1. Update of  Analysis ~LEPS Collaboration Meeting in Taiwan Nuclear Physics Group, Academia Sinica Bo-Ru, Lin 2006/01/12

2. Outline Φ photoproduction using LD2 target Validity of momentum calculation Determination of Eγ smearing Determination of Appropriate mass offshell effect t-resolution dN/dt fitting Background estimation

3. Φ -photoproduction using LD2 target. p, n, or D ? Incoherent Interaction ： Photon interact with constituent nucleon, which is proton or neutron. Coherent Interaction ： Photon interact with deuteron as a whole.

4. Isospin effect in Coherent production η: isoscalar π: isovector D : isoscalar  : isoscalar Allowed Forbidden By isospin conservation we should be able to separate π from the whole exchanging channels. Conjecture ： Pseudo-scalar Exchange

5. MMd of LD2, and LH2 Missing mass distributions provide us a tool. LD2LH2

6. Validity of momentum Calculation Accredited Md = 1.875 GeVAccredited MΛ = 1.520 GeV

7. Validity of momentum Calculation Accredited Mp = 0.938 GeV

8. Validity of momentum Calculation Accredited MΦ = 0.938 GeV

9. Determination of appropriate MC Eγ smearing 15 Mev Smearing MMp fitting of LH2 real data using different Eγ smearing

10. Determination of appropriate Eγ smearing 10 Mev Smearing Two component (11.64 MeV) Smearing

11. Determination of Appropriate mass offshell effect Use MC Incoherent MMd fit LD2 MMd (in the region 1.9~2.1) Do subtraction and fit with gaussian distribution. Compare the result with coherent distribution

12. Determination of Appropriate mass offshell effect

15. t - resolution ~ sigma plot The t-resolution is better than 0.02 GeV Fit (t-in) – (t-out) with gaussian distribution to get σ value t-in : from event generator t-out : deduced in the way the same as real data

16. MMd Fitting to Separate Coherent from Incoherent events Fitting of MMd of LD2 real data using Mote-Carlo generated incoherent, coherent events. coherent incoherent sum

17. Cross check of MMd, and MMp Fitting MMd MMp

18. Coherent LD2 dN/dt Fitting Fitting Formula ： intercept slope

19. Coherent LD2 dN/dt Fitting t bin : 30 MeV t bin : 20 MeV t bin : 40 MeV

20. Coherent LD2 Common slope dN/dt Fitting t bin : 30 MeV t bin : 20 MeV t bin : 40 MeV Slope : 20~23 Slope with last Eγbin removed : 17 ~19

21. Incoherent LD2 dN/dt Fitting

22. Incoherent LD2 Common slope dN/dt Fitting

23. dN/dt Fitting of coherent, incoherent, LH2 results LH2 Incoherent Coherent Coherent Slope : ~18.5 Incoherent Slope : ~4.0 LH2 Slope : ~3.6

24. Background Estimation 10 Mev cut

25. MC Backgrounds None-resonant KKn Λ(1520) None-resonant KKd Invm-kkMMpMMd

26. Multidimensional Fitting Invm-KKMMdMMp LD2 Data Incoherent Coherent Sum of all Fit invm-KK, MMd, MMp simultaneously without background.

27. Multidimensional Fitting Invm-KKMMdMMp LD2 Data Incoherent Coherent Sum of BG Sum of all KKd Sum of BG Λ(1520) KKn

28. Multidimensional Fitting Invm-KKMMdMMp LD2 Data Incoherent Coherent Sum of BG Sum of all Next step : Apply the same procedure with t-binning

29. Brief Summary Stable results of preliminary dN/dt analysis are acquired. Background estimation in every t, Eγ bin to acquire pure Φ events. Thank you for paying attention

30. Backup Slides

31. MMd MMd, using smaller binning

32. Determination of Appropriate mass offshell effect ~ Results of other Ntuples