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Published byGavin Evans Modified over 9 years ago
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HES-HKS & KaoS meeting Toshiyuki Gogami 18Dec2013
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Missing mass Resolution Intrinsic mass resolution Production point displacement from the matrix origin Mass offset due to energy loss in target
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Intrinsic mass resolution Energy straggling, raster and mass offset are not included in these estimation Total resolution cannot be a simple quadratic sum since variables are not independent (but, simple quadratic sum is shown as an intrinsic resolution here) (but, simple quadratic sum is shown as an intrinsic resolution here)
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Production point displacement from the matrix origin (z-direction) 1.Effects are smaller (<0.1 MeV/c 2 ) for other targets since their thickness are less than 0.05 cm. 2.These effects are implicitly absorbed by matrices in a process of tuning (already checked in blind analysis)
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Energy loss correction (Before talking about mass offset) Target Most probable value for each particle Energy loss correction value Production at the center of target e e’ K+K+
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Energy loss correction (Before talking about mass offset) Target Most probable value for each particle Energy loss correction value Production at the center of target e e’ K+K+
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Mass offset due to energy loss ~ 0.7 MeV (hand calc. 0.67 MeV) z Most probable values Target
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In the case of 7 Λ He Others = 1.4 – 0.58 = 0.82 [ MeV ] Offset: 0.7 MeV, intrinsic: 0.4 MeV Sqrt(0.7*0.7 + 0.4*0.4) = 0.8 Matrix Matrix + MM offset + others
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Achievable resolution Simply subtracted matrix z dependence
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Blind analysis The first results
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Flow chart of blind analysis Compare Blind
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Flow chart of blind analysis 1.Imitation data generation 2.Distorted matrix generation 3.Tuning 4.Comparison tuned results with generated data
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The first sample Tune with Λ and Σ0 with realistic B.G. shape
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Missing mass Restarted tuning…. With new energy loss corrections for 12 C target 112.5 87.5 mg/cm 2 (ELOG)
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Carbon target 700 keV (FWHM)
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Lithium target 1000 keV (FWHM)
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720 keV (FWHM)
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Summary Resolution estimation Estimation will be improved soon Blind analysis The first results (delta B Λ < 100 keV) Matrix tuning restarted
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Backup
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Li target
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Target [mg/cm 2 ] Intrinsic (page 4) + Δm offset [MeV/c 2 ] Monte Carlo – (matrix z dep.) ΛCH 2 4501.9 7 Λ He 7 Li 184.01.1 10 Λ Be 10 B 56.10.65 12 Λ B 12 C 87.50.78 52 Λ V 52 Cr 154.00.88
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Production point displacement from the matrix origin (x-direction) x includes information of z because the target is tilted A pure effect from the x-dependence is compensated by the z-dependence Target z x
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Production point displacement from the matrix origin (y-direction) y-dependence
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Energy loss correction (Before talking about mass offset) Target Most probable value for each particle Energy loss correction value Production at the center of target e e’ K+K+
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Spectrometer resolution
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Mass offset where A, B and C are defined in page 4. Simply calculated by z Most probable values Target
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Mass offset where A, B and C are defined in page 4. Simply calculated by z Most probable values Target
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Want to understand simulated results (resolution)
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Energy loss correlation Bug fixed in POSI Expected correlation can be seen now.
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