July 2008, ALICE Offline Week RAW DATA • AliZDCRawStream class updated •  decoding of StartOfData event (accessible from DAs that run on LDC) • Other features added to the class: • reading of the CDH  block attributes providing the run type in STANDALONE runs  L1 trigger message: test of the software calibration bit (the data format is different in PHYSICS runs and in STANDALONE CALIBRATION runs) • test the read-out card messages and use flags to decide if the events (sub-events) are correctly written • scaler decoding implemented (used mainly to count trigger rates) Test on simulated/real raw data is under way The “original” class has already been used to read all the calibration data collected during the commissioning of the hadronic ZDCs

5. C. Oppedisano, 8 July 2008, ALICE Offline Week DAs & OBJECTS IN OCDB In every run the mapping of the cabled ADC channels and the physics signal is read and can be written (if changed!) in the OCDB  AliZDCChMap object NEW!!! We have very different needs/aims in p-p and in A-A!!! p-p  ZDCs don’t provide triggers, no trivial way to provide energy calibration NEW!!! Pb-Pb  ZDC trigger detectors, centrality variables reconstruction, energy calibration from physics measurement

6. C. Oppedisano, 8 July 2008, ALICE Offline Week DAs (I) • The DAs have been updated/implemented according to the changes introduced in AliZDCRawStream class 4 DAs implemented • ZDCPEDESTALda.cxx RUN type: STANDALONE_PEDESTAL input: 96 1-dim. histos + 48 2-dim histos + StartOfData event for the mapping • output: ZDCPedestal.datASCII file containing 144 pairs of floats: • 48 pairs of float for in-time signals  mean value +  • 48 pairs of float for out-of-time signals  mean value +  • 48 pairs of parameters from fit of the correlation in-time vs. out-of-time • ZDCChMapping.datASCII file with the mapping of the ADC modules • ZDCLASERda.cxx • RUN type: STANDALONE_LASER • input: 2 1-dim. histos from the reference PMTs used to check the signal stability • + StartOfData event for the mapping • needs: ZDCPedestal.dat as input • output: ZDCLaser.datASCII file containing: • 4 pairs of float for reference signals  mean value +  • ZDCChMapping.datASCII file with the mapping of the ADC modules

7. C. Oppedisano, 8 July 2008, ALICE Offline Week DAs (II) • ZDCEMDda.cxx • RUN type: STANDALONE_EMD • input: 28 1-dim. histos from EM dissociation events • StartOfData event for the mapping • needs: ZDCPedestal.datas input • output: ZDCEMDCalib.datASCII file containing: • 4 pairs of float for in-time reference signals  mean value +  • ZDCChMapping.datASCII file with the mapping of the ADC modules • NOTES •  no energy calibration from data foreseen for the EM calorimeter!!!! • in p-p there is no DIRECT way to extrapolate energy calibration factors from data  for p-p data initially factor calibration = 1 will be used! • ZDCMAPPINGda.cxx • RUN type: all the others • input: StartOfData event • output: ZDCChMapping.datASCII file with the mapping of the ADC modules • Final tests going on before re-starting the validation procedure ONLY IN Pb-Pb!!!

8. C. Oppedisano, 8 July 2008, ALICE Offline Week SHUTTLE PREPROCESSOR (I) • AliZDCPreprocessor updated • PROCESSED RUN TYPES FXS FILE TO BE RETRIEVED • STANDALONE_PEDESTAL  ZDCPedestal.dat, ZDCChMapping.dat • STANDALONE_EMD  ZDCEMDCalib.dat, ZDCChMapping.dat • STANDALONE_LASER  ZDCLaserCalib.dat, ZDCChMapping.dat • any other run tpe  ZDCChMapping.dat For ALL RUN types: DCS alignment object in OCDB position of the 4 hadronic ZDCs AliZDCChMapping calibration object in OCDB DAQ ADC channel/physics signal map

