HES HKS meeting15 Nov 2010

T.Gogami

E05-115 experimental setup in JLab Hall C (2009)

Content

• e , e+ rejection in h_tof_pre.f• POSI– Electron rate

• Moller

e , e’ backgroundReject e,e+ in h_tof_pre.f

REAL DATA

h_tof_pre.f

NO CHANGE FOR• OPTICS• K+

File size and analysis time 7Li 52Cr CH2 H2O

File before[MB]

12.0 1.6 9.6 2.6

File after[MB]

9.3 0.7 7.0 1.4

Time before/100000

4:06 5:29 3:16 5:16

Time after/100000

4:41 4:51 2:51 4:49

File size 46% ~ 78 %Time 90%

Number Reconstruction with POSI

~ 4 [MHz] HES single

Theta vs. Phi cutSIMULATION

• HES• EDCTrig• EYQ1i > -4.7 [cm]

Chromium target

• POSI• Electron flag

Electron Rates

Events : 92/(2G)

2.3 ± 0.24 [MHz] at 7.9 [μA]

~ OK

700 – 988 [MeV/c]

1. Electrons which are not on optics.2. Simulation is loose

SIMULATION

Added new leaves ( POSI )

• Electron– Beam Passing through– Ionization– Brems.

• Photon– Compton scattering– Photoelectric effect– Photon conversion

SIMULATION

Cross section of Moller scattering

CALCULATION

Summary and to do• Summary– e , e+ rejection in h_tof_pre.f– POSI

• Electron rate– Moller

• to do– Analysis

• Residual of chambers for each arm.• HES tracking

– Strangeness 2010 in KEK• Preparation

– タイヤ交換

End