1. Event Location Rehearsal in PEANUT Bricks OPERA collaboration meeting Gran Sasso, May 2006 Kodama, Sato, Fukuda, Komatsu, Narita, Nonoyama NAGOYA

2. We started event location rehearsal in March 2006 using PEANUT bricks. First report has been presented at Project Board on 24 th March 2006 at GS. –4 rock muon events and 1 neutrino interaction candidate –It took about 30min/event for scan back Current status of this rehearsal is presented here.

3. Key feature PEANUT brick Real OPERA brick –Film : Real OPERA film Tono refreshed (BL118: 170613-04D01) same process batch films are shipped to GS in boxes NAGOYA+05098,05104,05106… –Lead plate: OPERA lead plate (PbSb) X-ray mark –Plate to plate alignment CS emulation by Scintillation fiber tracker –Most downstream doublet film + SFT = CS We can tag single track for location test

4. PEANUT BL118 history @Fermilab –Brick assemble : Nov./25/2005 –Beam exposure : Nov./25/2005-Feb./28/2006 –X-ray marking : Mar./15/2006 –De-packing : Mar./16/2006 @Nagoya –Arrival from Fermilab : Mar./20/2006 –Develop : Mar./20/2006 –Doublet film scan : Mar./21 (20hour by S-UTS) –CS emulation by SFT matching : Mar./22 –Track follow trial : Mar./22 –Location trial : Mar./23

5. X-ray Generator X-ray mark exposure bench OPERA Proto-type 1m Exposure time : 5 sec Angle : 4.8 degree Slit: Kim, System: Zama

6. X-ray exposure @ Fermilab We brought X-ray exposure bench to Fermilab X-ray generator X-ray slit 50  m wide PEANUT brick X-ray slit

7. Scanning using X-ray X-ray Brick Intersection of two planes (X-ray) defines a reference line in the Brick. Reference Point X-ray

8. CS emulation (SFT matching) S-UTS scanning –tan(  )<0.15, 100cm 2 x 2 film = 20hour –1187 matched tracks tagged in 2mm, 40mrad mm rad

9. CS Emulation Data Taking General Scan on plates 01 and 02 to pickup tracks matching to SFT. Scanning Status –UTS scan is to recover limited angular acceptance of current S-UTS BrickS-UTS scan  <0.15rad UTS scan  <0.40rad BL118DoneReady soon BF021DoneNot yet BL112DoneNot yet All PEANUT bricks in Nagoya with X-ray mark printed.

10. Rock Muons Scanned –BL11842 tracks –BF02114 tracks Mean UTS efficiency –0.70 with x40 dry objective lens –PH  8 Scanning Time –20 ~ 40 min/track Rock Muon Scan Back All of them penetrated Angle difference between pl.03 and SFT rms ~ 7mrad

11. To calculate a predicted position, relative position between emulsion plates were obtained by Xray marks ONLY Alignment by Xray for ScanBack Accurate enough 1view of x40 dry objective Found position - Predicted Neutrino beam

12. Scanning Time for Rock Muons Rehearsal begins on 22-Mar 01-Apr 01-May Events/day We have to run at 30events/day # of plates scanned scanning time (min)

13. Event Selection for Rehearsal Multi track vertex Veto Kink

14. Multi Track Vertex

15. Veto

16. Kink

17. Scan Back Result EventSelection category SFT matching at pl01-02SFT Matching at pl03 Scan Back Result Note dxdydtxdtydtxdty BL118-0082Multi-359.8-220.90.0034-0.0151-0.00780.0050Penetrated BL118-0092Multi28.0425.2-0.0054-0.01030.01250.0035Stop at pl45Neutrino Int. Cand. BL118-0344Multi-30.6-1409.80.01660.02950.0209-0.0194Penetrated BL118-0784Multi-1910.0364.7-0.01040.0050-0.02570.0182Penetrated BL118-1105Multi-285.2-195.90.0068-0.0015-0.01240.0129Stop at pl37Neutrino Int. Cand. BF021-0084Multi-529.61548.1-0.0198-0.0025-0.00400.0300Penetrated BF021-0093Kink320.41428.3-0.0028-0.0239-0.0144-0.0052PenetratedKink BF021-0138Kink206.5884.1-0.00060.00260.00180.0021PenetratedKink BF021-0283Multi166.1-71.5-0.0122-0.0116-0.00800.0120Penetrated BF021-0490Multi-725.3-23.0-0.0122-0.0003-0.01100.0100Penetrated Measured at pl02

