HLAB meeting

Status report4Mar2014

Toshiyuki Gogami

Experimental setup

Data summary

Experimental setup

Data summary

Definition of differential cross section

Number of virtual photonincluding HES acceptance

Number of target protons EfficienciesHKS acceptance

Efficiencies and correction factors• Efficiencies• DAQ• Trigger• Tracking• K+ selection

• AC, WC, m2,

• Correction factors• K+ decay (momentum dependent)• Solid angle (momentum dependent)• K+ absorption • Event loss due to matrix and energy loss

• Small effect for hypernucelus systematic errors• Acceptance (real and simulation)

• Small discrepancy systematic errorSystematic error click here

Systematic error for cross-section

Systematic error for binding energy

With Initial matrices With tuned matrices

SIMULATION

SIMULATIONIn progress

12C(e,e’K+)12ΛB spectrum

Count Cross sectionVirtual photon fluxEfficienciesAcceptance

Λ binding energy for 12C(e,e’K+)12ΛB

Peak - BΛ [MeV] N [nb/sr]1 -11.380.02 76528 97.83.611.52 -8.390.05 14912 19.01.52.23 -5.200.09 13511 17.21.42.04 -1.700.07 9410 12.01.31.45 -0.430.03 65826 84.13.39.96 0.470.06 21014 26.81.73.2

(FWHM: 500 keV)

12ΛB comparison

Experiment

θγKLab [degree] -BΛ [MeV] Cross section [nb/sr] Extracted value from

Motoba-san’s predictionE05-115 6.8 -11.38 ± 0.02 ± sys. error 97.8 ± 3.6 ± 11.5 75

E01-011 5.8 -11.40 ± 0.01 ± 0.04 101 ± 4.2 (+ 38 – 31) 85

E89-009 0 -11.52 ± 0.35 140 ± 17 ± 18 120

Emulsion -11.37 ± 0.06 N/A

SΛ

Experiment

θγKLab [degree] -BΛ [MeV] Cross section [nb/sr] Extracted value from

Motoba-san’s prediction

E05-115 6.8 -0.43 ± 0.03 ± sys. error 84.1 ± 3.3 ± 9.9 85

E01-011 5.8 -0.41 ± 0.01 ± 0.13 94 ± 4.0 ±35 96

E89-009 -0.49 ± 0.16 N/A

pΛ

7Li(e,e’K+)7ΛHe spectrum

Count Cross sectionVirtual photon fluxEfficienciesAcceptance

Λ binding energy for 7Li(e,e’K+)7ΛHe

E01-011: -5.680.030.25 MeV

Peak - BΛ [MeV] N [nb/sr]1 -5.740.10 45021 17.30.82.82 -3.840.16 38220 14.70.82.4

(FWHM: 1300 keV)

-5.36 without CSB-5.16 with CSBHiyama’s calc.

Λ binding energy for 7Li(e,e’K+)7ΛHe

E01-011: -5.680.030.25 MeV

(FWHM: 1300 keV)

-5.36 without CSB-5.16 with CSBHiyama’s calc.

Peak - BΛ [MeV] N [nb/sr]

1 -5.740.10 45021 17.30.82.8

2 -3.840.16 38220 14.70.82.4

About Lithium target thickness

ELOG Entry: 185809Lithium 7 (325.2mg, 0.982cm2 331.2mg/cm2)Thickness of Lithium is 3.9mm, using density of 0.535g/cm3, it is 207mg/cm2.

For energy lossFor cross-section

A photograph before mounting already black….. Nitride ? Lithium nitridation test will be done.

窒化テスト

窒化テストします電子天秤 環境ロガー

END

Backup

Gaussian fitting

Gaussian fit 8020 events (/10000)

~80% counting efficiency

SIMULATION (after matrix tuning)12C, 87.5 mg/cm2

12ΛB (-BΛ=-11.37 MeV)

[GeV]

[ Cou

nts

/ 100

keV

]

Contribution to missing mass resolution

One of results of blind analyses

Missing masses with initial matrices

Simply calculated by quadratic sum