HKS collaboration 2008/5/16 Wedding Party 2008/5/10

Topics Bug in REPLAY Blind analysis by Lulin

Bug in REPLAY

Multiplicity problem Run# 56089, eventID JLab ENGINE Tohoku ENGINE Ntuples are inconsistent  parameter files and source codes should be checked

Bug in analyzer Cut condition for ENGE momentum (depends on “default” matrix) Different “default” matrix between USA and Japan Bug depends on multiplicity of ENGE Event#1 Event#2 Event#3 (out of acceptance) Event#4 … Accept Reject

Old ntuple vs. New ntuple +12.1% +14.7% +17.5% +16.6% Fixed bug and re-analyze

Old RAP(12Jan08) vs. New RAP(04Apr08) TargetOld RAP [events] New RAP [events] Improve CH % 12C % 28Si % 7Li % Number of events …. Coin ntuple  Multiplicity (ENGE) RAP  Coincidence between HKS and ENGE

Blind analysis by Lulin

Simulation data for blind analysis Focal plane resolution in sigma 86  m (exf), 0.7 mrad (expfp), 210  m(eyf), 2.8 mrad (eypf) 110  m (hxf), 0.5 mrad (hxpfp), 110  m(hyf), 0.7 mrad (hypf) Fixed beam energy ( MeV) NO energy target # of event & S/N (Updated)  moderately (  : ~2150 counts,  : ~400 counts, 12  B g.s. :~600 counts) Sieve Slit data is ready Raster (0.25 cm × 0.25 cm) for CH 2

Lulin’s blind analysis Tune CH 2 & 12 C –Add peaks of 12 C one by one (maximum 6 peaks) Raster correction –only momentum of kaon Weight in the final step of tuning –1.0(  ), 1.0(  ), 5.0 (B.E.=11.43), 0.0(B.E.=13.63), 6.0(B.E.=16.70), 3.0(B.E.=20.35), 4.5(B.E.=23.04), 6.0(B.E.=23.70) Detailed will be shown in Lulin’s talk * In the following pictures …… GOD : answer of simulation Lulin-tune : result from Lulin’s tuning

Lulin-tune CH2(tuned event) Top : GOD. Bottom Lulin-tune RED : coin., BLACK : B.G. Top : GOD, Bottom : Lulin-tune for All event

Lulin-tune CH2 (NOT tuned background event) TOP : Lulin MM vs. GOD MM BOTTOM : wide region TOP : GOD MM BOTTOM : LulinMM

Each component (xpt,ypt,dp) Lulin vs. GOD expt eypt edp hxpt hypt hdp offset due to different central momentum

Lulin-tune C12(tuned event) Top : GOD. Bottom Lulin-tune RED : coin., BLACK : B.G. Top : GOD, Bottom : Lulin-tune for All event

Oka-tune C12 (NOT tuned background event) RED : coin., BLACK : B.G.

Binding energy & Yield Lulin analysisGOD Binding energy [MeV] Yield [counts] Contamination [%] Binding energy [MeV] Yield [counts] S/N (g.s.)~ (g.s.) ~54N/A 16.70~ ~ & 23.04~

How to estimate contamination Fit each peak by gaussian + offset Fitted counts : Integration of gaussian Real counts : # of real events in the peak(3  ) (simulation data can be identified) Contamination [%] = ((Fitted counts) – (Real counts)) / (Fitted counts) ×100

Contamination vs S/N ratio

Step by step missing mass Step 1 Initial matrix ( *.1110 ) Step 2 After involving  and  (*.02121) Step 3 After involving B.E.=11.43, 23.04, (*.03307) Step4 After involving B.E.=20.35 (*.03308) Step5 After involving B.E.=16.70 (*.04022)

Missing mass of step1(Initial) Top : CH2 for All event Bottom : Coin.(RED), B.G.(BLACK) Top : C12 for All event Bottom : Coin.(RED), B.G.(BLACK)

Missing mass of step2(tune ,  ) Top : CH2 for All event Bottom : Coin.(RED), B.G.(BLACK) Top : C12 for All event Bottom : Coin.(RED), B.G.(BLACK)

Missing mass of step3 (tune , ,2 major peaks) Top : CH2 for All event Bottom : Coin.(RED), B.G.(BLACK) Top : C12 for All event Bottom : Coin.(RED), B.G.(BLACK)

Missing mass of step4 (tune , ,2 major peaks, core#1) Top : CH2 for All event Bottom : Coin.(RED), B.G.(BLACK) Top : C12 for All event Bottom : Coin.(RED), B.G.(BLACK)

Missing mass of step5 (tune , ,2 major peaks, core#1,core#2) Top : CH2 for All event Bottom : Coin.(RED), B.G.(BLACK) Top : C12 for All event Bottom : Coin.(RED), B.G.(BLACK)

Summary The trend is the same as Okayasu’s result The linearity between reference masses (  and  ) seems OK but the outside is deformed Background contamination in 12 C peaks The background events that not used for tuning do not make peak Accuracy of binding energy : < 0.4 MeV

Comments on 7  He Okayasu Spectrum Lulin Spectrum Lulin Mass : MeV/c2 (atomic masses are used) Lulin Binging energy : MeV/c2 Okayasu Mass : MeV/c2 (nuclear masses are used) Okayasu Binging energy : MeV/c2 Lulin 7 He +  : MeV/c2 7 He +  : MeV/c2  = 0.46 MeV