HES-HKS & KaoS meeting

Toshiyuki Gogami8/Nov/2012 From Mainz

5/Nov/2012 @ A1 Exp. Hall

Contents

• Energy loss study– K+ : HKS Geant4– e’ : HES Geant4– e : Modified POSI Geant4

Energy LossPrediction ;Landau distribution with uniformly floating peak value

Like these ??

Log scale

ただの予想 (シミュレーションではない )

Energy loss simulation by HES,HKS and POSI

1. POSI for beam energy loss– Harver foil is already implemented in this code.– Implemented Raster newly.

2. HKS, HES for K+ and e’ energy loss– Transplant harver foil into these code from POSI.

• バグだし(HES、 HKS)変数の定義の間違え・・・昔からあるようだが。。(POSI)Rasterを入れる際のバグ… .etc

• New ver. GEANT では動かない問題 (HES,HKS)コンストラクターの引数の数、順番G4ThreeVector…..etc日本で解決済

Beam Energy Loss study

Used Geant4 simulation code “Modified POSI”Water ( + harver ) target in the display

Virtual Detector

TargetGeneration point(Uniform in z-direction)

SIMULATION

Energy loss distribution of the simulation

Fitted by landau function just for edge and tail portion

Boron , 56.1 mg/cm2

Determination of the value of energy loss

This edge is the peak value which is derived by the fitting results

EDGE

31 keV

Boron , 56.1 mg/cm2

Water target with Harver foils

EDGE

371 keV

Harver foil effect Water

water

Foil

Simulation ResultsTarget < 5 MeV < 1 MeV < 0.5 MeV Kawama Toshi7Li 160

137141121

133115

133 10389

9Be 161141

140122

132115

177 (Chen) 10190

10B 5548

4740

4539

45 3127

12C 11197

9482

8977

90 6658

52Cr 151140

113101

10493

94 7971

Water + Harver

552 429 251 442*1.6 371

Polyethylene 500436

406362

240241

440 * 0.8 349296

Unit : keV

Filling Blanks now

Wiki

• 資料アップお願いしますhttp://lambda.phys.tohoku.ac.jp/~db/mediawiki/index.php/%E7%99%BA%E8%A1%A8%E8%B3%87%E6%96%99

• Mainz　メンバー更新しましたhttp://lambda.phys.tohoku.ac.jp/~db/mediawiki/index.php/Mainz_Members

Outlook

• Λ cross section– Polyethylene

• Divide by several bins ( <=4 )• Check acceptance estimation

– Water• Estimate efficiencies

Discuss with Patrick (Before leave Mainz)• Matrix tuning– Fixed small Bugs– See how will it work with new energy loss estimations– Want to try to use better S/N events (tight cut)– Want to put Λ,Σ0 events from water target to good use.

END