HyCal reconstruction: current situation and future tasks . V. Mochalov, IHEP (Protvino)

1. HyCal reconstruction: current situation and future tasks. V. Mochalov, IHEP (Protvino)

2. Part I. Calibration issues • HyCal reconstruction code • Cluster reconstruction • Timing in HyCal • HyCal Energy Calibration • Snake Calibration and short term stability • Physics Calibration and long term stability • HyCal position reconstruction • Methods • Investigations V. Mochalov. HyCal Status

3. Part II. Physics and planning • Physics • Status • Methods • Detector stability • Required checks of the detector • Required input information from other sources • Calculation efficiencies • Planning V. Mochalov. HyCal Status

4. Cluster code done • Methods incorporated to the program for Cluster • 3 different methods of coordinate reconstruction – I. Larin (see Kelly talk) • Depth correction for coordinate reconstruction (photon shower) I. Larin • Energy correction (from calibration) I.Larin • Island algorithm • Description of the glass shower shape • Method to calculate shower chi^2 • Shower leakage outside detector V. Mochalov. HyCal Status

5. Depth correction (Ilya) V. Mochalov. HyCal Status

6. Energy correction (Ilya) • Should be recalculated because of new tagger calibration. V. Mochalov. HyCal Status

7. Glass shower shape V. Mochalov. HyCal Status

8. Cluster code to do. • Cross-check of new cluster code (Dustin) • Check shower leakage outside (recomendations from soft. techn.) • Introduce shower leakage inside • Shower shape for PWO required • Study energy and coordinate reconstruction in transition region • Correction on beam angle and position • Introduce leakage inside “holes” • Introduce “electron depth (and energy?) correction” • Overlapping showers algorithm V. Mochalov. HyCal Status

9. Timing in HyCal done • Package to reconstruct time for HyCal triggers was developed (Ilya, Dustin and Vasiliy) • Time calibration (Ilya and Dustin) • Functions to search • Horizontal and vertical coincidence • Clusters with the same time • Coincidence between Cluster and tagger V. Mochalov. HyCal Status

10. Pair hits in PWO V. Mochalov. HyCal Status

11. Timing calibration accuracy • Efficiency is small: V. Mochalov. HyCal Status

12. Timing links to do • Cross-check code • Study and define all required cuts • Study efficiency of the timing reconstruction (and time offsets??) using snake calibration data V. Mochalov. HyCal Status

13. Snake calibration status • Was done by Ilya for energy about 2 GeV • Energy resolution about 1.7% (except ROC4) for PWO and 4% for glass. • Close to expected • But should be repeated V. Mochalov. HyCal Status

14. Snake calibration to do • Repeat calibration due to • Take into account actual photon energy: • New tagger calibration constants • electron beam energy (Hall C) • Take into account leakage • Use all energy range for calibration • Repeat energy dependence • Final study of energy resolution using calibration data, including dependence on beam energy, individual for channels ... (prepare all required for publication). V. Mochalov. HyCal Status

15. Short time stability • Left – Ilya found the effect on LMS • Possible pile-up and rate dependence effect (Kelly) • LMS dependence (Dustin) V. Mochalov. HyCal Status

16. Long term stability • Comparison of the first and second snake calibrations (electron and LMS) – Dustin • LMS correction • Compton calibration data (Elena) • Single arm Compton for production runs • Pair production • pi-0 data V. Mochalov. HyCal Status

17. Compton conclusions • Possibility to use calibration (resolution is close to 1.7/sqrt(E)%) • Clearly seen changes on time • Difference between photon and electron (need to check using pair production) • LMS is correlated, accuracy should be improved • Final tagger reconstruction is required to finish • Beam position and angle is required to finish • Need to study possibility of single-arm Compton • Pair production calibration is very important V. Mochalov. HyCal Status

18. Position reconstruction • 3 different methods were introduced. • Compton data showed the best result for logarithm method. • Kelly investigated 3 different methods for calibration data • Depth correction is done for photon – the same procedure is required for electrons • Transition region study next month V. Mochalov. HyCal Status

19. Physics status • First version of skim files for pi0 is ready (3.1M pi0's) • Compton skim files: 2-nd versions is preparing • New versions will be created when final bank structure will be prepared. • Methods for correct mass and energy are prepared by Ilya • Methods to calculate number of pi0 are prepared by Ilya V. Mochalov. HyCal Status

20. Energy and mass constraint methods (Ilya) V. Mochalov. HyCal Status

21. pi-0 distributions (Ilya). V. Mochalov. HyCal Status

22. Detector stability and required checks • DAQ errors and it's recovery • Sparcification cut investigation (Nick's talk) • Bad/noisy channels (ADC's) • Trigger group stability • Trigger threshold and the stability V. Mochalov. HyCal Status

23. Information required from other sources • For calibration: • Actual electron beam energy-> tagger energy • For physics calibration and physics • Beam position on the detector • Beam position (and angle) on the target • Information not used now: • Slow control, including temperature and humidity V. Mochalov. HyCal Status

24. Efficiency of the reconstruction • Trigger efficiency for whole detector and each strip/quadrant on energy • Influence of the different cuts on reconstruction efficiency: • Timing cuts; • Cluster energy cuts; • Elasticity cuts; • ... V. Mochalov. HyCal Status

25. Planning: Snake Calibration • Preparation for final calibration: • Finish tagger reconstruction – include beam energy (Eric?) • Software (Leakage of the cluster): • Prepare shower shape for PWO (Vasiliy) • Investigate leakage procedure (see recommendations from software technical meeting). • Add shower leakage inside calorimeter (Vasiliy) • Add shower leakage to holes (Vasiliy) • Find bad/noisy channels and describe them as holes (who?) • Finish sparcification cuts (Dustin?) V. Mochalov. HyCal Status

26. Planning: Snake Calibration (ctd) • Software (timing in the calorimeter) • Check time calibration for strips (quadrants) • Study and select time windows for cluster • Run final snake energy calibration for all energies • repeat energy dependence for each channel (Vasiliy+?) • Prepare Figures for publication concerning energy resolution of the detector (Vasiliy) • LMS calibration (?) • Study also the timing and trigger inefficiencies(?) V. Mochalov. HyCal Status

27. Compton calibration (Elena) • Preparations for final Compton calibration procedure: • Beam position and angle required !!! • Final tagger energy reconstruction • Software: add matrix inversion method. • Compton calibration coefficients for Compton data: • Comparison with snake calibration • Comparison of the LMS and Compton calibration • Compare different coordinate reconstruction methods • Single arm Compton Calibration on Compton (and production!?) runs • Pair production calibration is required (who ?!!! ) V. Mochalov. HyCal Status

28. Physics planning • Software: • Finish coordinate reconstruction procedure • Transition region coordinate • DAQ errors • Study all possible inefficiencies in reconstruction • Compton cross-section (compare with theory) • Veto inefficiency • Single arm compton • Pair production cross-section (compare with theory) V. Mochalov. HyCal Status

29. If compton and pair production are compatible with theory we are ready for π0 data. V. Mochalov. HyCal Status