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Status report of the PEANUT analysis

Status report of the PEANUT analysis. Giovanni De Lellis. Collaboration Meeting, June 5th 2007, Maiori. Analysis schema. Two analysis streams SFT driven scan-back, i.e. 2 most downstream films are aligned and the coincidence is matched with the SFT, only matched tracks are followed up

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Status report of the PEANUT analysis

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  1. Status report of the PEANUT analysis Giovanni De Lellis Collaboration Meeting, June 5th 2007, Maiori

  2. Analysis schema • Two analysis streams • SFT driven scan-back, i.e. 2 most downstream films are aligned and the coincidence is matched with the SFT, only matched tracks are followed up • General scanning on a full (large) surface of all films, reconstruct the vertices and match the SFT at the end • Standardized analysis to get physics results, from SFT predictions to the analysis cuts

  3. IP90 (mm) General scanning: a procedure to identify multi-track neutrino events optimized with the MC simulation • Topological cuts on reconstructed vertices: Impact Parameter, IP < 50 µm and track-vertex longitudinal distance, z < 3000 µm • All tracks downstream of the vertex • At least one track confirmed by SFT detector • z-versus-IP bi-dimensional cut as in previous slide A procedure to identifysingle-track events • At least 5 base-tracks • The track with UP > 3 • and DOWN < 4 • Track confirmed by SFT detectors For example: UP=4 and DOWN = 2

  4. Neutrino event identification Single track events Multiple track events • 12563 made of more than 4 base-tracks • 252 confirmed by SFT • 23 with UP > 3 • 4606 vertices reconstructed • 24 with all tracks forward and confirmed by SFT • 7 pass the “z versus IP” cut Identification of 30 neutrino interactions in the fiducial volume Neutrino interaction rate in an iron target exposed to NuMI in the near hall (2 * 105) / (year * ton) This value (increased by 8%) accounts for the lead target 54 ± 7 neutrino interactions expected in the analyzed volume Nmes/etotal = 56 ± 10 neutrino interactions estimated from the

  5. 12 tracks (8 primary) • 9 vertices with multiplicity 3 • 1 vertex with multiplicity 9 • 1 vertex with multiplicity 12 Electron pairs Open angle for 2 track vertices Electron pair signal

  6. Unbiased analysis in Bologna • After fine alignment, tracks are searched for in the volume to recover the broken tracks at the boundaries of the smaller volumes • Total number of reconstructed volume tracks: 78088 • Tracks with nseg>3 and one base-track on PL1 or PL2: 13290 volume tracks • Alignment between emulsion and SFT (3667 SFT tracks) performed with longitudinal offset correction  1341 matches • Brick with 12h cosmic-ray exposure (background rejection under evaluation) Multi-prong sample Single-prong sample 8 created Inside 20 Passing 1 Upstream 1° wall 56 Created Inside 221 Passing-Through 14 Upstream of 1st wall 29 VTX 291 UP>3  28 out of 56 events

  7. Scan-back in Bern (SFT predictions from DB) Current Status: BL090: General Scanning of Plates 1 and 2 Match with SFT -> 306 matches found Scan Back -> 94 stopping points 2<emulsion plate<56 Total Scan (ongoing) BL092: General Scanning of Plates 1 and 2

  8. “Virtual” scan-back in Bologna • SFT selected from DB, match procedure: • 607 SFT-PL1-PL2 matched tracks • Scan-back is performed and 420 stopping points are identified (too large background) • Total-scan performed around 420 stopping points+5 plates upstream-5 plates downstreamarea: 5x5 mm2 • Stopping point in the range 6<PL<53  331 tracks selected • Events by SFT classification: SFT Class Total Scan

  9. 3-prong VTX with SFT matching

  10. Scan-back at LNGS • ~ 8 mm • ~ 4.6 mm • ~ 2.4 mrad • ~ 5 mrad scan-back predictions: 217 pass-through tracks 134 (maxplate >= 35) stopping points 83 -------> only 6/83 confirmed manually (up to plate 37) 8

  11. Scan-Back in Neuchatel 120 Stopping Points Total scan 5 plates upstream & 3 downstream New ScanBack 6 Fake Stops 8 Confirm Stops 1 Two prong 105 Not found 263 SFT matching tracks followed in the brick

