HES-HKS & KaoS meeting

1. HES-HKS & KaoS meeting Toshiyuki Gogami 18Dec2013

2. Missing mass Resolution • Intrinsic mass resolution • Production point displacement from the matrix origin • Mass offset due to energy loss in target

3. Intrinsic mass resolution • Energy straggling, raster and mass offset are not included in these estimation • Total resolution cannot be a simple quadratic sum since variables are not independent • (but, simple quadratic sum is shown as an intrinsic resolution here)

4. Production point displacement from the matrix origin (z-direction) 730 keV 580 keV Effects are smaller (<0.1 MeV/c2) for other targets since their thickness are less than 0.05 cm. These effects are implicitly absorbed by matrices in a process of tuning (already checked in blind analysis) NOTE

5. K+ Energy loss correction(Before talking about mass offset) e’ Target e Production at the center of target Missing mass after energy loss correction Most probable value for each particle  Energy loss correction value

6. K+ Energy loss correction(Before talking about mass offset) e’ Target e Production at the center of target Missing mass after energy loss correction Most probable value for each particle  Energy loss correction value

7. e : ~2δEe e’ : 0 K+ : 0 Mass offset due to energy loss e : 0 e’ : ~2δEe’ K+ : ~2δEK Most probable values z Target ~ 0.7 MeV (hand calc. 0.67 MeV)

8. In the case of 7ΛHe Matrix Matrix + MM offset + others 0.58 MeV 1.4 MeV Others = 1.4 – 0.58 = 0.82 [ MeV ] Offset: 0.7 MeV, intrinsic: 0.4 MeV Sqrt(0.7*0.7 + 0.4*0.4) = 0.8

9. Achievable resolution Simply subtracted matrix z dependence

10. Blind analysis • The first results

11. Flow chart of blind analysis Blind Compare

12. Flow chart of blind analysis Imitation data generation Distorted matrix generation Tuning Comparison tuned results with generated data Major four parts • Systematic errors • Binding energy • Cross section

13. The first sample Tune with Λand Σ0 with realistic B.G. shape

14. Missing mass • Restarted tuning…. • With new energy loss corrections for 12C target • 112.5  87.5 mg/cm2 (ELOG)

15. Carbon target 700 keV (FWHM)

16. Lithium target 1000 keV (FWHM)

17. 720 keV (FWHM)

18. Summary • Resolution estimation • Estimation will be improved soon • Blind analysis • The first results (delta BΛ< 100 keV) • Matrix tuning • restarted

19. Backup

20. Li target

22. z Production point displacement from the matrix origin (x-direction) x Target x-dependence x,y and z random generation with target x and y random generation without target x includes information of z because the target is tilted  A pure effect from the x-dependence is compensated by the z-dependence

23. Production point displacement from the matrix origin (y-direction) y-dependence x,y and z random generation with target x and y random generation without target

24. K+ Energy loss correction(Before talking about mass offset) e’ Target e Production at the center of target Missing mass after energy loss correction Most probable value for each particle  Energy loss correction value

25. Spectrometer resolution

26. z e : ~2δEe e’ : 0 K+ : 0 Mass offset e : 0 e’ : ~2δEe’ K+ : ~2δEK Most probable values Target Simply calculated by where A, B and C are defined in page 4.

27. z Most probable values e : ~2δEe e’ : 0 K+ : 0 Mass offset Target e : 0 e’ : ~2δEe’ K+ : ~2δEK Simply calculated by where A, B and C are defined in page 4.

28. Want to understand simulated results (resolution)

29. Energy loss correlation Bug fixed in POSI  Expected correlation can be seen now.