Pi0 Simulation for BigCal Jixie Zhang June 10, 2015

What Is New? https://github.com/jixie/sane_geant3_mc 1. In previous analysis, the weighting of event from various targets (H,He,N,Al) were not considered. The weighting and luminosity calculation were therefore wrong. 2. Total new analysis code. 3. In this analysis, new weighting method is applied. 4. Define pi0 signal as any single that pass electron cut which include Chrencov window cut. Therefore what I show in this talk is background from pi0, not just the positron.

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 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 0.00381 x 2 2.7 26.982 0.000763 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. This table shows the relative relation among materials in the target cell. If normalized to N14, the result is: H : He : N : Al = 3 : 0.923 : 1 : 0.00884

How to Do The Normalization 1) Fill four 3-D histograms of E:CosTh:phi with cross section of H, He, N and Al. 2) Sum these four 3-D histograms, weighted by the number of atoms in the target. Integrate the result 3-D histogram to get total cross section, XS 3) Count number of thrown events in the simulated ntuple, N, each thrown event is weighted by the number of atoms in the target. 4) Charge is proportional to N/XS 5) The yield from BigCal after all cuts will be scaled by Charge . electron: threw 15M events, TotalXS=190.641 N_Throw=1.37601e+07 N_Detected=1.2441e+07 fScale=13.8546 pi0: threw 15M events, TotalXS=49.0141 N_Throw=1.47105e+07 N_Detected=1.04723e+07 fScale=3.33191

How to Do The Normalization 1) Fill four 3-D histograms of E:CosTh:phi with cross section of H, He, N and Al. 2) Sum these four 3-D histograms, weighted by the number of atoms in the target. Integrate the result 3-D histogram to get total cross section, XS 3) Count number of thrown events in the simulated ntuple, N, each thrown event is weighted by the number of atoms in the target. 4) Charge is proportional to N/XS 5) The yield from BigCal after all cuts will be scaled by Charge .

Definition of Electron 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 number of photon electron E_m is the energy deposited in the BigCal

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)

Example electron

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