HLAB meeting status report Toshiyuki Gogami 3Sep2013 Contents K+Λ, K+Σ0 cross section 12C(e,e’K+)12 ΛB JLab E05-115, Carbon (112mg/cm2) sΛ pΛ Quasi-free Accidental background 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) Definition of the cross section The number of VP • Including HES solid angle and acceptance Solid angle of HKS Event by event Missing mass spectrum Polyethylene target (0.45 mg/cm2) After B.G. subtraction Hydrogen reduction correction Figure: An photograph before and after the beam irradiation on the targets. H reduction factor & Run selection Target positions from EPICS 76313 136.74 76314 136.74 76315 136.74 76316 138.74 76317 138.74 76318 140.74 76319 140.74 76320 142.74 76321 142.74 76322 186.2 76323 186.2 76324 186.2 76326 185.2 76327 185.2 76328 185.2 76329 185.2 76330 185.2 76331 185.2 76332 185.2 76333 185.2 76334 185.2 76335 185.2 76336 185.2 76337 185.2 76338 185.2 76339 185.2 76340 185.2 76341 176.2 76342 176.2 76343 175.2 76344 175.2 76346 175.2 76347 174.2 76348 174.2 76349 173.2 76350 173.2 76351 172.2 76352 172.2 76353 172.2 76354 170.2 76355 170.2 76356 169.2 76357 169.2 76358 168.2 76359 168.2 76360 167.2 76361 167.2 76362 165.2 76363 165.2 76365 163.2 76366 163.2 76367 161.2 76368 161.2 76369 159.2 76370 159.2 76371 157.2 76372 157.2 76373 155.2 76374 153.2 76375 153.2 76376 151.2 76377 151.2 76378 149.2 76564 148.74 76565 148.74 76566 148.74 76567 147.74 76568 147.74 76569 146.74 76570 146.74 76571 145.74 76572 145.74 76573 144.74 76574 144.74 /data/8d/gogami/MM/mm23/krd/lambda_reduction/targetpos/tpos2.dat 78.6 ± 9.9 % @ 3649 μC Angular and momentum acceptance HES Q2 W~1.93 GeV θKlabθKCM HKS Results Θlabe [rad] θCMK [rad] Q2 [GeV/c]2 Λ (CMS) [nb/sr] Σ0 (CMS) [nb/sr] 0.030-0.050 0.27 0.003 166 (17) (32) 55 (29) (10) 0.050-0.070 0.26 0.007 155 (18) (29) 51 (30) (10) 0.070-0.100 0.27 0.013 159 (18) (30) 81 (29) (17) 0.030-0.100 0.27 0.007 164 (10) (31) 78 (17) (15) 12 ΛB g.s. from CH2 target Polyethylene target 52 (15) (4) nb/sr 101 (4) (38) nb/sr in JLab E01-011 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) Hidden factor, 2 ? Paper of bucking coil to NIMA ( final procedure ) http://dx.doi.org/10.1016/j.nima.2013.08.047 Backup Considered efficiencies Simulation 2012/9/14 JPS meeting in Kyoto , Toshi Gogami 17 Results Θlabe [rad] θCMK [rad] Q2 [GeV/c]2 Λ (CMS) [nb/sr] Σ0 (CMS) [nb/sr] 0.030-0.050 0.27 0.003 166 (17) (32) 55 (29) (10) 0.050-0.070 0.26 0.007 155 (18) (29) 51 (30) (10) 0.070-0.100 0.27 0.013 159 (18) (30) 81 (29) (17) 0.030-0.100 0.27 0.007 164 (10) (31) 78 (17) (15) Θlabe [rad] θCMK [rad] Q2 [GeV/c]2 Λ (CMS) [nb/sr] Σ0 (CMS) [nb/sr] 0.000-0.250 0.20 0.007 291 (32) (55) 176 (12) (33) 0.000-0.250 0.35 0.007 176(12) (33) 53 (24) (10) 0.000-0.250 0.27 0.007 198(12) (28) 72 (20) (5) Outlook • Efficiencies • Target burn • Consistency check with H2O target Before After 2013/3/27 JPS meeting in Hiroshima , Toshi Gogami 19 Experimental setup 2013/3/27 JPS meeting in Hiroshima , Toshi Gogami 20 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 2013/3/27 JPS meeting in Hiroshima , Toshi Gogami 21 e , e+ background in GEANT simulation e+ generated in target make HKS dirty Number of e+ Correlation (Simulation) KDC1 B.G. mix rate (Real data) KDC2 e- , e + Vacuum chamber (sus304) 2012/9/14 NMR port (sus304) • Generated particle : e+ • Distribution : spherical uniform • Momentum : 860 – 1000 [MeV/c] • Angle : 0 – 2 [mrad] JPS meeting in Kyoto , Toshi Gogami 22 • 1000 events Apply to u,v-layer v v’-layer Selective region determined by 1X and 2X Convert x x’-layer 2012/9/14 Applied to uu’ and vv’ layers , too. JPS meeting in Kyoto , Toshi Gogami 23 Hit wires event display (2) v v’ u u’ v v’ u u’ particle particle x x’ x x’ • GREEN region Selective region • RED markers & lines Selected hit wires • BLACK markers & lines Rejected hit wires 2012/9/14 JPS meeting in Kyoto , Toshi Gogami 24 Energy scale calibration e, K+ conversion • Λの絵 • 解析のながれ
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