1. Reconstruction of neutrino interactions in PEANUT in general scanning (unbiased) mode Giovanni De Lellis on behalf of Andrea Russo Naples University

2. PEANUT detector BL033 Neutrino beam and Cosmic ray exposure BeamPositionStartEndDuration (day) NEUTRINO1412005/10/20 16:252005/11/07 09:2017.75 COSMIC RAYS2005/11/07 09:402005/11/07 11:400.08 (2h)

3. Scanning areas All 57 plates have been general scanned: 5.55 x 4.30 cm^2 = 23.9cm^2 General scanning mode Measured density of aligned base-tracks: 4 base-track / mm 2 (transportation order) 0.7 base-track / mm 2 (assembly order) 38 plates have been general scanned: 11.1 x 4.30 cm^2 = 47.8 cm^2

4. PEANUT emulsions Transportation order Beam exposure

5. s ~ 8 m m Track reconstruction s =13 mrad Micro-track angular resolution Position and angular resolution in the plate to plate alignment Consecutive base-track accuracy s ~ 5 mrad

6. s = 0.7 m m s = 3mrad Base-track resolution: spatial and angular difference between a base-track and the corresponding volume track

7. Density of aligned base-tracks ~ 4/ mm 2 Track reconstruction in transportation order

8. Characterization of the tracks in transportation order Due to low momentum protons (~100MeV) High ionizing power (at least 10 segments in the following plots) High tracking efficiency

9. Beam tracks at least 4 segments in the plots shown NuMI beam peak (  x,  y ) ~ (-50,0) mrad MIP particles: ~ 24 Tracking efficiency Density of aligned base-tracks ~ 0.7 / mm 2

10. Emulsion-SFT matching yx txty  x = 1190  m  y = 1240  m  tx = 5 mrad  ty = 8 mrad Angular misalignment

11. Brick rotation beam   = 24 mrad  2.4 mm SFT planes brick  z depending on the position zz Top View

12. Emulsion-SFT matching after  z correction  x = 605  m  y = 443  m  tx = 6 mrad  ty = 5 mrad

13. Impact parameter and  z distribution track to vertex longitudinal distance IP zz ~ 60% up to 10 µm

14. Neutrino event identification 62278 volume tracks reconstructed 2995 vertices reconstructed 658 with all forward tracks 17 confirmed by SFT (154 “  z versus IP” ) 7 pass the “  z versus IP” cut 11765 made of more than 4 base-tracks 171 confirmed by SFT 17 with UP > 3 Identification of 24 neutrino interactions in the fiducial volume Single track eventsMultiple track events MC Multiplicity

15. “High” multiplicity events not matching the SFT dz (  m)ip (  m) 6971.2 6970.4 19888.2 dz (  m)ip (  m) 9122.4 22030.8 9122.3 dz (  m)ip (  m) 9413.4 222610.0 9413.9 tx (mrad)ty (mrad) -26244 156-126 -99379 tx (mrad)ty (mrad) 394-231 -642-2 355-402 tx (mrad)ty (mrad) -381-380 116-131 -43-716

16. “High” multiplicity events not matching the SFT dz (  m)ip (  m) 204118.1 204120.1 204122.1 dz (  m)ip (  m) 13182.9 13184.2 13184.9 tx (mrad)ty (mrad) 67231 66-116 -13451 tx (mrad)ty (mrad) -3988 -101129 -4493

17. “High” multiplicity events not matching the SFT tx (mrad)ty (mrad) 23432 84-169 269-316 -131198 Dz (  m)ip (  m) 10406.0 10404.1 10405.5 235843.3 dz (  m)ip (  m) 5820.3 5820.7 5821.0 tx (mrad)ty (mrad) 90-257 -1441 82229

18. “High” multiplicity events not matching the SFT tx(mrad)ty(mrad) 23-191 -48148 264-121 193188 -33134 -20472 -180-303 2-388 16242 dz(  m)ip(  m) 169910.3 169910.9 16998.1 16995.0 16995.1 16993.9 16996.6 169923.0 169915.4 Preliminary Multiplicity 9!

19. Expected number of events in the brick BeamBeginEndDuration (days) NEUTRINO2005/10/20 16:252005/11/07 09:2017.75 COSMIC2005/11/07 09:402005/11/07 11:400.08 Neutrino interaction rate in an iron target exposed to NuMI in the near hall (2 * 10 5 ) / (year * ton) 43 ± 7 neutrino interactions expected in the analyzed volume N mes /  total = 44 ± 9 neutrino interactions estimated from the 24 observed events after efficiency correction This value (increased by 8%) accounts for the lead target

20. Conclusions A volume of 413 cm 3 (58% of the brick volume) was general scanned in one PEANUT brick Detailed single brick Monte Carlo simulation of PEANUT used to define a procedure to identify neutrino interactions 24 neutrino interactions with SFT matching have been identified in the volume After the efficiency correction, we estimate (44 ± 9) neutrino interactions happening in the volume Good agreement with the number of expected events (43 ± 7) computed from the flux 8 events with larger multiplicity found without any match with the SFT (6 with 3 tracks, 1 with 4 and 1 with 9 tracks)