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Normalization p-Be 40 GeV (2001 data)
Running periods Stability - S4/S3, Flux - Cbeam/Beam - CBeamDt/Beamdt Proton fraction - CerOr/S3 - CBCerOr/Cbeam Burst Structure Conclusion NA57 meeting June 2003 RL+OVB
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Running Periods Three running periods: From beginning until 10.8,
1.4*10^7 good events S3, S4, ST2, SPH11T, SPH12T, SPH21T, SPH22T, Beam, BeamDT, INT, INTDT, TelInt1T, TelInt2T, CU1, Cer1, Cer2, CerOR From 10.8., 5.9*10^7 good events Cbeam, CBeamDt From 28.8., 2.7*10^7 good events CBCer1, CBCer2, CBCAND, CBCOR
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S4/S3 vs RUN
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Normalization Yield = weight / N N - number of interactions
N =(1- exp(L/)*Flux* Fract(proton) L - target thickness - p Be interaction length Beam DT Flux = CBeamDT 1 – CER1ORCER2/S3 Fract(prot)= 1 - CBCEROR/CBEAM Two broblems: Cbeam not available for allthe run CBeamDT/Beamdt > 1
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Cbeam/Beam vs RUN
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Cbeam/Beam Spill length = 5.2 s, <S3> 10^7
Cbeam condition: no S3 in 45 ns before and after Cbeam CB P(CB) = P(Beam)*(exp(-45/520)^2 CB/Beam= 0.84 Electronic can not recognize S3 closer then 20-30 ns: CB/Beam exp(-35/520)^2= 0.87 Correction for flux 4.7 % exp(-35/520)= 0.953
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BeamDT vs CBeamDT Problem: CBeamDT/BeamDT > 1
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Double Ratio Check (CBeamDT/Cbeam)/(BeamDT/Beam)
Stable and < 1 all the time ! Correct CbeamDT = Cbeam* (BeamDT/Beam)
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Черенков (CerOr vs CBCerOr)
1 – CER1ORCER2/S3 Fract(prot)= 1 - CBCEROR/CBEAM <CER1ORCER2/S3> 0.85 < CBCEROR/CBEAM> 0.7 Two effects: beam misses S3 (dominant) Run (logbook) S3.COR/S3 0.78 Run (end of burst) COR/S3 0.89 Cbeam protection – light from subsequent events close in time can influence all of them
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(CerOr/S3)/(CBCerOr/Cb)
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S3.CerOr/S3
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Cerenkovs – infinite time resolution
A) Ideal case: CerOr = S3*0.7 CBCerOR =CB*0.7 CU1 = a*0.3*CB B) 45ns gate - pion kills everything in 45 ns: CerOr = S3*( *2*(1-exp(-45*0.7/520))= = S3*( ) CU1 depends on period: If Cbeam in trigger: CU1=a*CB*0.3 If Beam in trigger: CU1= a*CB*0.3*(exp(-45*0.7/520))^2 = = a*CB*0.3*0.886
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Cerenkovs – 25 ns resolution
C) No 45 ns gate: CerOr = S3*( *(1- exp(-25*0.7/520))= = S3*( ) CBCerOR =CB*( ) CU1 = a*0.3*CB* exp(-25*0.7/520) = = a*0.3*CB*0.967 D) 45 ns gate - pion kills everything in 45 ns: CerOr = S3*( *2*(1-exp(-45*0.7/520))= = S3*( ) (as B) CBCerOR =CB*( ) (as C) CU1 depends on period: If Cbeam in trigger: CU1=a*CB*0.3*0.967 (as C) If Beam in trigger: CU1= a*Beam*0.3*exp(-45*0.7/520)^2 = = a*CB*0.3* (as B)
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Factors in Cerenkovs CBCerOR/CB = p(π)+0.01 CerOr/S3 = g*(p(π)+0.036)
g – geometry factor CerOr/S3 = g*(CBCerOr/CB ) g = CerOr/S3/(CBCerOr/CB+0.026) p(π) = CerOr/S3 * <(CBCerOr/CB+0.026)/(CerOr/S3)>-0.036 CerOr/S3 * <(CBCerOr/CB)/(CerOr/S3)> Last two factors cancel.
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Correction factor I. Period: Beam in CU1 and CerOR
Flux = BeamDT*1.05*0.886 Proton Fraction = 1 – CerOr/S3*0.86 1.05=1/Prob(0 events after Beam in 25 ns) 0.886=factor for CU1 (see previous page) 0.86 = <(CBCerOR/CB)/(CerOR/S3)> II. Period Cbeam in CU1 and CerOr Flux = BeamDT*(Cbeam/Beam)*1.05 Proton Fraction = 1- CerOr/S3*0.86 III. Period: Cbeam in CU1 and CBeamCerOr Flux = BeamDT*(Cbeam/Beam)*1.05 Proton Fraction = = 1 – (CBeamCerOR/Cbeam )
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Burst structure Run 17100 – event scalers info extracted
- S4/S3 versus event in burst distribution of number of CbeamDT between Subsequent CU1 plotted – should be P( r ) = lambda/(1+lambda)^(r+1) Lambda = cu1/cbeamDT
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S4/S3 vs time in burst
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Distribution of CBeamDT
Frequency # of CBDT between two subsequent CU1 P( r ) = lambda/(1+lambda)^(r+1) Lambda = cu1/cbeamDT No free parameters !
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Next Trigger inspection in NA57 Burst structure Distributions in run
Factors run by run
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Introduction End of Burst records extracted from raw data by Jozef Urban only for 2Track according to Ivan’s list average values of scalers per run calculated GOOD RUNS found checking scalers ratios and other sources Target SPH2 S S SPH ST V0 50x x8
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