Status report of the PEANUT analysis Giovanni De

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Status report of the PEANUT analysis Giovanni De Lellis Collaboration Meeting, June 5 th

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

Analysis schema • Two analysis streams – SFT driven scan-back, i. e. 2 most

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 2

General scanning: a procedure to identify multi-track neutrino events optimized with the MC simulation

General scanning: a procedure to identify multi-track neutrino events optimized with the MC simulation IP 90 (mm ) • 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 identify single-track events • At least 5 base-tracks • The track with UP > 3 and DOWN < 4 • Track confirmed by SFT detectors 3 For example: UP=4 and DOWN = 2

Neutrino event identification Single track events • 12563 made of more than 4 base-tracks

Neutrino event identification Single track events • 12563 made of more than 4 base-tracks Multiple track events • 4606 vertices reconstructed • 252 confirmed by SFT • 24 with all tracks forward and confirmed by SFT • 23 with UP > 3 • 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 Nu. MI 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 4

dz mm ip (mm) tx mrad ty mrad 335 0. 9 -76 130 335

dz mm ip (mm) tx mrad ty mrad 335 0. 9 -76 130 335 0. 3 -67 16 335 0. 9 -48 77 1635 12. 2 -143 216 1635 5. 4 -115 300 1635 6. 4 8 173 1635 5. 5 -13 150 1635 9. 4 -123 171 1635 6. 1 -60 184 2947 19. 3 -70 80 2947 14. 5 -148 228 2947 25. 6 -129 180 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 5

Unbiased analysis in Bologna • After fine alignment, tracks are searched for in the

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 PL 1 or PL 2: 13290 volume tracks • Alignment between emulsion and SFT (3667 SFT tracks) performed with longitudinal offset correction 1341 matches • Brick with 12 h cosmic-ray exposure (background rejection under evaluation) Multi-prong sample 29 VTX 8 created Inside 20 Passing 1 Upstream 1° wall Single-prong sample 291 56 Created Inside 221 Passing-Through 14 Upstream of 1 st wall 6 UP>3 28 out of 56 events

Scan-back in Bern (SFT predictions from DB) Current Status: BL 090: General Scanning of

Scan-back in Bern (SFT predictions from DB) Current Status: BL 090: 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) BL 092: General Scanning of Plates 1 and 2 7

“Virtual” scan-back in Bologna • SFT selected from DB, match procedure: • 607 SFT-PL

“Virtual” scan-back in Bologna • SFT selected from DB, match procedure: • 607 SFT-PL 1 -PL 2 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 downstream area: 5 x 5 mm 2 • Stopping point in the range 6<PL<53 331 tracks selected • Events by SFT classification: Total Scan SFT Class Passing Created Inside Upstream Total passing 33 16 5 54 Not. Rec 33 17 5 55 Stop 1 -prong 138 49 15 202 Stop Multi-prong 5 3 3 11 Stop out Vol. 8 1 0 9 331 8

3 -prong VTX with SFT matching 9

3 -prong VTX with SFT matching 9

Scan-back at LNGS ~ 8 mm ~ 4. 6 mm ~ 2. 4 mrad

Scan-back at LNGS ~ 8 mm ~ 4. 6 mm ~ 2. 4 mrad ~ 5 mrad scan-back predictions: pass-through tracks (maxplate >= 35) stopping points 217 134 83 -------> 10 only 6/83 confirmed manually 8 (up to plate 37)

Scan-Back in Neuchatel 263 SFT matching tracks followed in the brick 120 Stopping Points

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

Total-Scan analysis in Salerno (BL 081 and BL 082) Outcome of Scan-back + Manual

Total-Scan analysis in Salerno (BL 081 and BL 082) Outcome of Scan-back + Manual checks Brick Scanback paths Stop Pass Scatter Vacuum channel Edge. Out BL 081 297 45 21 10 5 8 1 BL 082 383 82 29 40 0 7 4 Efficiency problems on many plates Unbiased Total-Scan to check both Scan-back and Manual checks: data collected around all stopping points in 5× 5 mm 2×(5+5 plates) 5+5 plates = 4+4 plates for reconstruction + 1+1 plates for Virtual erasing Preliminary reconstructions available (using 10 plates) Run 47 Event 189037 – stop at plate 12 V 4 event in the emulsion 6 SFT tracks reconstructed No match from non-scan-back tracks Skewed view Red: Scan-back Iris: Total-Scan 12

