Study of double hypernucleiwith a general scan

Kyoto University

Department of Physics

Toshinao Tsunemi

Masashi Hayata(Kyoto Univ.) Ken-ichi Imai (Kyoto Univ)Kazuma Nakazawa(Gifu Univ.) Takaomi Watanabe(Gifu Univ.)

outline

• KEK-E373　 emulsion

• image scan by human brain

• Neural network on a computer

• Simplify the recognized lines

• Summary

KEK-E373

There are more eventsNAGARA event

1) Online trigger efficiency2) Other decay channel (neutral particle)

A couple of dozendouble hypernuclear eventsin the emulsions of KEK-E373

If we can establish a general scan, we canfind a couple of dozen double hypernuclear events.

New microscope

CCD 1 M pixelsShutter 100 HzLED light

Depth of field 5m

Recognize a line

• There is a vertex in a double hyper or single hypernuclear event

Recognize a line

Reconstruct a vertex

We are working on recognizing a line now.

Photo from CCD of the microscope

How our brain works?

44

0 p

ixe

l

512 pixel

Human brain

Picture is cited from

Human brain

Picture is cited from

■is related to the first stage of visual sense

line recognition with a neural networkon a computer

512 pixel

440

pixe

l

32 pixel

Neural network

14 line types

Scan a picture by32pixel * 32pixel region

1024

16

140 1 2 3 4

5 6 7 8 9

10 11

input

Neural network 　（ perceptron ）

Input layer 32*32 pixel=1024Hidden layer 16Output layer 14

Learning with a teacher （ Back Propagation method）

12 13

Learning stage

1024

16

14

output

Neural network 　（ perceptron ）

Input layer 32*32 pixel=1024Hidden layer 16Output layer 14

Learning with a teacher （ Back Propagation method）

0 1 2 3 4

5 6 7 8 9

10 11 12 13

image

32px

32

px

output stage

x160 y360out: 0 1.4795e-005out: 1 2.75203e-007out: 2 0.000210363out: 3 0.00443625out: 4 0.0644443out: 5 0.267729out: 6 1.06818e-005out: 7 4.04745e-006out: 8 5.06837e-005out: 9 0.00151709out: 10 0.00128184out: 11 0.101609out: 12 0.000494124out: 13 0.00069409

x240 y120out: 0 8.49013e-005out: 1 8.02295e-008out: 2 0.000253557out: 3 0.00104015out: 4 0.00361907out: 5 0.00362555out: 6 0.00954602out: 7 8.22062e-005out: 8 2.11628e-005out: 9 0.325218out: 10 0.0111719out: 11 4.35869e-006out: 12 0.00043366out: 13 0.000240392

x376 y248out: 0 0.0592193out: 1 0.00778189out: 2 0.000285482out: 3 1.36718e-006out: 4 4.66565e-005out: 5 3.8341e-006out: 6 7.36192e-006out: 7 0.0271225out: 8 0.00216796out: 9 2.48886e-005out: 10 0.000181834out: 11 0.00517701out: 12 0.000111058out: 13 0.0130495

input

Pattern 5

Pattern 9

Pattern 0

1

2

3

4

5

6

7

89

10

11

12

13

14

Result of pattern match

simplify

Successive lines with same decline are to be a line.

Future plan

Reconstruction of lines in 3 dimensional space

summary

• A couple of dozen hypernuclear events are in the emulsion of the KEK-E373.

• Method of a general scan is developing.