1. HES-HKS & KaoS meeting 30July2013 Toshi Gogami

2. Contents Λ の減少 (H の減少 )

3. Data of Doi’s thesis Modified by Toshi 8Mar2013

4. 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

5. CH x target CH 1.61 CH 1.93 CH 1.96 13June2012

6. Target position from EPICS 76363 165.2 76365 163.2 76366 163.2 76367 161.2 76368 161.2 76369 159.2 76370 159.2 76371 157.2 76372 157.2 76373 155.2 76374 153.2 76375 153.2 76376 151.2 76377 151.2 76378 149.2 76564 148.74 76565 148.74 76566 148.74 76567 147.74 76568 147.74 76569 146.74 76570 146.74 76571 145.74 76338 185.2 76339 185.2 76340 185.2 76341 176.2 76342 176.2 76343 175.2 76344 175.2 76346 175.2 76347 174.2 76348 174.2 76349 173.2 76350 173.2 76351 172.2 76352 172.2 76353 172.2 76354 170.2 76355 170.2 76356 169.2 76357 169.2 76358 168.2 76359 168.2 76360 167.2 76361 167.2 76362 165.2 76313 136.74 76314 136.74 76315 136.74 76316 138.74 76317 138.74 76318 140.74 76319 140.74 76320 142.74 76321 142.74 76322 186.2 76323 186.2 76324 186.2 76326 185.2 76327 185.2 76328 185.2 76329 185.2 76330 185.2 76331 185.2 76332 185.2 76333 185.2 76334 185.2 76335 185.2 76336 185.2 76337 185.2 76572 145.74 76573 144.74 76574 144.74 Raster pattern 1.6 x mm x 4.9 y mm

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

8. Used for QF and accidental events (7 ~ 70 MeV) Used for Lambda (-2 ~ 4 MeV) Λ : 1278 +- 46 QF : 332 +- 24 Acc. : 137 +- 11 QF : 3175 +- 75 Acc. : 1291 +- 35 Event selection for the estimation

9. Definition of a variable, “charge”

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

11. Event Reduction (results)

12. 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

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

14. Backup

15. Reduction4.dat [0]+((([1]*x)-([2]+(([3]*x)-([4]+([5]*x)))))-([6]+([7]*x))) 8 1944.07 90.2165 -0.0656888 0.0273167 480.522 0 -0.00384072 0 137.799 0 -0.000266326 0 137.799 1.64719 -0.000266326 0.000509348 After6000uC: 0 0.797264 1 0.746445 2 0.952043 3 0.988404 After3000uC: 0 0.898632 1 0.873223 2 0.976022 3 0.994202 ERRORat0(value,percent): 90.2316 3.34177 This data file was created by ~/MM/mm23/krd/lambda_reduction/root/reduction4.cc Toshi Gogami, 30July2013

16. HES-HKS & KaoS meeting Toshi Gogami 15Mar2013

17. Doctor thesis for JLab E91-016 Electroproduction of Kaons on Hydrogen and Deuterium (Douglas Michael Koltenuk, 1999) https://misportal.jlab.org/ul/publications/view_pub.cfm?pub_id=539 8

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

19. 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

20. 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

21. 12 Λ B peak differences of s,p-shell Energy loss Beam angle Carbon Polyethylene