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HES-HKS analysis meeting. 30 Aug 2013 Toshiyuki Gogami. Contents. Cross section of elementary processes Introduction Correction factors K + decay factor H reduction Results Bucking coil. K + Λ , K + Σ 0 cross sections. Preliminary 85 ± 13 ±34. Preliminary 200 ± 16 ± 91.
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HES-HKS analysis meeting 30Aug 2013 Toshiyuki Gogami
Contents • Cross section of elementary processes • Introduction • Correction factors • K+ decay factor • H reduction • Results • Bucking coil
K+Λ , K+Σ0 cross sections Preliminary 85 ± 13 ±34 Preliminary 200 ± 16 ± 91 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)
Angular and momentum acceptance HES HKS θKlabθKCM Q2 W~1.93 GeV
Definition of cross section • The number of VP • Including HES solid angleand acceptance • Solid angle of HKS • Event by event
Hydrogen reduction correction Figure: An photograph before and after the beam irradiation on the targets.
H reduction factor& Run selection Target position 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 % /data/8d/gogami/MM/mm23/krd/lambda_reduction/targetpos/tpos2.dat
Procedure • One W bin ( W~1.93 GeV ) • Three Q2 bins ( W~1.93 GeV ) • Two angular bins ( W~1.93 GeV ) • An original ROOT file • Add necessary information • Jacobian , HKS solid angle, K+ decay factor • Derive the QF background shape from 12C data • Subtract the background shape • Estimate virtual photon (flux) by a Geant4 simulation • Calculate the cross section with efficiencies and correction factors
12ΛB g.s. from CH2 target 52 (15) (4) nb/sr Polyethylene target 101 (4) (38) nb/sr in JLab E01-011
Paper of bucking coil to NIMA( final procedure ) http://dx.doi.org/10.1016/j.nima.2013.08.047