18. Event BL118-1105

19. Located Neutrino Interaction in BL118 Event 1105 Scan Back Track Tx = -0.127 Ty = -0.097 Tx = 0.038 Ty = 0.040 Neutrino beam These tracks have IP=1.7micron at 199micron upstream from up surface of plate 37 No track in up stream plate pl.37 pl.38

20. Event BL118-0092

21. Scan Back Track T0 ( -0.0336, 0.0345 ) → stopped at pl.45 Vertex confirmation: Try to find partner track manually, which was seen in SFT, assuming a vertex in an lead plate upstream of pl.45. 2 candidate tracks ( T1 and T2 ) were found. –Both are almost parallel and about 5micron apart. –T1 angle = ( -0.447, -0.506 ), min. distance to T0=6micron at dz=231micron –T2 angle = ( -0.367, -0.393 ), min. distance to T0=2micron at dz=289micron Both T1 and T2 were not found in upstream plate ( pl.46 ). In downstream plate ( pl.44 ), T2 was found, but T1 was not found. Follow down T2 was followed down to pl.02 T2 angle at pl.02 is ( -0.413, -0.444 ) and SFT is ( -0.408, -0.449 ) Good match. T1 might be low momentum pion and T2 is probably a proton. dE/dx……. Event BL118-0092

22. pl01 Stopped at pl45 neutrino Scan Backed Track T0 Partner Track T2

23. Event BF021-0138

24. pl01 pl57neutrino (Tx,Ty) = (-0.0561,-0.0687) in emulsion ( pl02 ), (-0.0543,-0.0666) in SFT (Tx,Ty) = (-0.1782,-0.0695) in emulsion ( pl57 ), (-0.1587,-0.0666) in SFT NOTE : 1 ion plate exists upstream of pl57

25. pβ= 733±97 MeV/c Event BL021-0138 Momentum estimation Tscat 2 = ( DT of THE track ) 2 – ( DT of a rock muon ) 2 DT of THE track Every 2 plates DT of a rock muon Every 2 plates 意味が無いかもしれませんが、 Rock muon の運動量が十分高いと仮定しての運動量推定です。

26. Event BF021-0093

27. pl01 pl57 neutrino (Tx,Ty) = (-0.0690,-0.1500) in emulsion ( pl02 ), (-0.0546,-0.1448) in SFT (Tx,Ty) = (-0.1300,-0.1390) in emulsion ( pl57 ), (-0.1179,-0.1706) in SFT NOTE : 1 ion plate exists upstream of pl57

28. Scan Back Result ( continued ) EventSelection category SFT matching at pl01-02SFT Matching at pl03 Scan Back Result Note dxdydtxdtydtxdty BL112-0224 BL112-0271 Multi-168.8 -1169.6 1398.3 -380.3 0.0284 -0.0234 0.0056 0.0077 -0.0256 0.0000 0.0157 0.0006 Penetrated same event BL112-0486Multi-298.1-156.60.00880.0001-0.01130.0191Penetrated BL112-0635Multi-370.0-816.40.00140.0039-0.01470.0113Stop at pl43Neutrino Int. Cand. BL112-0700Multi-652.1573.90.01340.0084-0.00190.0172Penetrated

29. Event BL112-0635

30. Scan Back Track (T0) Tx = 0.138 (SFT) Ty = 0.039 (SFT) Partner Track (T2) Tx = 0.019 Ty = -0.079 Neutrino beam These 4 tracks have IP=0.8 micron at 138 micron upstream from up surface of plate 43 pl.43 Event BL112-0635  Partner Track (T1) Tx = 0.206 Ty = -0.053 (SFT) Partner Track (T3) Tx = 0.039 (SFT) Ty = 0.002 (SFT)

31. Summary PEANUT Analysis ： Realistic exercise for OPERA event Location, Scan back, Vertex confirmation and Follow down with real neutrino events. Really OPERA rehearsal. System R&D, Human exercise etc are going on……………….. X-ray mark alignment works perfectly Currently, it took 30 minutes for track follow from bottom to top. –In this time, manual checks were applied to all of the scanned point. –We are sure, we can achieve 10 minutes for track follow. We are CONFIDENT to carry out location for 30event per day with only one system. –Vertex analysis after location will be done by other UTS system. Up to now, 4 bricks ( Cosmic, BL118, BF021, BL112 ) have been made to TAPE and 3 of them have been scanned. Systematic Vertex confirmation study will be started for stopped events.