HES-HKS & KaoS meeting Toshi Gogami 31/Jan/2012

Contents K+ cut efficiency

HKS detectors − π+ K+ p K+ p, π+ 1 [m] HKS trigger CP = 1X ×1Y × 2X June 2009 in JLab Hall-C 1 [m] HKS trigger CP = 1X ×1Y × 2X K = WC × AC  CP × K − π+ K+ p ~18 [kHz] (8 [μA] on 52Cr) K+ p, π+ Cherenkov detectors -AC,WC- Aerogel (n=1.05) Water (n=1.33) Drift chambers -KDC1,KDC2- TOF walls -2X,1Y,1X- (Plastic scintillators) σ ≈ 250 [μm] TOF σ ≈ 170 [ps] Strangeness 2010 at KEK

K+ cut efficiency π+ p K+ π+ p K+ K+ survival ratio after AC npe sum WC NPE cut AC NPE cut Mass square cut Coincidence time cut π+ AC npe sum p K+ π+ WC npe sum p K+ Mass square

K+ survival ratio after AC cut (CH2) looser cut of AC NPE p K+ π+ Stricter cut of AC NPE p (accut,wccut) = (5,-0.1) pi suv. ratio: 0.0631439+-0.00148976 K  suv. ratio: 0.876875+-0.00513167 p  suv. ratio: 0.911427+-0.0023794 (accut,wccut) = (10,-0.1) pi suv. ratio: 0.105762+-0.0019663 K  suv. ratio: 0.931211+-0.00536427 p  suv. ratio: 0.94023+-0.00243485 (accut,wccut) = (15,-0.1) pi suv. ratio: 0.141455+-0.00231043 K  suv. ratio: 0.956913+-0.00547386 p  suv. ratio: 0.960014+-0.00247285 K+ π+

K+ survival ratio after WC cut (CH2) looser cut of WC NPE p K+ π+ Stricter cut of WC NPE (accut,wccut) = (2000,1.1) pi suv. ratio: 0.922368+-0.00752531 K  suv. ratio: 0.987653+-0.00566791 p  suv. ratio: 0.133889+-0.000701787 (accut,wccut) = (2000,1) pi suv. ratio: 0.963952+-0.00777583 K  suv. ratio: 0.989093+-0.0056741 p  suv. ratio: 0.176933+-0.000821917 (accut,wccut) = (2000,0.9) pi suv. ratio: 0.971601+-0.00782181 K  suv. ratio: 0.999575+-0.00571909 p  suv. ratio: 0.259314+-0.00102927 K+ p π+

K+ survival ratio after AC, WC cut (52Cr) まぁまぁ K+ Increase… ! K+ π+ p π+ (accut,wccut) = (7,-0.1) pi suv. ratio: 0.065416+-0.000449255 K suv. ratio: 0.586117+-0.00452555 p suv. ratio: 0.651355+-0.00184533 (accut,wccut) = (10,-0.1) pi suv. ratio: 0.0798301+-0.000499635 K suv. ratio: 0.633024+-0.00477219 p suv. ratio: 0.715314+-0.0019709 (accut,wccut) = (12,-0.1) pi suv. ratio: 0.106535+-0.00058428 K suv. ratio: 0.576053+-0.00447227 p suv. ratio: 0.750981+-0.00204033 (accut,wccut) = (2000,1.2) pi suv. ratio: 0.97553+-0.0026548 K suv. ratio: 1.04522+-0.00476197 p suv. ratio: 0.306715+-0.00108176 (accut,wccut) = (2000,1.1) pi suv. ratio: 0.980888+-0.00266569 K suv. ratio: 1.04946+-0.00477655 p suv. ratio: 0.342593+-0.00115887 (accut,wccut) = (2000,1) pi suv. ratio: 0.999912+-0.00270431 K suv. ratio: 1.04956+-0.00477692 p suv. ratio: 0.382421+-0.0012424

Need to improve the fitting WC NPE1+2 > 0.1 Stricter cut WC NPE1+2 > 0.4 WC NPE1+2 > 0.6 K+ increase Fitting is not going well…. Pre π+ cut Cut low and high mom segments separately

学会の移動+宿 伊丹空港 関西学院大学 梅田 飛行機往復 + ホテル4泊(ホテルコムズ大阪、朝食付き) = 50,800円

Summary & outlook Summary Outlook K+ cut efficiency E01-011 E05-115 Need to fit mass square distribution for high multiplicity data. Outlook E01-011 ENGE + SPL GEANT4 TOSCA　来週千賀さんと E05-115 Trigger efficiency (Chiba study) Tracking efficiency K + Cut efficiency for high multiplicity data Matrix SNP2012 2/12- 2/18 J-PARC, Tohoku Univ. , Sakunami GCOE 国際シンポジウム 2/20 – 2/22 Tohoku Univ. JLab 出張 3/6 – 3/21 物理学会 (関西学院大学) 3/23 – 3/27 (前日入り)

END 26/Jan/2012, 愛宕神社