Track ranking in CS analysis

T. Fukuda

20/Jan ‘09 OPERA–JAPAN (Mizunami) meeting

Aim

• Saving manual check load in CS analysisby picking up only track whose quality is like real track.

Track rankingAfter preparing 4/4 and ¾ track,

we evaluate track quality. Track ranking4/4 3/4

VPH x 4surface (VPH is darkness of track),Delta-angle(base-micro) x 4surface x 2projection,Delta-angle(base1-base2) x 2projection total 14 parameter @4/4track (total 9 parameter @3/4track) calculation of chi-square probability

CS2

CS1

VPH distribution

This sample is CS track already found during 08’July-08’October. Investigated VPH distribution of micro track every 100mrad.

VPH (0.0rad-0.1rad)

VPH (0.1rad-0.2rad)

VPH (0.2rad-0.3rad)

VPH (0.3rad-0.4rad)

VPH (0.4rad-0.5rad)

VPH (0.5rad- )

Delta-angle(base-micro)Sample track is same on the case of PH.Investigated delta-angle between Base track and Micro track each angle and each ph (angle:every 150mrad, ph:6-8,9-12,13-16),

dAx (0.0rad-0.15rad,PH13-16) dAx (0.0rad-0.15rad,PH9-12) dAx (0.0rad-0.15rad,PH6-8)

dAx (0.15rad-0.3rad,PH13-16) dAx (0.15rad-0.3rad,PH9-12) dAx (0.15rad-0.3rad,PH6-8)

Sigma=22mrad

Sigma=15mrad Sigma=18mrad Sigma=18mrad

Sigma=27mrad Sigma=30mrad

(0.3rad-0.45rad) :Sigma = 35mrad(PH13-16), Sigma = 40mrad(PH9-12), Sigma = 47mrad(PH6-8),(0.45rad-0.6rad) :Sigma = 55mrad(PH13-16), Sigma = 61mrad(PH9-12), Sigma = 70mrad(PH6-8)

Delta-angle (base1-base2)dAy (0.0rad-0.1rad) dAy (0.2rad-0.3rad) dAy (0.4rad-0.5rad)

dAy (0.1rad-0.2rad) dAy (0.3rad-0.4rad) dAy (0.5rad-)

Sample track is same.Investigated delta-angle between Base track(CS1) and Base track (CS2) every 100mrad.This parameter is applied in the case of 4/4 track.

Sigma=5mrad

Sigma=6mrad

Sigma=8mrad

Sigma=9mrad

Sigma=8mrad

Sigma=8mrad

Chi-square distribution

A B C D E

Track ranking is used Chi-square probability.VPH distribution is not gauss distribution. So, distribution converted to gaussian for applying chi-square technique.

Chi-square like distribution of found real track

Quality LevelA: 0.0 – 0.9 (33%)B: 0.9 – 1.4 (34%)C: 1.4 – 2.0 (20%)D: 2.0 – 3.0 ( 9%)E: 3.0 – (4%)

Plot is chi-square like distribution using 14 parameter (4/4 track). Left one is real track, Right one is fake track. I give quality level (A-E)to each track.

A B C D E

Chi-square like distribution of typical fake track

4/4 trackXray alignment +- 50micron120cm2, <0.7rad

CS - Manual checkNow we are applying track ranking to all CS-Manual check.We check manually as following procedure.

1. I check compton alignment map and judge to use or not.2. I control number of tracks should be checked.

[Normal case] CC event : 4/4track top10-top20, and muon hunting (3/4, 4/4) NC event : 4/4track top10-top20, and 3/4track top10

Compton Alignment success

227471534\9197212 237862770\15109010

Compton Alignment partly success Miyamoto

This is CS analysis result sheet.Each Track ranking is given automatically.

Recent result of manual check. ( 401trks in 29events )

A B C D E

Real trk 70 55 33 9 1

Fake trk 1 19 51 98 64

After manual check,• Found track – TT hit matching• Event validation• Brick request• Decision of location method (SBL/DVh)

Summary• I’m developing Track Ranking method for

effective manual check.• Now in CS analysis @Nagoya, basically this

method is applying for all CS-manual check.• The number of tracks should be manual

checked is 10-30tracks.

Next step

• Improvement of weight considered to S/N.• Investigation of possibility of automatic track selection (no manual check ! ) CS team people start to Decay Search !

Chi-square distribution

A B C D E

Track ranking is used Chi-square probability.VPH distribution is not gauss distribution. So, distribution converted to gaussian for applying chi-square technique. - procedure of conversion, for example, (0.0rad-0.1rad) : [VPH:35-39] [65-70%67.5%] [0.98sigma] (0.0rad-0.1rad) : [VPH:56-60] [35-40%37.5%] [0.49sigma]

Chi-square like distribution of found real track

Quality LevelA: 0.0 – 0.9 (33%)B: 0.9 – 1.4 (34%)C: 1.4 – 2.0 (20%)D: 2.0 – 3.0 ( 9%)E: 3.0 – (4%)

Plot is chi-square like distribution using 14 parameter (4/4 track). Left one is real track, Right one is fake track. I give quality level (A-E)to each track.

A B C D E

Chi-square like distribution of typical fake track

4/4 trackXray alignment +- 50micron120cm2, <0.7rad