1. L0 trigger update Bruno Angelucci INFN & University of Pisa

2. “Feasible for first 2014 run” L0 trigger ▫ Detectors involved ▫ Signal handling ▫ Primitive generation L0 rates and efficiencies ▫ Study of crucial subdetectors parameters ▫ Rejecting power of vetoes 2

3. Software used ▫ NA62MC and NA62Reconstruction rev301 100k πνν events + 100k of 6 K main decays + 4 muon halo components + beam pions no accidentals ▫ NA62MC and NA62Reconstruction rev314 10k πνν events + 10k of 6 K main decays accidentals superimposed to central event at generation level (±150 ns) L0 trigger Analyzer developed under NA62Analysis FW 3

4. RICH primitive ▫ Multiplicity counting hits in time bins  Low and High multiplicity CHOD primitive ▫ Coincidence in space (correspondent quadrants) ▫ Coincidence in time ▫ Multiplicity grouping coincidences in time bins  Max hit multiplicity  Quad multiplicity MUV3 primitive ▫ Time coincidence of 2 PMs of same pad LKr primitive ▫ Combining cells in SuperCells (SC) in same time bin ▫ Combining SCs in clusters: same time bin, adjacent ▫ Thresholds both for cell and SC energy ▫ 2 or more clusters in time LAV12 primitive ▫ Hits with low and high threshold channels firing ▫ Slewing timing correction ▫ Offset of different layers 4

5. CHOD Primitive multiplicity All πνν decays Signal ( πνν passing conditions) 5

6. 6

7. Kinematic requests ▫ 15 <P π < 35 (GeV/c) ▫ 105 < Z vtx < 165 (m) ▫ 0 <M 2 miss < 0.01 || 0.026 <M 2 miss < 0.068 (GeV 2 /c 4 ) Acceptance requests ▫ No pion decay before LKr ▫ Pion in CHOD and MUV3 acceptance ▫ Pion not in LAVs acceptance Resulting πνν acceptance: order of 10% 7

8. The goal is to check efficiencies and rates varying one parameter at a time keeping fixed all others RICH ▫ Time bin ▫ Low multiplicity threshold ▫ High multiplicity threshold CHOD ▫ Time bin ▫ “Max” multiplicity threshold ▫ Quadrant multiplicity threshold LKr ▫ Cell energy threshold ▫ SuperCell energy threshold ▫ Time bin for cell time ▫ Δ t for SC and cluster matching L0TP primitive matching time 8

9. No accidentals 9

10. With accidentals 10

11. With accidentals 11

12. With accidentals 12

13. No accidentals 13

14. With accidentals 14

15. RICH ▫ Time bin = 3.125 ns ▫ Low multiplicity threshold = 4 ▫ High multiplicity threshold = 28 CHOD ▫ Time bin = 1.5625 ns ▫ “Max” multiplicity threshold = 10 ▫ Quadrant multiplicity threshold = 2 LKr ▫ Cell energy threshold = 0.1 GeV ▫ SuperCell energy threshold = 0.7 GeV ▫ Time bin for cell time = 12.5 ns ▫ Δ t for SC and cluster matching = ±6.25 ns L0TP primitive matching time = ±(1.5625,3.125) ns 15

16. With accidentals 0: RICH & CHOD & !MUV3 & !LKr & !LAV 1: RICH & CHOD & !LKr & !LAV 2: RICH & CHOD & !MUV3 & !LAV 3: RICH & CHOD & !MUV3 & !LKr 16 No accidentals

17. ▫ Efficiency: 91.1 ± 0.3 % ▫ Total rate: 360 ± 11 kHz With accidentals (halo missing) ▫ Efficiency: 76.7 ± 1.3 % ▫ Total rate: 425 ± 15 kHz 17

18. 18

19. With accidentals 19

20. With accidentals 20

21. With accidentals 21

22. With accidentals 22

23. With accidentals 23

24. With accidentals 24

25. With accidentals 25