  12. Total-Scan analysis in Salerno (BL081 and BL082) Outcome of Scan-back + Manual checks Efficiency problems on many plates Unbiased Total-Scan to check both Scan-back and Manual checks:data collected around all stopping points in 5×5mm2×(5+5 plates) 5+5 plates = 4+4 plates for reconstruction + 1+1 plates for Virtual erasing Preliminary reconstructions available (using 10 plates) Skewed view Red: Scan-backIris: Total-Scan Run 47 Event 189037 – stop at plate 12 V4 event in the emulsion 6 SFT tracks reconstructed No match from non-scan-back tracks

  13. TotalScan samples from BL081 “Scattering event” Run 47 Event 89037 – stop at plate 14 Skewed view Red: Scan-backIris: Total-Scan SFT: 0.073, -0.094, nhits = 12 SB start/stop: 0.106, -0.084 / 0.124, -0.088 TS + AWRec: 0.098, -0.079 D/ 0.075, -0.092 U Scattering classification possibly due to local slope tilting

  14. Scan-back and total scan in Naples 273 predictions selected by a 3 cut in position and angle w.r.t SFT: 198 passing through and 75 stopping (no hit upstream) Total scan performed for the first 22 stopping points 5*5 mm2 area * 8 films (3 upstream of the stopping point, 4 downstream) • 14 passing through SFT tracks • 8 stopping SFT tracks Stop Confirmed • 1 multi-prong vertex confirmed in the passing through SFT sample

  15. 1 8 2 3 5 4 6 7 Manual check information in the transverse plane Neutrino interaction occurred 10mm inside the lead plate 8 MIP 4 nuclear fragments Track angles 1: 0.078 0.480 2: 0.089 -0.040 3: 0.146 -0.241 4: 0.260 -0.150 5: 0.423 -0.249 6: -0.360 -0.470 7: -0.045 -0.360 8: -0.017 -0.083

  16. Analysis of the 8 stopping points (stopping also according to the SFT) 1 vertex (multiplicity 2) found All of them (8) confirmed in total scan analysis • 5 vertices with multiplicity 1 • 3 vertices with multiplicity 2 67newstoppingpoints have been identified 45 out of 67 are passing through SFT 3D track 22 out of 67 are stopping SFT 3D tracks

  17. Cosmic-Ray (tanq<=0.4) • Brick Assembly • 13m(horizontal)0.19x13x100 = 247 • 1h30m(vertical)0.013x90x100 = 117 • De-pack • ~20m(horizontal)0.19x20x100 = 380 • max~5h(vertical)0.013x300x100 = 390 • Under Ground(-105m) • 97.39day x ( surface x ~1/100 ) • * Flux Measurement @Flab with emulsion • vertical - 0.013 /min/cm2 • horizontal - 0.19 /min/cm2 Scanning status at Nagoya One brick completed Total Scanning Area (cm2) 10000cm２ ／ １ month = 1m2／ 1 month date Start : 2006 12/23

  18. Shower search candidate in Nagoya

  19. Nu-e int candidate 1ry VTX 1ry electron candidate pi0 shower

  20. Brick configuration and schedule for the Run2 • Target region : 61 of 500 micron SUS304. • Radiator region: 15 1mm lead. Film +film+ (Fe + film)*61 + (Pb + film + film)*15 0.5*61 + 1.0*15 + 0.288*93 = 72.25mm Radiation length = 1.79+2.68 = 4.47 X0 5.09kg (2.97kg+2.12kg) 9.9K+7.0K  int. expected for 48 bricks 100days • Shutdown foreseen on Aug 6th  60days exposure  10K events • Two weeks for run setup • Start setup at Fermilab on May 31st (2 European and 4 Japanese) • Darkroom setup at MINOS Service Building • Brick assembling • Started the day before yesterday • NuMI shutdown on Aug 6th • move after this shutdown for MINERvA or LAr setting up .

  21. Summary of the ongoing analysis • 22 bricks under analysis in Europe • Nagoya is focused on general scanning (1 brick analysis ongoing) • General scanning: Naples (30 located events), Bari (10 2-track VTX) and Bologna (8+28)  ~ 200 events (the SFT bias removable and useful to cross-check the scan-back) request to provide a summary of the data analyzed (multiplicity and SFT matching) • Scan-back and total scanperformed in a few labs and the confirmed stopping points are: Salerno (50), Naples (25) a few hundred located events expected within Summer • Large effort in the optimization of the strategy and tuning of parameters • Non-linear extrapolation to the expected events • The connection between PEANUT and MINOS to be provided (US) • MonteCarlo simulation improved with SFT hit simulation • Multiplicity study and measurement of 3 components (DIS, QE and RES) feasible with RUN1 • Electron neutrino component in RUN2

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