Film Storage and book-keeping Scanning Quality Control Cosmic Ray Density Vertex Confirmation Vertex Location WG4 summary

Film Storage and book-keeping –First version ‘Brick Tracer’ ready to use ( C. Bozza ) Scanning Quality Control –SUTS ( K. Morishima ) –ESS ( C. Bozza ) WG4 summary

Cristiano Bozza – European Emulsion Scanning Group – Nagoya Jan Brick tracer

Cosmic Ray Density –Aim of cosmic ray exposure is to provide alignment for momentum measurement and decay search. –Data shows we can go down to ~1/5 while keeping alignment accuracy. ( A. Ariga ) –Brick deformation can be corrected using Cosmic Rays during transportation ( S. Takahashi ) now ~6micron rms whole OPERA film WITHOUT cosmic rays Further improvement is being studied. One can apply this method for Bricks with black CS to have have NO cosmic ray exposure. For normal bricks we can use cosmic rays in larger area for alignment. This method requires a brick should be made of emulsion sheets in a single pack. WG4 summary

1.4cm x 1.4cm x 11plates 369 tracks in scanning area dx  (dx) = sqrt(3/2)*  (x)‏  From the point of alignment. Higher cosmic density doesn't give higher resolution. 1/3~1/5 of current exposure is enough to get same alignment accuracy(1micron).

Cosmic Ray Density –Aim of cosmic ray exposure is to provide alignment for momentum measurement and decay search. –Data shows we can go down to ~1/5 while keeping alignment accuracy. ( A. Ariga ) –Brick deformation can be corrected using Cosmic Rays during transportation ( S. Takahashi ) now ~6micron rms whole OPERA film WITHOUT cosmic rays Further improvement is being studied. One can apply this method for Bricks with black CS to have have NO cosmic ray exposure. For normal bricks we can use cosmic rays in larger area for alignment. This method requires a brick should be made of emulsion sheets in a single pack. WG4 summary

Deformation map between film micron

Deformation map between film 1 – 50micron

RMSy=1.4micron RMSx=2.4micron difference (transportation - brick) (film 1 – 2) 10micron Deformation seems conserving between transportation and brick.

Virtual alignment ･ Used several films of brick:36565 exposed CR ･ Scanned full area ･ Important to read X-ray mark accurately for accurate alignment –Trying now ･ Instead of X-ray mark, used tracks at area near the X-ray mark ･ Global correction is used tracks at area near the X-ray mark. ･ Local correction is used tracks at transportation ･ After virtual alignment, I check position difference using brick tracks. X-ray mark x y 1cm Lead d film

Position difference offset[micron] = ( -13.2, 2.2 ) RMS[micron] = ( 5.8, 5.8 ) Position difference have offset. [micron] dxdy plate

Prospect for offset If films curl at transportation offset appear. CR transportation after scanning If curl effect contribute offset should be had same value.

Offset for several combinations film1 – film2 offset dx[micron] offset dy[micron] 25 – – ｰ Offset is same within several micron.

Worries about “reducing cosmic ray density” exists … but –Some scan back using X-ray marks were tried also in Europe side. Lyon ( L. Arrabito ) –Cross check can be done soon using brick data taken so far. WG4 summary

Vertex Confirmation –Volume scan procedure using SUTS ( T. Fukuda ) –Summary of events Nagoya ( U. Kose, N. Kitagawa ) Bern ( C. Pistillo ) Lyon ( L. Arrabito ) Vertex Location –NO cosmics for bricks with Black CS Presentations in A. Ariga and S. Takahashi -> Alignment w/o cosmics –Bern NC event ( I. Kreslo ) One vertex related to cosmic rays One vertex outside a brick No CSD tracks TT match No Veto tracks Shift management and human organization –Homework for each lab WG4 summary

ECC with black CS (current Nagoya strategy.)‏ 1.General scan the downstream plates(3~5). 2.search vertex candidates. 3.Scanback or Direct vertexing. Strong worry about the 2 nd, 3 rd, vertex by cosmic ray. --> no cosmic on the ECC with black CS. Next talker, Takahashi. ECC downstream

NC event

Volume scan around vertex Tracks are visible in veto => This is NOT a neutrino event, but HE cosmics reaction

After scanback of ~1300 tracks two interesting vertices found