9. C. Oppedisano, 8 July 2008, ALICE Offline Week SHUTTLE PREPROCESSOR (II) For the other RUN TYPES the above specified files in DAQ FXS are processed • a calibration object is written in the OCDB depending on the RUN type: STANDALONE_PEDESTAL  Calib/Pedestals  AliZDCPedestals object STANDALONE_LASER  Calib/LaserCalib  AliZDCLaserCalib object STANDALONE_EMD  Calib/Calib  AliZDCCalib object (in Pb-Pb) In p-p runs, the calibration coefficients are set to 1 WITHOUT processing any FXS file Shuttle test setup Succesfully tested for the already implemented RUN TYPES (STANDALONE_PEDESTAL and STANDALONE_EMD) Production @ P2 If the DCS DP are found in the DCS DB, they are correctly processed! Unfortunately at the moment the DCS DP aren’t always written  DCS problem, experts investigating!

10. C. Oppedisano, 8 July 2008, ALICE Offline Week CALIBRATION OBJECTS (I) • AliZDCChMapping • object containing the mapping of the ADC modules and the corresponding physics signals (needed in reconstruction) • data members • Int_t fADCModule[48]; // ADC module • Int_t fADCChannel[48]; // ADC channel • Int_t fDetector[48]; // detector • Int_t fSector[48]; // sector •  AliZDCPedestal • calibration object giving parameters for pedestal subtraction from ADC spectra • data members • Float_t fMeanPedestal[48]; // Mean pedestal values • Float_t fMeanPedWidth[48]; // Mean pedestal widths • Float_t fOOTPedestal[48]; // "Out of Time" pedestal values • Float_t fOOTPedWidth[48]; // "Out of Time" pedestal widths • Float_t fPedCorrCoeff[2][48]; // Fit of correlation in-time vs. out-of-time •  AliZDCLaserCalib • calibration object to correct for aging or damaging effects, monitored by means of 2 reference PMTs (1 per side) • data members • Float_t fRefPMSignal[2]; // RefPM signal mean values Float_t fRefPMSignalWidth[2]; // RefPM signal width

11. C. Oppedisano, 8 July 2008, ALICE Offline Week CALIBRATION OBJECTS (II) ZN fibres connection ZN1 ZN2 ZN3 ZN4 ZNC Simulated spectrum of EMD events •  AliZDCCalib(only for Pb-Pb data) • E calibration factors from EM dissociation events  the conversion factor ADC channels  Energy • can be calculated from the fit of 1 neutron (proton) • peak in ZN (ZP) spectrum • relative calibration coefficients for the 5 PMTs of each hadronic ZDC from EM dissociation events  algorithm for the relative calibration of the 4 tower PMTs tested on simulated data  the sum of the 4 calibrated tower PMTs is then equalized w.r.t. the “common” PMT • data members • // --- E calibration • Float_t fEnCalibration[6]; // Coeff. for energy calibration • // --- Coefficients for tower calibration • Float_t fZN1EqualCoeff[5]; // Equalization coefficients for ZN1 PMTs • Float_t fZP1EqualCoeff[5]; // Equalization coefficients for ZN1 PMTs • Float_t fZN2EqualCoeff[5]; // Equalization coefficients for ZN1 PMTs • Float_t fZP2EqualCoeff[5]; // Equalization coefficients for ZN1 PMTs 2.7 5.4 8.1 10.8 E (TeV)

12. C. Oppedisano, 8 July 2008, ALICE Offline Week RECONSTRUCTION • AliZDCReconstructor class • 2 different algorithms implemented • AliZDCReconstructor::ReconstructEventpp • AliZDCReconstructor::ReconstructEventPbPb • RECONSTRUCTION STEP CALIBRATION OBJECT USED • p-p pedestal subtraction AliZDCPedestal object from OCDB • signal equalization [AliZDCCalib +] AliZDCLaserCalib from OCDB • signals summed • Pb-Pb pedestal subtraction AliZDCPedestal object from OCDB • signal equalization AliZDCCalib + AliZDCLaserCalib from OCDB • energy calibration AliZDCCalib object from OCDB • signals summed • centrality variables reco AliZDCRecoParamPbPb class • crucial to know the BEAM TYPE during reconstruction to select the algorithm • waiting for the “official” decision, for the moment p-p reconstruction has been forced in AliZDCReconstruction

