Today's Progress 12. Feb. 2008

Cycle-by-cycle estimation of stopped K- number from K-μ2 decay peak

To finalize the normalization, we try to present cycle-by-cycle statistics of K-μ2 decay peak yield/stopped K- number here. The stopped K- number is derived by

and K-μ2 peak yield is applied to the normalization in the form,

DAQ related quantities

Here, we summarize DAQ-related quantities of every cycles. Tables are taken from the previous reports(E549/E570)

Summary Table of E549 Data Acquisition

Note that only the production runs are summarized for negative polarity. Due to the SCALER trouble, overall DAQ live time rate is calculated by run 25~200 for negative polarity, and DAQ duration for negative polarity is for that run region.
quantities/polarity +(run136~141) -(run25~306)
DAQ duration (min/hour/day) 330.4/5.51/0.23 (17575.7/292.93/12.21)
EP1 SEC 2935034 245179544
K5 SEC 2137044 171922841
K5 TM no data no data
Unbiased trigger number (beam originated) 8182157 (98666351)118913208
Accepted trigger number (beam originated) 5475571 (85464955)149359182
Overall DAQ live time rate(Accepted/Unbiased) 66.92 % (cf. E471 45.9%) (86.62 %) (cf. E471 90.6/91.6 %)
K beam counts 170.1 M (cf. E471 33.9M) 2177 M (cf. E471 896/806M)
Number of accepted/unbiased Kbeam/600 trigger 0.1730M/0.2835M : 61.02 % 3.134M/3.629M : 86.36 %
Number of accepted/unbiased Kstop-Charged trigger 2.579M/4.276M : 60.31 % 32.88M/38.22M : 86.03 %
Number of accepted/unbiased Kstop-VTC/10 trigger 2.752M/3.643M : 75.43 % 36.99M/41.83M : 88.43 %

Summary Table of E570 1st Cycle Data Acquisition

Note that K beam counts are not reliable, and all numerical values are derived from the value accumulated from run 86 up to 368, actually.
quantities/polarity +(run225~226) -(run31~368)
DAQ duration (min/hour/day) 182.8/3.0/0.13 27704.5/461.7/19.24
EP1 SEC 1608163 228817776
K5 SEC 1235935 177807397
Unbiased trigger number (beam originated) 4036882 368927500
Accepted trigger number (beam originated) 2878597 279234828
Overall DAQ live time rate(Accepted/Unbiased) 71.31% 75.69%
K beam logic counts 89.1M 1638.6M
Number of accepted/unbiased Kbeam/f trigger 1.153M/1.485M=77.62% 4.170M/5.481M=76.09%
Number of accepted/unbiased Kstop-Charged trigger 1.759M/2.595M=67.78% 34.71M/45.52M=76.26%
Number of accepted/unbiased Kstop-VTC-bar(VVC) trigger - 248.0M/326.2M=76.03%

Summary Table of E570 2nd Cycle Data Acquisition

Note that the values from run417/436 are eliminated from the statistics.
quantities/polarity +(run412~413) -(run417~583)
DAQ duration (min/hour/day) 199.9/3.3/0.14 15659.9/261.0/10.74
EP1 SEC 1703855 133066692
K5 SEC 1288348 99141884
Unbiased trigger number (beam originated) 4157218 184453664
Accepted trigger number (beam originated) 2922998 140068278
Overall DAQ live time rate(Accepted/Unbiased) 70.31% 75.94%
K beam logic counts 92.0M 1106.7M
Number of accepted/unbiased Kbeam/f trigger 1.162M/1.534M=75.74% 2.110M/2.767M=76.25%
Number of accepted/unbiased Kstop-Charged trigger 1.794M/2.666M=67.28% 16.66M/21.91M=76.03%
Number of accepted/unbiased Kstop-VTC-bar(VVC)trigger - 125.0M/164.5M=75.97%

Derivation of N-Kμ2 from delayed events

Here we try to derive N-Kμ2 by fitting the 1/β specra obtained with δT(T0->PA)>1.2 nsec, with third order polinomial BG+ three Gaussians (i.e. 13 free parameters).
Cycle-by-cycle arm-by-arm fit results, for δT(T0->PA)>1.2 (nsec).

Number of Kmu2 peak by δT(T0->PA)>1.2 nsec.
Arm/Cycle E549 E570-1 E570-2
L(counts) 56376 +- 28655986 +- 28222099 +-173
R(counts) 55262 +- 28155832 +- 29121997 +-172
Total(counts)111638 +- 401 111818 +- 405 44096 +- 244

Efficiency of Kstop ID

Here, we try to ε-stopK, by using delayed event. As the efficiency is independent to the δT(T0->PA), it is easily estimated by the relationship,

ε-stopK=NKμ2/N'Kμ2,

where NKμ2 is the number of peak area under KstopID>-1., and N'Kμ2 is the same number without applying KstopID>-1. As the ID function is just defined only with T0 energy and vertex z, the fraction is universally availale under the comparable z-resolution. The shape is neither affected by δT(T0->PA), nor the reaction occurs after the stopping.
KstopID function when a PA-PD-PDC set is fired. Top:all / Bottom:&delta:T(T0->PA)>1.2 (nsec)
Comparison of 1/β spectra of all(black)/KstopID>-1.(red)/KstopID<-1.(green), for &delta:T(T0->PA)>1.2 (nsec).

The fit results are tabulatted below.

Number of Kmu2 peak by δT(T0->PA)>1.2 nsec without KstopID>-1, and ε-stopK
Arm/Cycle E549 E570-1 E570-2
L(counts)/ε-stopK 62240 +- 314 / 90.6%61220 +- 302 /91.5% 23811 +- 183/92.8%
R(counts)/ε-stopK 61231 +- 302 / 90.3%61445 +- 306 /90.9% 23732 +- 183/92.7%
Total(counts)/ε-stopK123471+- 436 / 90.4%122665 +- 430 /91.2% 47543 +- 259/92.7%

Cycle-by-cycle statistics of stopped K- number

The stopped K- number is defined as follows:

NstopK-=N-Kμ2/(P-*Br*ε-&mu*ε-DAQ*ε-BLC*ε-PDC*ε-TRG*ε-stopK*ε-delay).

Considering ε-BLC=ε-PDC=1, and assuming ε-TRG=1, the expression is reduced into

NstopK-=N-Kμ2/(P-*Br*ε-&mu*ε-DAQ*ε-stopK*ε-delay).

Substituting P-=0.035 +- 0.005, Br=0.6351, &epsilon-μ=0.0755, and &epsilon-delay=exp(-1.2/10.4), we obtain the following values for NstopK-.

Number of stopped K-
Arm/Cycle E549 E570-1 E570-2
N-stopK / N-stopK/spill 95.3 M / - 108.3 M / 260.6 41.9 M / 178.4