Development of automatic tracking particle of X to detect Double Hypernuclei (E07 in J-PARC) Kaori Umehara, Saeka Hataguchi, Asuka Fukunaga, Daisuke Yuzawa, Sayuri Niwa, Kaoru Hoshino, Kazuma Nakazawa Physics department of Gifu University, Japan

Status of X particle scanning system Plate of a section Up gel Base Down gel Upstream plate Downstream plate track 500mm 40mm SCIFI-Block Diamond (12C) target SCIFI-Bundle Emulsion stack X- LLZ LZ 1.67GeV/c K- p- K+ layered image of upstream and downstream Upstream track Downstream track E373 setup Move position of Ξ- particle to be followed Recognition of followed track Need human help Following track E07 is 10 times track of E373 →need high speed →automatic 17±9.2mm by alignment with gridmark position

1. Judgment of emulsion surface Full automated scanning system 1. Judgment of emulsion surface Take image (brightness average of 9×9pixel)－(brightness center of 9×9pixel)　 Sum of absolute value Judgment of up gel, base and down gel In gel →grain is black →different brightness of circumference of grain Sum ×104 Relation between sum and z direction z

1. Judgment of emulsion surface |(brightness average of 9×9pixel)－(brightness center of 9×9pixel)| 　　　　　＞　brightness threshold　→　1 　　　　　＜　brightness threshold　→　0 sum after binarization value　→　Judgment of up gel, base and down gel Sum ×104 Sum ×104 revision Compression that min become min after binarization z z |(brightness average)－(brightness center)| 　 　Binarization(brightness threshold 4)

2. Alignment with beams’ position Plate of a section track Take layered image Filtering Binarization Get outline of beams Pattern matching Up gel Base Down gel Upstream plate Downstream plate Up gel Base Down gel Take layered image in 2mm gap Image after filtering Image after binarization Image of outline of beams

2. Alignment with beams’ position Consistency of beam position (correspondence points inside circle) Take layered image Filtering Binarization Get outline of beams Pattern matching Upstream plate Downstream plate Image before alignment Upstream track Downstream track Image after alignment After check of consistency Position accuracy is obtained as 1.2±0.2mm.

3. Recognition of followed track Up gel base Down gel Upstream plate Downstream plate track Take track angle in the emulsion Take layered image Rotate the image Extract necessary part Take data position and angle Plate of a section Take position (x,y) and angle. x Taken angle Upstream plate Downstream plate

Part of 15mm length of the emulsion surface was not seen. z track q Upstream plate Downstream plate Layered image gap Up gel Base Down gel Plate of a section Part of 15mm length of the emulsion surface was not seen.

4. Following track Take track angle in emulsion Predict track from position, z gap and angle Move predicted track Recognition of track Take date position and angle Up gel Base Down gel Plate of a section track No recognition →think to be Xstop →follow track short gap of z →take image round Xstop

Summary Flow of fully automated scanning system Judgment of emulsion surface (up gel) Take beams’ position and brightness(Particle identification) Alignment with beams’ position Recognition of followed track Following track Judgment of emulsion surface (base) Following track+ Judgment of emulsion surface (down gel) Up gel Base Down gel Plate of a section E373 detected about 5 years → E07 about 50 years If we scan for 1 year 　・1day　20hours 　　1year　20[hours]×365[days]=7300[hours] 　　　　　≈2.6×107[s] 　・time to scan 1 track/plate 2.6×107[s]/(1.8×103[track]×110[mod]×6[plate]) 　　≈20[s/event]

Summary Judgment of emulsion surface is done by summing up binarized value. Alignment with beams’ position, recognition of followed track, and following track are done off line. Relation between gap and tanq was found. To drive the system on-line, the program is built in computer which controls the microscope.

Back　up

差=(emulsion内のmin)－(min) 表面認識(輝度閾値) 合計 ×104 Emulsion内のmin 差=(emulsion内のmin)－(min) 差 z min 輝度閾値

表面認識

表面認識(二値化) (9×9pixelの平均)－(9×9pixelの中心の輝度)の絶対値 ＞ 輝度閾値 → 1 ＜ 輝度閾値 → 0 　　　　　＞　輝度閾値　→　1 　　　　　＜　輝度閾値　→　0 二値化した値の合計 dB=(in　emulsion)-(out　emulsion) dB(二値化)/dB(輝度差) ≈2 合計 ×104 合計 ×104 補正 Minが同じになるように圧縮する Sum=0.051z2+48z+79000 Sum=0.059z2+43z+56000 z z 平均－輝度の絶対値　　　　　　　　　　　　　　　　二値化(輝度閾値4)

フィルター処理後 の画像 6×6フィルター

パターンマッチ 上流側 下流側 中点 up down θ 上流で引いた直線と下流で引いた直線の中点を合わせ、中点周りに下流の点を回転

Relation remainder between remainder and brightness threshold Up gel Base Down gel Plate of a section z Relation remainder between remainder and brightness threshold remainder ×103 Remainder =(min in emulsion)－(min) Brightness threshold

Emulsionの削れ 上流plate 下流plate z track q gap

Up gel Base Down gel Plate of a section 50mm track

4. Following track 角度を取得 重心と角度の情報から、Trackの位置を予測 予測された位置へ移動 →Xstopがあると考える →stopがあると考える間を細かく見る →stop点まわりの画像を取得 Up gel Base Down gel Plate of a section track