Pi0 Simulation for BigCal Jixie Zhang July 2nd, 2015

What Is New? https://github.com/jixie/sane_geant3_mc 1. The weighting of event from various targets (H,He,N,Al) were calculated according to the numbers listed in the wiki, aluminum including target nose and 4k-shielding. 2. Weight thrown events to match the cross section in 3-D space of p:cosq:phi. 3. Checked the weighting carefully. 4. Due to statistics reason, rebin the RCS and Protvino calorimeter by 2x2.

Definition of Electron Cut In the geant3 simulated ntuple, an electron is defined as the following: A) cer_npe > 60 && cer_npe < 110 B) E_m > 0.5 cer_npe is the number of photon electron E_m is the energy deposited in the BigCal

About Thrown Events

Number of Atoms in The Target Nose Material Z Thickness (cm) Density (g/cm^3) Moll-Mass (g/moll) Number of Atoms Al end caps 14 0.0065x2.54 x 2 2.7 26.982 0.0033042 H 1 1.8 NH3=0.817 NH3=17.0304 0.086351 x 3 N 7 0.086351 LHe 2 1.2+0.5+0.5 0.145 4.003 0.07969 A) 60% packing fraction, B) target cell length is 3 cm, C) the liquid helium thickness outside the cell is 0.5 cm on both ends, D) Aluminum include 2 end caps(1.5 mil), 4k-shielding (1 mil) and target nose (4mil). This table shows the relative relation among materials in the target cell. If normalized to N14, the result is: H : He : N : Al = 3 : 0.9229 : 1 : 0.0383

Weight Thrown Events to Match Cross Section Shape 1) Fill four 3-D histograms, H3XS, of E:CosTh:phi, the content in each 3-D grid is the averaged cross section of H, He, N and Al. 2) Sum these four 3-D histograms, weighted by the number of atoms in the target to get H3XS_total. Integrate the resulting 3-D histogram to get total cross section, XS_total. 3) Fill four 3-D histograms, H3N, of E:CosTh:phi, weighted by the number of atoms in the target. Add them together to get H3N_total. The integral of H3N_total, N_total, is the total number of thrown events. 4) Scale H3XS_total such that its integral equal to that of H3N_total, then H3Weight=H3XS_total/H3N_total. This weighting will match thrown events into the shape of cross section. Later on, use H3Weight to weight each event in the analysis. 5) Charge is proportional to N_total/XS_total. The yield from BigCal after all cuts will be scaled by Charge .

Log file Electron runs: 22 M events TotalXS_All = 0.0561277 TotalXS_H = 0.0027661 weight_H = 3 TotalXS_He = 0.0102431 weight_He = 0.922859 TotalXS_N = 0.035752 weight_N = 1 TotalXS_Al = 0.0685864 weight_Al = 0.0382646 _e: TotalXS=0.0561277 N_Thrown=2.60679e+07 fChargeScale=0.0107657 TYPE N_thrown N_bigcal N_bigcal_cut N_e+_or_e- N_e+ Count_0 22000000 20535839 19906524 6551984 89941 Count_w 2.60679e+07 2.43311e+07 2.35755e+07 7.75708e+06 103115 Yield 2.59097e+07 2.39149e+07 2.33665e+07 5.05518e+06 20199.2 Count_w/Yield 1.00611 1.0174 1.00895 1.53448 5.1049 Pi0 runs: 61M events TotalXS_All = 44.8795 TotalXS_H = 2.06561 weight_H = 3 TotalXS_He = 8.26141 weight_He = 0.922859 TotalXS_N = 28.9243 weight_N = 1 TotalXS_Al = 55.7765 weight_Al = 0.0382646 _pi0: TotalXS=44.8795 N_Thrown=7.56646e+07 fChargeScale=2.96569 TYPE N_thrown N_bigcal N_bigcal_cut N_e+_or_e- N_e+ Count_0 61000000 50225082 43422010 983148 502383 Count_w 7.56646e+07 6.23102e+07 5.38675e+07 1.22072e+06 623682 Yield 7.52866e+07 6.13328e+07 4.30758e+07 242527 126857 Count_w/Yield 1.00502 1.01593 1.25053 5.03332 4.91643

BigCal RCS: 24 rows x 30 (columns) Y=0 at geant3 code Protvino: 32 rows x 32 (columns) different colors indicating the groupings of the trigger channels

Binned by groups of blocks Coded by 2-digit row index and 2-digit column index. i.e. This is 0103 0300 0200 Y=0 at geant3 code 0100 0000 Protvino: 32 rows x 32 (columns) Grouped by: 8(rows) x 8 (columns) RCS: 24 rows x 30 (columns) Grouped by: 6(rows) x 6 (columns)

PROT Yield for Electron

PROT Yield for Pi0

RCS Yield for Electron

RCS Yield for Pi0

PROT Yield Ratio: Pi0 to Electron

RCS Yield Ratio: Pi0 to Electron

RCS Yield Ratio: Pi0 to Electron

PROT Pi0 Fraction: Pi0 to Total

RCS Pi0 Fraction: Pi0 to Total

PROT Yield for Electron

BigCal Yield Ratio: Pi0 to Electron

BigCal Pi0 Fraction: Pi0 to Total