2. Simulation activities in India: students working on various topics.. Partha(VECC), Hemen (GU) : Trigger, SIS100, physics simulation Bipasha (CU): dynamic range simulation, J/Psi physics at FAIR Arun: Geometry study Manish, Irshad (Jammu U) EVO meet every Thursday: co-ordinator: Z. Ahammed

3. 9th September,2009CBM-Muon Meeting(EVO)2 Study of Manual Segmentation of MuCh ARUN PRAKASH High Energy Physics Lab Department of Physics Banaras Hindu University Varanasi-221005

4. 9th September,2009CBM-Muon Meeting(EVO)3 Outline Manual Segmentation Study Results Future Plan

5. Approach: Reduce total no of pad sizes to 0.5 Milion Single track (and muon) efficiency should not change with highest granularity case

6. 9th September,2009CBM-Muon Meeting(EVO)5 Standard Geometry  Cbmroot trunk version  Embedded 1000 central events Au+Au at 25 AGeV  Standard MuCh: 13 layers  Total length : 3.4m

7. 9th September,2009CBM-Muon Meeting(EVO)6 Manual Segmentation A.2x.4 to 1.6 x 3.2 3 regions Rest all: 1.6 x 1.6 1 region Total no of pads: 577536

8. 9th September,2009CBM-Muon Meeting(EVO)7 Manual Segmentation(contd...) B.2 x.4 One region Rest all 1.6 x 1.6 (one region each) No of pads: 1211392

9. 9th September,2009CBM-Muon Meeting(EVO)8 Manual Segmentation(contd...) C 2 regions:.2 x.4.4 1.6 Rest 1.6 x 1.6. 1 region No of pads: 628736

10. 9th September,2009CBM-Muon Meeting(EVO)9 Manual Segmentation(contd...) D 3 regions:.2 x.4 to.8 x 3.2 Rest: 1.6 x 1.6, one region Total no of pads: 574464

11. 9th September,2009CBM-Muon Meeting(EVO)10 Manual Segmentation(contd...) E 3 regions:.2 x.4 to 1.6 to 3.2 3 regions:.8 x 1.6 to 3.2 to 3.2 2 regions: 1.6 x 3.2 to 3.2 to 3.2 Rest 3.2 x 3.2 Total no of pads: 195840

12. 9th September,2009CBM-Muon Meeting(EVO)11 Efficiency of Muons(standard geo) Presented earlier

13. Why no change in efficiency? Can we work with largest pad size? Take one region/station, double pad size for every subsequent station Change track selection criteria and see the effect

14. Manual Segmentation STATION PAD SIZE(cm) 123456 A0.25x0.250.45x0.450.6x0.60.8x0.81.25x1.25 B0.5x0.50.9x0.91.2x1.21.6x1.6 2.5x2.5 C1.0x1.01.8x1.82.4x2.43.2x3.2 5.0x5.0 D 6.0x6.07.0x7.08.0x8.09.0x9.010.0x10.0

15. 4 different pad sizes PAD SIZE (1 st ) PARAMETERS 0.25X0.25(A)0.5X0.5(B)1X1(C)5X5(D) # of Digis2210219120601113 # of Global track2335240129255130 # of Much Track1994208626494962 (8hits)Eff (STS+MUCH) 0.94 0.77 (6hits)Eff (STS+MUCH) 0.84 0.73 Eff(10hits) (STS+MUCH) 0.89 Total no of pads2,400,480691,040170,37615,768

16. 9th September,2009CBM-Muon Meeting(EVO)15 Future Plan To look into other parameters like invariant mass, acceptance plot,momentum distribution etc. Add clustering Study auto-segmentation

17. Dynamic Range of Much Bipasha Bhowmick University of Calcutta, Kolkata & Partha Pratim Bhaduri,VECC,Kolkata

18. DYNAMIC RANGE ● DYNAMIC RANGE It is a term used frequently in numerous fields to describe the ratio between the smallest & largest possible values of a changeable quantity (such as measurable deposited energy)

19. Aim & algorithm Dynamic range is a quantity essential for design of the read-out chips. Determination of the energy deposition at each cell of the muon chambers ( in terms of MIP,as muons give MIP signal). Take different cell sizes (2mm. – 4cm.) & find out the fraction of multiple-hit cells & singly-hit cells for particles generated by UrQMD. Optimize the cell size based on multi-hit fraction. For the optimal cell size find cell energy deposition (E_dep) both for single muons (MIP spectra) & UrQMD particles. Apply different MIP cuts & calculate the loss due to saturation. Apply different hit cuts to observe the effect on tracking.

