1. L(1405)/S(1385) Photoproduction in SLH2 Deuk Soon Ahn

2. t-channel dynamics dominance Basic assumption: At E γ ≈ 2 GeV, the γ p → K + π 0 Λ and γ p→K + π Σ reactions in the region of the Σ(1385) and the Λ(1405) resonances are largely driven by the K - t-channel exchange. 1.t- channel dynamics, to gain understanding of the K-p-> π 0 Λ and of the K-p-> πΣ amplitudes below the KN thereshold, where they are dominated by the Σ(1385) and Λ(1405) resonances. 2. Ingoing photon dissociates into real K+ and virtual K-, the off-shell K-scattering subsequently off the proton target to the dsigma/dt with increasing |t|. (t means the square of the 4 momentum transfer from the proton to the L(1405)and S(1385)) 3. Theoretical differential cross sections for the γ p → K + (π 0 Λ) and γ p → K + (πΣ) reactions in the region of the Σ(1385) and the Λ(1405) resonances.(double kaon pole term contribution is large.) Nucl. Phys. A 748 (2005) 499

3. Old data: Production of hyperons by virtual photons T. Azemoon et al. NP B95 (1975) 77 e - p →e - K + Y Y = Λ, Σ, Σ(1385), Λ(1405), Λ(1520) Rapid fall-off suggesting a t-channel exchange process

4. w = (π Y) total center of mass energy The γ p → K + π 0 Λ and γ p → K + π Σ cross sections as functions of the total π Y center of mass energy for different values of E γ

5. W=1.415 W=1.425 W=1.405 W=1.395 W=1.435 Double pole term single pole term

6. Event Selction CutHORIVERTHORI+VERTComments Analyzed Event504039449070229947416 ntag=1327465030673226341972 Itagc.f>0340448032313796635859~4.6% increased ntrk>0259550624453905040896 K+ PID (3sigma)107031109822216853 DecayInFlight98961101267199958 e+e- bar9342396569189992 -1100<vtz<-900465294841294941 Vtz w/Cu cut453204728392603~2.5% decreased npl(1)=0.or.npl(2)=0441244592990053 1.91<Eg<1.93,2.27<Eg<2.30 448834675791640

7. MissingMass –Z-vertex CutZ-vertex, X-Vertex X-vertx, Y-vertex in the target region for double track events. Coming from target cell. Because of extended size of photon beam spot@target, (especially in Hori) part of photon beam hit the target cell(Cu) and events produced from there. -1000<vtz<-900-900<vtz<-800 -910<vtz<-900-900<vtz<-890 -1200<vtz<-1100-1100<vtz<-1000

8. Photon energy spectrum for ntag=1or2 events by kato’s itagc.f Rejected events by tagcut using npl Shieding materials are placed in High electron E of tagger(corresponding Low photon energy). There remains possibility that recoil electron with high energy outside the range of tagger. Or produce the shower at the material. npl1=0or npl2=0 is the number of hits which is not associated in PL. (selected event for which is no other hit than recoil electron, at least one of two. Because of a few dead stripes in SSD layer. We allow there is no hit in these strips to save tracks passed these area.

9. MissingMass & momemtum transfer MissingMass|t|-|t|min Counts

10. 0<|t|-|t|min<0.100.10<|t|-|t|min<0.20 0.20<|t|-|t|min<0.30 0.30<|t|-|t|min<0.40 0.40<|t|-|t|min<0.50 0.50<|t|-|t|min<0.60

11. MissingMass(GeV/c^2) Counts/5MeV MissingMass –E18bins (E1.5-2.4)

12. Photon Energy |t|-|t|min K+MissingMass L(1116) S(1193) S(1385)/ L(1116) L(1520)nonresont

14. Eg(GeV) MMp(g,K+) – all T &T1-T5 cut All |t|-|t|min 0.<|t|-|t|min<0.10 0.10<|t|-|t|min<0.200.20<|t|-|t|min<0.30 0.30<|t|-|t|min<0.40 0.40<|t|-|t|min<0.50

15. Differential cross section Minimum momemtum transfer |t|min varies drastically when photon energy changed. -> t’ = |t|-|t|min is introduced. ds/dt’ =a (exp(-bt)) b : slope ； The yield which is corrected acceptance is fitted with exponential function Photon normalization not included yet. dt A * (N K + - B) dd N B * N T * dt =

16. Yields of L(1116) as function of|t|-|t|min, Data |t|-|t|min Counts

17. Acceptance of L(1116) as function of |t|-|t|min, MC |t|-|t|min

18. dsigma/dt (Abr.Unit.) |t|-|t|min Differential Cross Section :Acceptance corrected yield|t|-|t|min distribution on L(1116)

19. Energy dependence of slope parameter b

20. Yields of L(1405)/S(1385) |t|-|t|min, Data |t|-|t|min Counts

21. Acceptance of L(1405) |t|-|t|min, MC |t|-|t|min

22. dsigma/dt (Abr.Unit.) |t|-|t|min Differential Cross Section of L(1405)/S(1385)

23. Energy dependence of slope parameter b

24. Yields of L(1520) |t|-|t|min, Data |t|-|t|min Counts

25. Acceptance of L(1520) |t|-|t|min, MC |t|-|t|min

26. dsigma/dt (Abr.Unit.) |t|-|t|min Differential Cross Section of L(1520)

27. Energy dependence of slope parameter b

28. Acceptance-corrected t’ ; 1.35<MM<1.44(9 MMslice)&E1-E9 1.35<MM<1.361.36<MM<1.371.37<MM<1.38 1.38<MM<1.391.39<MM<1.401.40<MM<1.41

29. 1.41<MM<1.421.42<MM<1.43 1.43<MM<1.44

30. Energy dependence of slope parameter b 1.35<MM<1.361.36<MM<1.371.37<MM<1.38 1.38<MM<1.391.39<MM<1.401.40<MM<1.41

31. 1.41<MM<1.42 1.42<MM<1.43 1.43<MM<1.44 1.37<MM<1.381.38<MM<1.391.39<MM<1.401.40<MM<1.411.41<MM<1.42 2.1<Eg<2.22.858961.534281.708531.786592.09702 2.2<Eg<2.31.938962.370781.766261.515461.70541 2.3<Eg<2.41.504792.933342.211052.216283.36527 b parameter