HKS Analysis Report

1
HKS Analysis Report

1. Kaon PID
2. Cross Section of QF Kaon

Tohoku Univ.
2
Define the production cross section of K

• Nob Number of Kaon
• Nvp Number of Virtual Photon
• ?Calculate Enge Acceptance with MC
  simulation
• Ntar Number of Nuclei ? Target thickness,
  density
• eHKS HKS data taking efficiency
• eEngeEnge data taking efficiency
• ecutOffline Analysis efficiency

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Survival Rate in AC, WC
(12C target?Current 26uA)
normalized
kaon Surv. Rate 70 pion Surv. Rate lt 4
kaon Surv. Rate 90 proton Surv. Rate 50
4
ß cut
w/o AC, WC cut
K
p
w/ AC, WC cut fit w/ gaussianpol(2) function s
of Kaon gaussian 0.02 selected -0.05, 0.05
(2.5s)
p
Integrate gaussian
Num. of Kaon
0.05
ß-ßK
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VP Flux and its integration
Total VP Yield ? Integration of G(O,?)
represent the Acceptance of Spectrometer
(Integrated) VP Flux (unit NoVP/NoE)
Independent on the target and beam intensity
Ntotal ? depend on the target and beam intensity
VP Rate NoVP/sec
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VP Flux _at_ E01-011
Assumption 100mg/cm2 12C target, 20uA beam,
s?100 nb/sr HKS Solid Angle
0.015 rad , Kaon Decay Rate 0.3
VP Flux NoVP/NoE VP Rate NoVP/sec/sr 12?B g.s Ratio g.s./hr
Rough Estimation 0.2010-4 1.2 19
Geant3 Simulation 0.3510-5 0.22 3.6
Measured Value - - 7-8 ?
Conditions on Rough Estimation
-120ltxlt120mrad, 70ltylt90mrad,
p300MeV, dp30
inconsistent
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Target Dependence of Cross Section
seems to be good
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How about the Differential Cross Section ?
Case 12C Target
eHKS0.326(Kaon decay rate), eEnge100,
ecut70 Ntar 5.101021 Nob 2.30104(w/
acc.)7.9(w/ coin.)1.82103 Nvp
2.5010183.5010-6NoVP/1electron8.781012
data
MC simulation by Akihiko
s1.7810-1 µb
ds/dO 11.9 µb/sr
divide by HKS acc. (0.015sr)
too large!
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Summary Things to do

• Im trying to get the the production cross
  section of QF Kaon.
• VP calculation is not easy in this case (Akihiko
  will give a detained report ).
• I must get the efficiency of HKS counters
  (detection efficiency, tracking efficiency).
• Get the Differential Cross Section for QF Kaon.

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About VP Flux
The definition of VP Flux (G)
(e,eK) reaction
VP absorption Cross Section
(e,eK) diff. Cross Section O, ? Angle and
Momentum of e
G Formula
Reference
T.DEForest, Jr and J.D.Walecka, Electron
Scattering and Nuclear Structure, Advances In
Physics 15 (1966) 1.