13. C. Oppedisano, 8 July 2008, ALICE Offline Week AliZDCRecoParam • AliZDCRecoParam base classand 2 derived classes implemented: • AliZDCRecoParampp  data member Float_t fBeamEnergy; // beam energy • AliZDCRecoParamPbPb containing functions/parameters used to reconstruct the centrality variables (Nspec, b) from the measured energies  some of the data members // *** PARAMETERS FOR Pb-Pb COLLISIONS // --- Functions to evaluate centrality variables from defined functions TF1* fZNCen; //! Nspectator n true vs. EZN TF1* fZNPer; //! Nspectator n true vs. EZN TF1* fZPCen; //! Nspectator p true vs. EZP TF1* fZPPer; //! Nspectator p true vs. EZP TF1* fZDCCen; //! Nspectators true vs. EZDC TF1* fZDCPer; //! Nspectators true vs. EZDC TF1* fbCen; //! b vs. EZDC TF1* fbPer; //! b vs. EZDC TF1* fZEMn; //! Nspectators n from ZEM energy TF1* fZEMp; //! Nspectators p from ZEM energy TF1* fZEMsp; //! Nspectators from ZEM energy TF1* fZEMb; //! b from ZEM energy // --- Coefficients for centrality selection from ZEM signal Float_t fZEMEndValue; // End point value of ZEM energy spectrum Float_t fZEMCutFraction; // Fraction of ZEM energy spectrum used to cut

14. C. Oppedisano, 8 July 2008, ALICE Offline Week ESD (I) AliESDZDCclass  data members • EZNA, EZPA, EZNC, EZPC Double32_t fZDCN1Energy; // reconstructed energy in the neutron ZDC Double32_t fZDCP1Energy; // reconstructed energy in the proton ZDC Double32_t fZDCN2Energy; // reconstructed energy in the neutron ZDC Double32_t fZDCP2Energy; // reconstructed energy in the proton ZDC getters: GetZDCN1Energy(), GetZDCP1Energy(), GetZDCN2Energy(), GetZDCP2Energy() 1 and 2 refers respectively to the C (dimuon) and A sides • energy detected in ZEM1 and ZEM2 Double32_t fZDCEMEnergy; // signal in the electromagnetic ZDCs Double32_t fZDCEMEnergy1; // 2nd EM signal, cannot change fZDCEMEnergy to array (not backward compatible) getters: GetZDCEMEnergy(i) • in p-p these ESD DO NOT CONTAIN THE ENERGIES!!! BUT signals PROPORTIONAL to the energies (in ADC channel units)

15. C. Oppedisano, 8 July 2008, ALICE Offline Week ESD (II) • calibrated signal for each PTM of the hadronic ZDCs 5 signal x 4 detectors x 2 gain chains of the ADC = 40 values Double32_t fZN1TowerEnergy[5];// reco E in 5 ZN1 sectors - high gain chain Double32_t fZN2TowerEnergy[5];// reco E in 5 ZN2 sectors - high gain chain Double32_t fZP1TowerEnergy[5];// reco E in 5 ZP1 sectors - high gain chain Double32_t fZP2TowerEnergy[5];// reco E in 5 ZP2 sectors - high gain chain Double32_t fZN1TowerEnergyLR[5];// reco E in 5 ZN1 sectors - low gain chain Double32_t fZN2TowerEnergyLR[5];// reco E in 5 ZN2 sectors - low gain chain Double32_t fZP1TowerEnergyLR[5];// reco E in 5 ZP1 sectors - low gain chain Double32_t fZP2TowerEnergyLR[5];// reco E in 5 ZP2 sectors - low gain chain Double32_t fZNACentrCoord[2];// Coordinates of the centroid over ZNC Double32_t fZNCCentrCoord[2];// Coordinates of the centroid over ZNA getters:GetZN1TowerEnergy() and so on… Moreover the signal of the neutron ZDC is used to reconstruct event by event the centroid of spectator neutrons over the detector front face in order to provide a first order estimate of the reaction plane  methods to get the coordinates of the centroid given the number of detected spectators provided Double32_t * GetZNCCentroid(int NspecnC); Double32_t * GetZNACentroid(int NspecnA); • Npart Short_t fZDCParticipants;// number of participants estimated by the ZDC getter: GetZDCParticipants()  This datum has NO MEANING in p-p!!!

