Status of automatic scanning and vertex recognition at Toho Univ. September 27, Gyeongsang National University H. Shibuya, S. Ogawa, S. Fukunaga, T. Fukuda, T. Matsuo Toho University 1.Emulsion Scanning System at Toho University 2. Study of lambda hypernuclei (KEK E373 & J-PARC E07) Status of automatic scanning and vertex recognition

1 1. Scanning system of our laboratory Automatic scanning system 1) Nikon L-Mic equipped with Ultra Track Selector (UTS) 2) Nikon L-Mic equipped with SONY XC-HR300 system 7 and LED lighting system (Uniopt)  Auto Stage II 3) Nikon L-Mic equipped with MIKROTRON EoSens MC1362 (and LED lighting system (Uniopt), FTS) system 11 Semi-automatic scanning system 4) Nikon-L-Mic equipped with C3077 system 10 controlled by WinRT  Auto Stage I 5) Mitaka 17cm*17cm controlled by DOMS 6) Mitaka 40cm*50cm controlled by DOMS system 9

2 FTS to detect large angle tracks system 11 FTS T. Fukuda et al., JINST 8 (2013) P01023 Detection efficiency of MIP base tracks vs. tan  Microscope view of a filmCross-sectional view of a film Automatic scanning of emulsions with wide-angle acceptance Track recognition algorithm Efficiency> 90%

2. Status of automatic scanning and vertex recognition at Toho Univ. 3 Present activity for hypernucleus studies at Toho University Automatic general/overall scanning is being performed in order to detect hypernuclei in KEK E373 emulsion plates. Procedure to search for hypernucleus events ① Emulsion plates of E373 are scanned by an automatic general/overall scanning system. ② Images which have at least one vertex are extracted by an image processing program. ③ Images which have two vertices are selected in extracted images by visual inspection ④ Real emulsion plates are placed on a microscope stage and checked in order to confirm whether there are two vertices by visual inspection. by S. Fukunaga (M2)

2. Status of automatic scanning and vertex recognition at Toho Univ. 4 XC-HR300(sony) Frame rate100Hz Camera for System7 Specification OS Windows2000 professional CPU1.70GHz Memory256MB PC for System7 Specification system 10 system 7

5 ① Outline of automatic general/overall scanning emulsion X-Y plane Y x 1 Set Scan Save emulsion Z x base 120 μm X-Z plane 250 μm ・ The microscope stage is moving continuously not only along the z direction but also along the x direction ・ Tomographic image data are taken while the camera goes down and they are saved while the camera goes up. ・ 84 image data are acquired in 1 set. 330 mm Overlap:20 μm ・ The number of fields of view (1 view:0.12×0.1mm 2 ) X:3300 Y ： 4100 ・ Size of emulsion plates ・ E07 ： 350×350mm 2 ・ E373:250×245mm 2 Total ：

6 ② Analysis of acquired images 1. Resolution reduction 2. Increase the contrast 3.Homogenizaton of background by Gaussian Filter 4.Filterring 5.binarization 6.Noise elimination 7.thinning 8.Hough transformation 9.Detection of vertex 2. Detect vertex Tomographic mages are acquired by the automatic general scanning. images which have a vertex are extracted by an image processing program. 5 layers 1. Superimpose 5 tomographic images

7 Analysis procedure and event classification Extracted images Images which have two vertices Other images Interesting events Check images Check emulsion ③ ④

8 Automatic scanning and checking images ・ module#87, plate#: 6, 7 ・ module#88, plate#: 6, 7 ・ module#89, plate#: 6, 7 ・ module#84, plate#: 6, 7 ・ module#83, plate#: 6, 7 ・ module#38, plate#: 6, 7 ・ module#85, plate#: 6, 7 ・ module#35, plate#: 6, 7 ・ module#41, plate#: 6, 7 ・ module#44, plate#: 6, 7 We scanned an area of 15 × 15 mm 2 at the center part in each emulsion plate. So far 16 emulsion plates have been scanned and analyzed. Green: all the processes have been completed including checking emulsion plates. Red: scanning has been finished but checking images has not been finished yet.

9 Number of images extracted by image processing

10 Number of events checked in emulsion plates

11 Ratio = number of events checked in emulsion/ number of images extracted by image processing

12 Status of scanning and analysis ・ Total volume of emulsion where events with a second. vertex were searched for : 1.5 cm×1.5 cm×0.025 cm ×16 plates = 0.9 cm 3 ・ Number of images extracted by image processing: ・ Number of events checked in emulsion: 299 ・ Number of events associated with a second. vertex : 42 Classification ・ Beam interaction ： 27 ・ hammer track: 4 ・ Absorption of a Xi particle: 10 ・ Other （ it looks like a beam interaction but no incident beam ） : 1

13 Interesting events (beam interactions)

14 Interesting events (beam interactions)

15

16 Interesting events (beam interactions)

17 Interesting events (beam interactions)

18 Interesting events (hammer track)

19 Interesting events (absorption of a Xi particle)

20 Interesting events (absorption of a Xi particle)

21 Summary 1)We have 3 scanning systems, each has a different feature. ・ L-Mic stage with C3077, WinRT (Auto stage I) system 10 ・ L-Mic stage with XC-HR300 & LED (Auto stage II) system 7 ・ L-Mic stage with FTS, MC1362 (& LED) system 11 2) Automatic scanning and vertex recognition using E373 emulsion plates are now in progress. ・ An area of 15 mm x 15 mm of 16 E373 emulsion plates has been scanned and processed to search for hyper- nucleus events. ・ 42 multi-vertex events have been found. ・ Statistics will be doubled in 4 months. Fine Track Selector Wide-angle acceptance