HES-HKS & KaoS meeting 30July2013 Toshi Gogami

Contents Λ の減少 (H の減少 )

Data of Doi’s thesis Modified by Toshi 8Mar2013

Charge’ dependence The number of Lambda The number of QF Charge’ [ uC ] Coincidence time ( w/o Λ,Σ 0 from H ) (True+Acc.) – (Acc 6.)/6.0 Time or charge dependence should be seen to see a tendency of reduction of number Λ ( Σ 0 ).  EPICS 15Mar2013

CH x target CH 1.61 CH 1.93 CH June2012

Target position from EPICS Raster pattern 1.6 x mm x 4.9 y mm

Event selection for the estimation Used for QF and accidental events (7 ~ 70 MeV) Used for Lambda (-2 ~ 4 MeV)

Used for QF and accidental events (7 ~ 70 MeV) Used for Lambda (-2 ~ 4 MeV) Λ : QF : Acc. : QF : Acc. : Event selection for the estimation

Definition of a variable, “charge”

Event reductions Reduce QF Λ from 12 C Accidental coincidence Λ from H + QF Λ from 12 C + Accidental Coincidence

Event Reduction (results)

Event Reduction (speculation) 1.Run selection 2.Charge calculation 変えたこと Reduction of 12 C target due to expansion ? Smaller value caused by wrong run selection Consistent with the C/H measurement 60um

Summary – Λ reduction Consistent with the H/C measurement Outlook – Elementary cross sections – Matrix tuning – NIM-A

Backup

Reduction4.dat [0]+((([1]*x)-([2]+(([3]*x)-([4]+([5]*x)))))-([6]+([7]*x))) After6000uC: After3000uC: ERRORat0(value,percent): This data file was created by ~/MM/mm23/krd/lambda_reduction/root/reduction4.cc Toshi Gogami, 30July2013

HES-HKS & KaoS meeting Toshi Gogami 15Mar2013

Doctor thesis for JLab E Electroproduction of Kaons on Hydrogen and Deuterium (Douglas Michael Koltenuk, 1999) 8

Charge’ Accidental + True Coincidence time [ns] (CHARGE) end / ( EVENT ID ) max * ( EVENT ID ) Charge’ [ uC ]  Scaled EVENT ID

Charge’ dependence The number of Lambda The number of QF Charge’ [ uC ] Coincidence time ( w/o Λ,Σ 0 from H ) (True+Acc.) – (Acc 6.)/6.0 Time or charge dependence should be seen to see a tendency of reduction of number Λ ( Σ 0 ).  EPICS

Cross section Lambda Polyethylene – Burning out effect (Time dependence) Time dependence (Charge ) by using EPICS information Water – Trigger Efficiency ( Cherenkov ) No CP0 data cannot be used for estimation for this target Rate ( multiplicity ) vs. efficiency  Extrapolate

12 Λ B peak differences of s,p-shell Energy loss Beam angle Carbon Polyethylene