True singles study

1. True singles study Qinzeng Peng Boston University 2008 May 21

2. inner outer 3mm 15cm Expected true single hits • Outer tile is smaller than inner tile • Coincidence area ≈ outer area • Expected outer singles ≈ 0 • Expected inner singles (see table below)

3. Experimental results from single hits • David’s elog 194 shows true outer single hit rate is unexpectedly big • singles come from muon decay.

4. Plots from David’s elog 194

5. Ratio of true single hits vs. pair number

6. comparison

7. Justin’s 3D plot view

8. Next nearest neighbors:15-20cm nearest neighbors:8-10cm Left Right Inner LG Bottom Inner Tile Outer Tile Outer LG Neighbors of one tile pair

9. General coincidences • Form coincidences within tile pairs and betweenneighbors. • Alignment of all channels by T0 offset • Sort all pulses by time • Eliminate later of coincidence pair (coin window=4 CLKs) • Group pulses inside dT Window=8 clock ticks

10. pair coinc. T true single How to group pulses coinc. alone single alone Within tile pair coinc.+single coinc.+coinc. All neighbors foreign coinc. single+coin. single+single Neighbor window=8, coincidence window=4

11. coincidence with neighbors after alignment

12. Ratio of true singles

13. Inside of true singles of inners

14. Inside true singles of outers

15. Ratio of coincidence

16. Number of pulses in neighbor window

17. Amplitudes of the inner tiles

20. Amplitudes of the inner tiles

23. Amplitudes of the outer tiles

24. Amplitudes of the outer tiles

25. Left Right Bottom Focus on single-single coinc.

26. Justin’s 3D plot view

27. Non-symmetric numbers in nearest neighbors for single outers -- pent sn 51

28. Non-symmetric numbers in nearest neighbors for single outers - hex sn 151

29. Left Right Bottom Single outer of hex

30. Left Right Bottom Single outer of pent

31. Ratios of 3 neighbors of outers – single+ single

32. Ratios of 3 neighbors of inners – single +single

33. Justin’s 3D plot view

34. summary • Some detectors not calibrated perfectly. • Not-symmetric of foreign coincidence for the outer singles.

36. Ratios of 3 neighbors of outers – single+All

37. Ratios of 3 neighbors of inners – single+All

38. Ratios of 3 neighbors of coin. – coin. + coin.

39. Ratios of 3 neighbors of coin. – coin. +all

40. neighbors for single inners- pent sn 60

41. Non-symmetric of neighbors for single inners - hex sn 200

42. DW’s elog 194

43. Coin with the ball • Each tile has 3 nearest neighbors: right, left, bottom (exclude 10 hex pairs around the entrance and exit pentagons) and they have the biggest numbers of coincidence. • Each tile has coincidence peaks with about 1/3 of tiles around the ball. (50 of 170)

44. Original dt_coin_neighbors

45. Dt_coin_neighbors after dt offset shift

46. How good is the dt offset shift ? • About 14 of 170 inners have dt_off_3neighbors > 4 CLKs after dt offset shift, but they are still smaller than 7.5 CLKs, so choose dtWindow = 8 CLKs is wise. • Bad channels are: 18 – 20 34 – 36 92 – 100 – 324 96 – 98 -- 100 268 – 322 280 – 334 324 -- 326

48. neighborAll.cppneighborAll.txt • for each group there are n+1 lines • first line: sn • next n lines: neighbors of sn ordered by distance • columns: sn, isRight, isLeft, isBottom, distance, theta(cos)

49. Time alignment for all channels • Shift outer tile of each pair (easy) • 170 inner tiles can be aligned up by single coincident hits with the neighbors • NO WFD reset during runs. • Runs selected: 57325-57425, end of run. And they have the same settings.

50. 3 nearest neighbors, 8-10cm 9 next closer neighbors, 15-20cm Coincidence w/ neighbors vs. distance