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RUN 2008 OPERA  events: Status Report

RUN 2008 OPERA  events: Status Report. M. Ieva on behalf of Bari Emulsion Lab. OPERA Collaboration Meeting, April 1st - 5th, 2009. Summary tables (updated to March 28th). * 2 / 9 single hadron stops. HF. B1009968 (tape, no µ candidate, still under investigation). Black CS.

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RUN 2008 OPERA  events: Status Report

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  1. RUN 2008 OPERA  events: Status Report M. Ieva on behalf of Bari Emulsion Lab OPERA Collaboration Meeting, April 1st - 5th, 2009

  2. Summary tables (updated to March 28th) * 2/9 single hadron stops

  3. HF

  4. B1009968 (tape, no µ candidate, still under investigation) Black CS B1005212 (tape, SB + TS done, working on reconstruction) Overview of pending events Total: 10 details in next slides B1117209 (HF, µ stop under investigation ) CC events with µ B1083436 (tape, possible edge-out, under investigation ) B1121253 (tape, HF > 14, problems in track reconstruction due to HF) B1120658 (HF, details in next slides) B1012652 (1/1 LNGS preds connected, only 1 seg (film 57), TS done, 2 µ cands to be validated in CS ) CC events no µ B1129069 (tape, SB running ) B1092404 (tape, SB running ) NC events B1051633+B1052615 (tape, HF, SB running)

  5. Event 229132071 (CC) – Brick 1120658 PENDING

  6. 1/2 LNGS predictions connected, 3 segments only (55-57), stop confirmed by TS and visual inspection TO DO: search for possible muon candidates in TS volume; re-analysis/measurement of CS

  7. Event 236770829 (CC) – Brick 1005212 (black CS) PENDING SB and TS done, muon stop in film 15 still under investigation green track: sx = 0.051 sy = 0.006

  8. Event 234996823 (CC) – Brick 1009968 (black CS) PENDING GS in films 52 ÷ 57, up to now no µ candidates confirmed, still working on reconstruction (very marginal event!)

  9. Event 235109819 (NC) – Brick 1018966 LOCATED! 2 out of 4 LNGS predictions successfully connected

  10. Scan back “red” track track stops in film 49 “black” track stops in film 57 TS volume 1 • measured area ~ 1cm2in 11 films (47 ÷ 57): • track stop confirmed in film 49 • by visual inspection the track is a e+e- pair from  conversion observed • in plastic base of film 49. TS volume 2 measured area ~ 1cm2 in 12 films (37 ÷ 46) Volume scan data analysis (films 37 to 57) Total nr of vertices: 61 (I.P.  20 m, DZ < 3900 m) No charged primary track: 10 - at least two tracks with nseg ≥ 3, DZ < 3000 m 0 - at least one track with nseg ≥ 3, DZ < 3000 m 3 - slopes of the line connecting vertex and e+e- pair  0.5 0

  11. TS volume 3 measured area ~ 9 cm2 in 10 films (27 ÷ 36) Final volume scan data analysis (films 27 to 57) • e+e- pair from • conversion from LNGS pred (film 49) 5-prongs vertex in base of film 29 i.p. 6.5 m X = 27329, Y =78650

  12. …from vertex recostruction all tracks confirmed by visual inspection and followed down tracks 1495 and 2697 searched for in CS for vertex validation track 1495 found, VERTEX CONFIRMED!

  13. Some nice events…

  14. Scan back p1, p3, p5 are passing-through p2 stops in film 51 p6 stops in film 57 p4 stops in film 34 TS volumes Volume 1, measured area ~ 1cm2 in 11 films (29 ÷ 39) Volume 2, measured area ~ 1cm2 in 11 films (22 ÷ 32) the parent track was followed back and found to be a passing-through track 3-prong vertex kink lead plate between films 26 and 27 i.p. 3.8 m lead plate between films 32 and 33 i.p. 2.6 m daughter: sx=-0.012 sy=0.281 parent: sx=-0.131 sy=0.048 Event 227917085 (CC) – Brick 1018630 6 out of 7 LNGS predictions successfully connected (no muon candidate) General scan of films 1 ÷ 4 (~ 2 cm2/film) searching for muon candidates (angular selection : ± 40 mrad w.r.t. ele preds) found 1 µ candidate extrapolated to CS and confirmed by visual inspection upstream brick extracted

  15. CS-brick connection(no muon candidate) slopes similar to charged primary track of 3 prong vertex in brick 18630: sx = - 0.038, sy = 0.063 P1 110320.95 11984.67 - 0,039 0,033 110313.55 12027.21 - 0.037 0.031 P2 110268.2 12056.14 - 0.056 0.105 110317.0 12041.46 - 0.029 0.099 slopes similar to one of passing-through tracks in brick 18630 : sx = - 0.02, sy = 0.08 primary vertex lead plate between films 55 and 56 i.p. 0.84 m X = 110363, y =11995 muon candidate p1 Upstream Brick 1036025 clear signal of track convergence in most downstream films, direct TS volume lead plate between films 55 and 56

  16. the parent track was followed back and found to be a passing-through track lead plate between films 53 and 54 i.p. 33.2 m X = 99668, y =7725 LNGS preds Event 234531427 (NC) – Brick 1051633 2 LNGS predictions successfully connected Scan back stop in film 55 TS results measured area ~ 1cm2in 11 films (47 ÷ 57)

  17. i.p. 1.0 m lead plate between films 25 and 26 parent track lead plate between films 41 and 42 i.p. 4.9 m muon candidate secondary vertex the parent track was followed back up to film 26 where it was found to stop additional TS performed around parent track stop Event 230771147 (CC) – Brick 1055609 tracks convergence was checked, predicted vertex position in lead plate between films 41 and 42, estimated i.p. ~ 60 m 2 LNGS predictions successfully connected (no muon candidate) primary vertex primary vertex SB skipped, Direct TS performed Muon candidate followed down to film 57 and confirmed in CS by visual inspection

  18. up to now, attention mainly devoted to event location; now, re-analysis of located events for decay search starting Brick scanning and analysis chain 0. Fog and thickness measurement • CS to Brick connection: •  pointed scanning (3x3 fov) around each CS pred • general scan (~16 cm2) for bricks with black CS •  visual check of found candidates • Scan-Back: •  with 2 or 3 or 4 lateral-marks depending on event type and fog density •  in case of problems, visual check of stopping point • Total Scan: •  until middle of March, scanning of 1cm2, 5 films up + 5 films down •  now, 1cm2, 5 films up + 10 films down • Volume reconstructionand analysis • Vertex confirmation •  visual inspection of vertex tracks in 2 films up + 2 films down 6. Quality check 7. Data publication to Central DB

  19. - list of published processes: - list of published reconstructions: Status of data publication up to now, 44 scanning processes (25 bricks) and 17 event reconstructions published to OPITA

  20. Lab news… • Software: • this week stop of scanning activity for software upgrade (chrysalis • version) • tuning of scanning parameters for HF bricks in progress • Hardware: • 1 plate changer installed and working on 1 microscope, tests with DB • planned after software upgrade completion.

  21. Conclusions Scanning of Run 2008 bricks in progress Located neutrino events up to now: 58 (49 CC + 9 NC) • Planned: • momentum measurement of all tracks of located neutrino events with • low energy muons • decay search for the whole sample of our neutrino events

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