Total. Scan samples from BL 081 “Scattering event” Run 47 Event 89037 – stop

Total. Scan samples from BL 081 “Scattering event” Run 47 Event 89037 – stop at plate 14 Prongs Event Count 1 10 2 2 3 1 4 1 Total 14 Type Event Count SB stop TS scatter 5 SB stop Fail. align. (bad data quality near vacuum channel) 2 Skewed view Red: Scan-back Iris: Total-Scan Manual Check pass TS 7 stop Total SFT: 0. 073, -0. 094, nhits = 12 SB start/stop: 0. 106, -0. 084 / 0. 124, -0. 088 13 U TS + AWRec: 0. 098, -0. 079 D/ 0. 075, -0. 092 Scattering classification possibly due to local slope tilting 14

Scan-back and total scan in Naples 273 predictions selected by a 3 cut in

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 mm 2 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

Neutrino interaction occurred 10 mm inside the lead plate Manual check information in the

Neutrino interaction occurred 10 mm inside the lead plate Manual check information in the transverse plane 1 8 MIP 4 nuclear fragments 8 2 3 6 7 4 5 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

Analysis of the 8 stopping points (stopping also according to the SFT) 1 vertex

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 67 new stopping points have been identified 45 out of 67 are passing through SFT 3 D track 22 out of 67 are stopping SFT 3 D tracks

Scanning status at Nagoya Cosmic-Ray (tanq<=0. 4) • Brick Assembly • 13 m(horizontal)0. 19

Scanning status at Nagoya Cosmic-Ray (tanq<=0. 4) • Brick Assembly • 13 m(horizontal)0. 19 x 13 x 100 = 247 • 1 h 30 m(vertical)0. 013 x 90 x 100 = 117 • De-pack Total Scanning Area (cm 2) • ~20 m(horizontal)0. 19 x 20 x 100 = 380 • max~5 h(vertical)0. 013 x 300 x 100 = 390 • Under Ground(-105 m) • 97. 39 day x ( surface x ~1/100 ) Start : 2006 12/23 * Flux Measurement @Flab with emulsion vertical - 0. 013 /min/cm 2 horizontal - 0. 19 /min/cm 2 One brick completed 10000 cm2 / 1 month = 1 m 2 / 1 month date 17

Shower search candidate in Nagoya 18

Shower search candidate in Nagoya 18

Nu-e int candidate 1 ry VTX 1 ry electron candidate pi 0 shower 19

Nu-e int candidate 1 ry VTX 1 ry electron candidate pi 0 shower 19

Brick configuration and schedule for the Run 2 • Target region : 61 of

Brick configuration and schedule for the Run 2 • Target region : 61 of 500 micron SUS 304. • Radiator region: 15 1 mm lead. Film +film+ (Fe + film)*61 + (Pb + film)*15 0. 5*61 + 1. 0*15 + 0. 288*93 = 72. 25 mm Radiation length = 1. 79+2. 68 = 4. 47 X 0 5. 09 kg (2. 97 kg+2. 12 kg) 9. 9 K+7. 0 K int. expected for 48 bricks 100 days • Shutdown foreseen on Aug 6 th 60 days exposure 10 K events • Two weeks for run setup – Start setup at Fermilab on May 31 st (2 European and 4 Japanese) • Darkroom setup at MINOS Service Building – Brick assembling • Started the day before yesterday • Nu. MI shutdown on Aug 6 th 20 – move after this shutdown for MINERv. A or LAr setting up.

Summary of the ongoing analysis • 22 bricks under analysis in Europe • Nagoya

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 scan performed 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) • Monte. Carlo simulation improved with SFT hit simulation • Multiplicity study and measurement of 3 components (DIS, QE and RES) feasible with RUN 1 21 • Electron neutrino component in RUN 2