HLAB meeting status report

1. HLAB meetingstatus report Toshiyuki Gogami 3Sep2013

2. Contents K+Λ, K+Σ0 cross section

3. 12C(e,e’K+)12ΛB JLab E05-115, Carbon (112mg/cm2) pΛ sΛ Quasi-free Accidental background

4. K+Λ , K+Σ0 cross sections γ(*) + p  K+ + Λ γ(*) + p  K+ + Σ0 SAPHIR : K.H. Glander et al. , Eur. Phys. J. A 19, 251-273 (2004) CLAS : R. Bradford et al. , Phys. Rev. C 73, 035202 (2006) JLab E94-107 : P. Markoviz et al. , Proceedings of SENDAI08 (2009) JLab E91-016 : F. Dohrmann et al. , arXiv 0707.3059v2 (2007)

5. Definition of the cross section • The number of VP • Including HES solid angleand acceptance • Solid angle of HKS • Event by event

6. Missing mass spectrum Polyethylene target (0.45 mg/cm2)

7. After B.G. subtraction

8. Hydrogen reduction correction Figure: An photograph before and after the beam irradiation on the targets.

9. H reduction factor& Run selection Target positions from EPICS 76363 165.276365 163.276366 163.276367 161.276368 161.276369 159.276370 159.276371 157.276372 157.276373 155.276374 153.276375 153.276376 151.276377 151.276378 149.276564 148.7476565 148.7476566 148.7476567 147.7476568 147.7476569 146.7476570 146.7476571 145.7476572 145.7476573 144.7476574 144.74 76336 185.276337 185.276338 185.276339 185.276340 185.276341 176.276342 176.276343 175.276344 175.276346 175.276347 174.276348 174.276349 173.276350 173.2 76351 172.276352 172.276353 172.276354 170.276355 170.276356 169.276357 169.276358 168.276359 168.2 76360 167.276361 167.276362 165.2 76313 136.7476314 136.7476315 136.7476316 138.7476317 138.7476318 140.7476319 140.7476320 142.7476321 142.7476322 186.276323 186.276324 186.276326 185.276327 185.276328 185.276329 185.276330 185.276331 185.276332 185.276333 185.276334 185.276335 185.2 78.6 ± 9.9 % @ 3649 μC /data/8d/gogami/MM/mm23/krd/lambda_reduction/targetpos/tpos2.dat

10. Angular and momentum acceptance HES HKS θKlabθKCM Q2 W~1.93 GeV

11. Results

12. 12ΛB g.s. from CH2 target 52 (15) (4) nb/sr Polyethylene target 101 (4) (38) nb/sr in JLab E01-011

13. K+Λ , K+Σ0 cross sections γ(*) + p  K+ + Λ γ(*) + p  K+ + Σ0 SAPHIR : K.H. Glander et al. , Eur. Phys. J. A 19, 251-273 (2004) CLAS : R. Bradford et al. , Phys. Rev. C 73, 035202 (2006) JLab E94-107 : P. Markoviz et al. , Proceedings of SENDAI08 (2009) JLab E91-016 : F. Dohrmann et al. , arXiv 0707.3059v2 (2007)

14. Hidden factor, 2 ?

15. Paper of bucking coil to NIMA( final procedure ) http://dx.doi.org/10.1016/j.nima.2013.08.047

16. Backup

17. Considered efficiencies Simulation JPS meeting in Kyoto , Toshi Gogami

18. Results

19. Outlook • Efficiencies • Target burn • Consistency check with H2O target Before Preliminary After JPS meeting in Hiroshima , Toshi Gogami

20. Experimental setup JPS meeting in Hiroshima , Toshi Gogami

21. Electro-production of K+Λ JLab E05-115 experiment by the (e,e’K+) reaction Small Q2 ( ~0.01 [GeV/c]2 )  almost real photon Real photon JPS meeting in Hiroshima , Toshi Gogami

22. e , e+ background in GEANT simulation • Generated particle : e+ • Distribution : spherical uniform • Momentum : 860 – 1000 [MeV/c] • Angle : 0 – 2 [mrad] • 1000 events e+ generated in target make HKS dirty Correlation B.G. mix rate (Real data) Number of e+ (Simulation) KDC1 KDC2 e- , e+ Vacuum chamber (sus304) NMR port (sus304) JPS meeting in Kyoto , Toshi Gogami

23. 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 JPS meeting in Kyoto , Toshi Gogami

24. Hit wires event display (2) 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’ JPS meeting in Kyoto , Toshi Gogami

25. Energy scale calibration e, K+ conversion • Λの絵 • 解析のながれ　 Angle, position @ FP Angle, momentum @ Target 6th order transfer matrix