PowerPoint

HES-HKS analysis meetingToshiyuki Gogami10Jan2014

ContentsAbout missing mass resolutionBlind analysisResolution and linearity balanceResponse functionMissing mass statusBinding energy and cross section12B, 10Be and 7HeMissing mass estimation by the full-modeled Monte Carlo simulation

Achievable resolutionHyperon HypernucleusTarget [mg/cm2]IntrinsicMass offset due to energy lossMatrix z-dependence (B)Simulated total resolution (A)Achievable resolution (A-B)Present work(Toshis anlysis)CH2 (450)83010007302100138016007He7Li (184.0)440260550130075013009Li9Be(188.1)440260170740560Not yet10Be10B (56.1)430804059055080012B12C (87.5)4301308062054089052V52Cr (134.0)43016030630600Not yetPart of the z-dependence (, 0 and 12B) is absorbed by the matrices in a matrix tuning. Effects of z-dependence absorption for other hypernuclei are not trivial. Blind analysis( FWHM, Unit: keV )

Blind analysisWidth and linearity balanceMatrix z-dependence (,0) absorption effect for hypernucleiResponse functionFlow chartInitial matrices(not distorted)Tuned matricesTune, 0 and hypernucei, 0 and hypernuceiAbsorbing effects of z-dependenceAsymmetry shapeEtc.Compare after tuning

+ B.G.0 + B.G.12B s-shellGeneratedResults

FWHM [keV]MM [keV]Mean value displacementWidth, 0, 12B, 0, 0, 12B, 0MM < 130 keV500 ~ 700 keV (12B, 10B, 52V)~ 1000 keV (7He)~ 1500 keV (, 0) Achieved simultaneously ! + B.G.0 + B.G.12B s-shellNo matrix distortion+Achievable resolutionsResponse function

Missing mass status12C(e,eK+)12B7Li(e,eK+)7He10B(e,eK+)10Be

9Be(e,eK+)9Li52Cr(e,eK+)52V

12C(e,eK+)12B

7Li(e,eK+)7He

10B(e,eK+)10Be

9Be(e,eK+)9Li

Accidental background52Cr(e,eK+)52V

Binding energy and Cross sectionAbout cross sectionDefinitionCut conditionsEfficiencies and correction factorsResults12C(*,K+)12B7Li(*,K+)7He10B(*,K+)10Be

Definition of differential cross section

Number of virtual photonincluding HES acceptanceNumber of target protonsEfficienciesHKS acceptanceCut conditionsEfficiencies and correction factorsEfficienciesDAQTriggerTrackingK+ selectionAC, WC, m2, Correction factorsK+ decay (momentum dependent)Solid angle (momentum dependent)K+ absorption Event loss due to matrix and large energy loss (not included for the present work)Already studied by Fujita

~ 5- 10% 12C target

RemarksEfficiencies are different between low and high current dataTwo set of HES collimator positions are used. Differential cross section of 12C(*,K+)12B

Peak-B [MeV]Number of eventCross section [nb/sr]1-11.40 0.036572683 33-8.37 0.101351117 14-5.15 0.181181115 15-1.67 0.231161114 12-0.38 0.046312582 36+0.82 0.092401531 2Only statistical errors( FWHM ~ 0.89 MeV )12B comparisonExperiment-B [MeV]Cross section [nb/sr]E05-115-11.40 0.0383 3E01-011-11.40 0.01 0.04101 4.2 (+ 38 31)E89-009-11.52 0.35140 17 18Emulsion-11.37 0.06N/ASExperiment-B [MeV]Cross section [nb/sr]E05-115-0.38 0.0482 3E01-011-0.41 0.01 0.1394 4.0 35E89-009-0.49 0.16N/Ap7Li target

RemarksTarget thickness (Three values)Shichijo: 184.0 mg/cm2ELOGWeight and area: 331.2 mg/cm2Oil ? Nitriding ? Thickness and density: 207 mg/cm2

Nitriding testCheck Brems. Rate in HESEtc.Need to be done !!!!Differential cross section of 7Li(*,K+)7He

Peak-B [MeV]Number of eventCross section [nb/sr]1-5.28 0.144822212.4 0.52-3.50 0.14271167.0 0.4( FWHM ~ 1.3 MeV )7He comparison

(FWHM ~ 1.3 MeV)

-5.36 without CSB-5.16 with CSBPeak-B [MeV]Number of eventCross section [nb/sr]1-5.28 0.144822212.4 0.52-3.50 0.14271167.0 0.4( FWHM ~ 1.3 MeV )Hiyamas calc.10B target

Differential cross section of 10B(*,K+)10Be

Peak-B [MeV]Number of eventCross section [nb/sr]1-8.66 0.081411211.6 0.92-7.81 0.235174.3 0.73-6.08 0.091391211.8 1.04-5.03 0.147896.5 0.75-1.98 0.101561313.0 0.96-0.11 0.161231110.0 0.872.23 0.071881415.9 1.1811 .14 0.1394 107.8 0.8( FWHM ~ 0.8 MeV )Comparison with old data

MeVDifferential cross section of 10B(*,K+)10Be

Peak-B [MeV]Number of eventCross section [nb/sr]1-8.66 0.081411211.6 0.92-7.81 0.235174.3 0.73-6.08 0.091391211.8 1.04-5.03 0.147896.5 0.75-1.98 0.101561313.0 0.96-0.11 0.161231110.0 0.872.23 0.071881415.9 1.1811 .14 0.1394 107.8 0.8( FWHM ~ 0.8 MeV )

-8.84 without CSB-8.76 with CSBHiyamas calc.Motobas calc.9Be(*,K+)9Li (only figure)

SummaryEstimated missing mass resolutionBlind analysisResolution and linearity balanceResponse functionMissing mass statusBinding energy and cross section12B, 10Be and 7HeBackupExpected achievable missing mass resolutionZ-depenenceTuningz-dependence Resolution ? Linearity? Blind analysis (next)