16. C. Oppedisano, 8 July 2008, ALICE Offline Week QA histograms - Simulation ZNA ZN fibres connection to PMTs ZNA ZN1 ZN2 ZN3 ZN4 ZNC • AliZDCQADataMakerSim • HITS histograms •  spectator centroid over neutron ZDCs • DIGITS histograms • ZNA(C) and ZPA(C) ADC spectra (ZNA1+ZNA2+ZNA3+ZNA4+ZNC) • summed tower PTM signals (ZNA1+ZNA2+ZNA3+ZNA4) • signal from common PTM (ZNC) • both for low and high gain chains

17. C. Oppedisano, 8 July 2008, ALICE Offline Week QA histograms - Reconstruction ZP side C ZN side C • AliZDCQADataMakerRec • RAW histograms • ZNA(C) and ZPA(C) raw data ADC spectra • summed tower PTMi signals (ZN1+ZN2+ZN3+ZN4) • signal from common PTM (ZNC) • both for low and high gain chains ESD histograms • ZNA(C) centroid • total energy in the 4 hadronic ZDCs • energy in the 4 tower PMTs • energy in the common PMTs

18. C. Oppedisano, 8 July 2008, ALICE Offline Week QA checker AliZDCQAChecker SIMULATION HITS  check passed if |mX(Y) values| < 0.2 cm DIGITS  check that ZNA and ZNC have the same mean value @ 1s level  check that ZPA and ZPC have the same mean value @ 3s level  check that PMC and i(PMQi)difference < 10% RAW & ESD Similar checks to the ones performed on the DIGITS: comparison between total response on the 2 sides  check that the sum of the 4 PTMs is comparable with the PMC signal

19. C. Oppedisano, 8 July 2008, ALICE Offline Week OPEN TASKS (I) • DAs • From February debugging of the ZDC read-out card to solve unexpected problems(not seen during December runs) that didn’t allow to acquire data • Work still ongoing, from last week we are able to run in STANDALONE mode!!! •  delay in DA validation • Change in AliZDCRawStream class • already validated DAs updated, new DAs implemented • re-start the validation procedure(DAQ team warned)

20. C. Oppedisano, 8 July 2008, ALICE Offline Week OPEN TASKS (II) Shuttle preprocessor • DCS system used in STANDALONE runs only from last week • still some problem to be checked (already reported to Chiara and Jan), Grazia Luparello is working on the item with the help of CERN DCS experts Reconstruction Beam type info needed, waiting for a decision (Cvetan keeps us informed) • DA for Shuttle • Postpone the done date to the end of August • AliRoot and condition data what are we supposed to do?

21. C. Oppedisano, 8 July 2008, ALICE Offline Week Tasks that can be closed?!? • List of DCS for Shuttle  DCS list for Shuttle was provided to Alberto Colla months ago http://aliceinfo.cern.ch/Offline/Activities/Shuttle/ZDC_DCS.html • FXS file list  the list is ready… • PROCESSED RUN TYPES FXS FILE TO BE RETRIEVED • STANDALONE_PEDESTAL  ZDCPedestal.dat, ZDCChMapping.dat • STANDALONE_EMD  ZDCEMDCalib.dat, ZDCChMapping.dat • STANDALONE_LASER  ZDCLaserCalib.dat, ZDCChMapping.dat • any other run tpe  ZDCChMapping.dat