20. Fraction of multiple-hit cells= (total # of cells having >1 hit)/ (total # of cells hit) Optimal cell-size : 4mm. for inner stations, 4cm. For outer stations (stn 12 onwards)

21. Single muon energy deposition spectra : Fitted with Landau distribution MIP value : 0.197 KeV (MPV of the Landau) Station# 1 Cell size : 4mm. Station# 12 Cell size: 4cm.

22. E_dep by UrQMD particles Station# 1 Cell size : 4mm. Station# 12 Cell size: 4cm.

23. Saturation loss : part of the energy spectra above the selected energy deposition cut (in terms of MIP) value MIP cut: E_dep cut (keV)/MIP value(= 0.197 keV)

24.  OBSEVATION number of tracks is affected to a permissible amount(2.78% of the total tracks) if we reject 2% of the total hit in each station Statistics : UrQMD : 50 central events Single muons : 50 events with 50 mu+ & 50 mu- in the momentum range 2.5GeV- 25GeV generated at angle 2.5 to 25 degree using box- generator

25. Comparison of percentage of track lost using different signals as input Varying the number of muon tracks added in embedding

26. Trigger simulation Partha Pratim Bhaduri VECC, India

27. CbmRoot Version: Trunk version Much geometry : Standard Geometry 2 layers in 5 stations Distance between layers 10 cm. Gap between absorbers 20 cm 3 layers at the last trigger station Total 13 layers Total length of Much 350 cm Signal : J/  decayed muons from Pluto Background : minimum bias UrQMD events for Au+ Au at 25 GeV/n Much Hit producer w/o cluster & avalanche L1(STS) & Lit (Much) tracking with branching Input : reconstructed Much hits Simulation Absorber thickness (cm): 20 20 20 30 35 100

28. Trigger algorithm Take 3 hits from the trigger station with one from each of the 3 layers & fit with st. line both in X-Z & Y-Z plane passing through the origin (0. 0) i.e. X = m 0 *Z ; Y=m 1 *Z Make all possible combinations Find  2 & apply cut on both  2 X &  2 y Hit combination satisfying the cuts is called a triplet. Hits once used for formation of a triplet is not used further. Find m 0 & m 1 of the fitted st. lines Define a parameter α=√(m 0 2 +m 1 2 ) Apply cut on α Magnetic field (0,0,0) (0,0.0) 11 12 13 Trigger station

29. Specification of cuts Cut 1: at least 1 triplet/event Cut 2 : at least 2 triplets/event Cut 3 : at least one of the selected triplets satisfy alpha cut Cut 4 : at least two of the selected triplets satisfy alpha cut Events analyzed: 80k minimum bias UrQMD event for background suppression factor & 1k embedded minimum bias events for J/  reconstruction efficiency

30. Event Input Cut-1 Cut-2Cut-3 cut-4 Pluto10k7941296425701487 UrQMD80k26242559156 Event selection Set : 1 Cut Values :  2 x,y <=0.2 α>=0.183

31. Background suppression factor (B. S. F) Cut Events survived Statistical Error B. S. F 1 2624 1.95 % ~ 30 2 255 6.26 % ~314 3 91 10.4 % ~879 4 56 13.36 % ~1430 B. S. F = Input events (80,000) / events survived

32. Reconstructed J/  Trigger cut Reconstruction efficiency (%) no cut 29.3 % Cut 1 29.2 % Cut 2 24.5 % Cut 3 24.2 % Cut 4 15.3 % 1k embedded minimum bias events

33. Trigger Cut 1 (Reconstructed J/  : 292)

34. Trigger Cut 2 (Reconstructed J/  : 245)

35. Trigger Cut 3 (Reconstructed J/  : 242)

36. Trigger Cut 4 ( Reconstructed J/  : 153)

37. Observation Hit-triplets are made from last 3 layers of the trigger station, vertex included in the fitting. Systematic study of background suppression & number of reconstructed J/y & its phase space distribution on cut by cut basis has been done. Statistics will be increased to reduce the statistical error further. Using information from “Much-only” gives sufficient B. S.F (~1430). With the application of the 4 th trigger cut there is a decrease in signal reconstruction efficiency up to ~ 50 % Cut by cut investigation shows even up to the 3 rd trigger cut we have reasonable B. S. F (~879) but without decrease in signal reconstruction efficiency. Phase space distribution of the triggered & un-triggered sample shows that all the trigger cuts are unbiased.

38. Future Plans Prepare a look-up table for different values of cut parameters & corresponding values of B. S.F & signal reconstruction efficiency. Implementation of TRD in the present scheme. Study pad resolution effect. Formation of CbmMuchTrigger class to be run in chain.

39. SIS-100 simulation We have a HSD version with charm production, we are running that for generation of signal for SIS100 Will vary muon geometry (no of stations/pad- sizes) Arun (and Dr. Viyogi) will be at GSI working on this