HLab meeting Status report

1. HLab meetingStatus report T.Gogami 13/Sep/2011 12/Mar/2011 CNN News in D.C.

2. Contents • CH2 & H2O Λ issue • ¼ σΛ(CH2) = σΛ(H2O) • Develop Tracking code

3. Experimental setup of JLab E05-115 p(e,e’K+)Λ,(Σ0)

4. Experimental setup of JLab E05-115 p(e,e’K+)Λ,(Σ0) HES e’ Splitter Magnet HKS K+

5. Analysis process HES HKS tracking tracking JLab E05-115 p(e,e’K+)Λ,Σ0 x , x’ , y , y’ at Reference plane x , x’ , y , y’ at Reference plane ~40 hours (5 shifts) Very preliminary F2T function F2T function x’ , y’ , p at Target x’ , y’ , p at Target particle ID (select K+) Missing Mass tune tune p : Λ , Σ0 ,12ΛB Angle : Sieve slit

6. Multiplicity of typical layer of chamber HES HKS ~1.13 ~2.24 ~4.94 ~1.28 Multiplicity is high for HKS

7. Hit wires in KDC1 KDC1 Overhead view Overhead view Misidentification chance in hit wires selection increase ! low high low high REAL DATA REAL DATA Black : hit wires Blue : selected wires Red : track Black : hit wires Blue : selected wires Red : track CH2 52Cr

8. Basic tracking procedure Real data 52Cr target CH2 target Good TDC High multiplicity Pattern recognition Black : hit wires Blue : selected wires Red : track KDC1 Solve left right Select good combination Combination selection with TOF counters Reduce hit wire combinations (h_tof_pre.f) Track fit

9. New tracking scheme • Hit wire selection with TOF • 1X & 2X • Grouping • Pre-PID • Cherenkov detectors Good TDC みそ High multiplicity Pattern recognition Reduce hit wires to analyze Solve left right Select good combination Combination selection with TOF counters Reduce hit wire combinations (h_tof_pre.f) Track fit

10. DC hit info. selection with TOF (xx’) Just applied to xx’-layers for test Gravity CUT Particle direction ~17% Selective region Maximum gradient ~8% CUT Minimum gradient Procedure in “h_dc_tofcut.f” Get KTOF1X & 2X hit counter information Make combination of 1X and 2X hit counter if those two are in same group (grouping) Determine cut conditions on KDC1 & KDC2 Select Hit wires in KDC and Reorder them

11. Check works of the code Gravity • GREEN region Selective region • RED markers Selected hit wires • BLACK markers Rejected hit wires Particle direction Seems to work well

12. Results of TOF cut withgrouping Residual before after CH2 , 2.0 [μA] , 76315 Same σ 150 [μm] σ 150 [μm] Multiplicity CH2 , 2.0 [μA] , 76315 x’ x’ x x Shift ~1.2 ~2.3

13. Apply to u,v-layer v v’-layer Selective region determined by 1X and 2X Applied to uu’ and vv’ layers , too. Convert xx’-layer

14. Check works of the code KDC1 KDC2 v v’ v v’ uu’ uu’ • GREEN regionSelective region • RED markers & linesSelected hit wires • BLACK markers & lines Rejected hit wires particle particle x x’ x x’

15. Results of TOF cut withgrouping (all layers) Residual before after CH2 , 2.0 [μA] , 76315 σ 150 [μm] σ 150 [μm] Same Multiplicity • Multiplicity of uu’vv’-layers • CH2 • ~20% reduction • 52Cr • ~5-10% reduction

16. Results of TOF cut withgrouping (all layers) CH2 TOF cut works well Faster ! Increase ! 52Cr Faster ! 52Cr Increase ! Parameters ?

17. DC hit info. selection with TOF Stricter TDC cut Gravity CUT Particle direction ~17% Selective region Maximum gradient ~8% CUT Minimum gradient

18. Results of Introduction new code CH2 Increased ! 52Cr Increased !

19. Summary • CH2 & H2O Λ issue • Improvement of tracking code • ¼ σ(CH2) = σ(H2O) ==> ½ σ(CH2) = σ(H2O) • Virtual photon flux calc. • efficiency

20. End

21. Multiplicity improvement history Applied TDC cut Multiplicity went down ! • Analysis time • 20% reduction for 52Cr • Number of Kaon (RUN:77124, 52Cr) • 56  70  90  130 DC TOF cut Matrix DC TOF cut ‘ (TDC cut)

22. Result of TOF cut withgrouping Original code KDC allowance select Pure Selective region allowance With “h_dc_tofcut.f” Optimal allowance Number of K+ ~2[%] up Good tracks hid by background appear ! Too strict

23. Experimental setup of JLab E05-115 Position, angle e’ K+ Position, angle

24. Experimental setup of JLab E05-115 Position, angle e’ Momentum vector K+ Position, angle

25. Experimental setup of JLab E05-115 JLab E05-115 p(e,e’K+)Λ,Σ0 ~40 hours (5 shifts) Missing Mass Very preliminary Momentum vector

26. KTOF TDC • Cut 10000 – 50000 (Current) 18000 – 20500 (New) Run 76314 for CH2 target Run 77124 for 52Cr target

27. Data Summary JLab E05-115 (2009/June – 2009/Nov)