HES-HKS analysis meeting

HES-HKS analysis meeting30 Aug 2013Toshiyuki Gogami

ContentsCross section of elementary processesIntroductionCorrection factorsK+ decay factor H reduction Results Bucking coilK+ , K+0 cross sectionsSAPHIR : 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)

(*) + p K+ + (*) + p K+ + 0Preliminary 200 16 91Preliminary 85 13 34

12B cross sectionHall-A

ele proscale

WQ dependence

3Angular and momentum acceptance

HESHKSW~1.93 GeVQ2KlabKCMDefinition of cross section

Solid angle of HKSEvent by eventThe number of VPIncluding HES solid angle and acceptanceThe number of electrons = 1.7545e185K+ decay factor

Hydrogen reduction correctionFigure: An photograph before and after the beam irradiation on the targets.

H reduction factor& Run selection76313 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

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 173.276351 172.276352 172.276353 172.276354 170.276355 170.276356 169.276357 169.276358 168.276359 168.276360 167.276361 167.276362 165.2

/data/8d/gogami/MM/mm23/krd/lambda_reduction/targetpos/tpos2.dat

Target position from EPICS

78.6 9.9 %ProcedureOne 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 informationJacobian , HKS solid angle, K+ decay factorDerive the QF background shape from 12C dataSubtract the background shapeEstimate virtual photon (flux) by a Geant4 simulationCalculate the cross section with efficiencies and correction factors

Resultslabe [rad]CMK [rad]Q2 [GeV/c]2 (CMS) [nb/sr]0 (CMS) [nb/sr]0.030-0.0500.270.003166 (17) (32)55 (29) (10)0.050-0.0700.260.007155 (18) (29)51 (30) (10)0.070-0.1000.270.013159 (18) (30)81 (29) (17)0.030-0.1000.270.007164 (10) (31)78 (17) (15)labe [rad]CMK [rad]Q2 [GeV/c]2 (CMS) [nb/sr]0 (CMS) [nb/sr]0.000-0.2500.200.007291 (32) (55)176 (12) (33)0.000-0.2500.350.007176(12) (33)53 (24) (10)0.000-0.2500.270.007198(12) (28)72 (20) (5)12B g.s. from CH2 target 52 (15) (4) nb/sr

Polyethylene target101 (4) (38) nb/sr in JLab E01-011Hidden factor, 2 ? Paper of bucking coil to NIMA( final procedure )http://dx.doi.org/10.1016/j.nima.2013.08.047

BackupEnergy lossK+ absorption factor

Trigger efficiency

Charge distribution

H reduction