Event Mixing Method as applied on GEN EC smeared events

NOTE! here 2.2 < Nu < 4.(instead of 4.25) and 1. < Q2 < 4. (instead of 4.1)

Method current and old photon are mixed into pi0 provided they belong to the same {Q2, Nu, z(pi0), pT2(pi0)} bins
Further old photon is rotated around Z on the angle d_Phi = gamma*(current)_Phi - gamma*(old)_Phi.
Compare shape of backgr fit and Npi0 reconstructed after backgr subtraction with Npi0 generated in diff phase-spaces.
Note : Photons of generated MC events are smeared in E and Position according to the known EC resolution

1. E_gamma > 0.15 GeV; 8 < Theta < 45 ; Angle(e,gamma) > 12
Fig.1a Number of generated pi0 in the above kinematic range in bins: Z pT2 Q2 Nu
Fig.1b Background shape from mixed events ifitted with Pol4 in bins: Z pT2 Q2 Nu
Fig.1c Inv Mass fitted with gaus+[par]*pol4; Ngaus = Npi0 in gaus; Npeak = N_tot - N_backgr. Z, pT2, Q2,Nu bins




Systematical errors
Number1 = (N_gen-N_calc)/N_gen +/- Number2 = absolute err on Number1; N_calc is (N from Gaus) || ( N in the peak = N_tot-N_back)
Average number and error on it are calcuated using for combing results (Number1+/-Number2) of independent measurements;

pT2(Gaus)0.70+/-0.02%, 1.30+/-0.02%, 0.95+/-0.02%, 1.06+/-0.02%, 1.47+/-0.02%, 2.00+/-0.03%, 1.65+/-0.03%, 0.93+/-0.02%, 0.73+/-0.02%
pT2(Peak)0.18+/-0.01%, 0.52+/-0.01%, 0.40+/-0.01%, 0.39+/-0.01%, 1.00+/-0.02%, 1.48+/-0.02%, 1.15+/-0.02%, 0.42+/-0.01%, 0.03+/-0.00%
average error over pT2 bins GAUS : 1.077 +/- 0.007 % Peak : 0.180 +/- 0.003

Z(Gaus) 4.72+/-0.04%, 1.73+/-0.02%, 0.23+/-0.01%, 0.17+/-0.01%, 0.92+/-0.02%, 1.22+/-0.03%, 1.06+/-0.02%, 0.96+/-0.02%, 0.68+/-0.02%
Z(Peak)4.31+/-0.04%, 1.18+/-0.02%, 0.74+/-0.02%, 1.23+/-0.02%, 0.03+/-0.00%, 0.64+/-0.02%, 0.63+/-0.02%, 0.41+/-0.01%, 0.04+/-0.00%
average error over Z bins: GAUS:0.536 +/- 0.005 % Peak : 0.152 +/- 0.003 %

Q2(Gaus)1.20+/-0.01%, 0.59+/-0.01%, 1.99+/-0.02%, 1.90+/-0.02%, 2.42+/-0.03%, 1.36+/-0.03%
Q2(Peak)0.71+/-0.01%, 0.02+/-0.00%, 1.55+/-0.02%, 1.46+/-0.02%, 1.97+/-0.03%, 0.88+/-0.02%
average error over Q2 bins: GAUS :1.177 +/- 0.007; Peak : 0.105 +/- 0.002 %

Nu(Gaus):1.38+/-0.01%, 1.54+/-0.02%, 1.64+/-0.02%, 1.13+/-0.02%, 1.34+/-0.03%, 1.28+/-0.03%
Nu(Peak) 0.94+/-0.01%, 0.98+/-0.01%, 1.11+/-0.02%, 0.69+/-0.02%, 0.90+/-0.02%, 0.75+/-0.02%
average error over Nu binsGAUS : 1.404 +/- 0.008 % ; Peak : 0.919 +/- 0.006 %


2. E_gamma > 0.3 GeV; 8 < Theta < 45 ; Angle(e,gamma) > 12
Fig.2a Number of generated pi0 in the above kinematic range in bins: Z pT2 Q2 Nu
Fig.2b Background shape from mixed events ifitted with Pol4 in bins: Z pT2 Q2 Nu
Fig.2c Inv Mass fitted with gaus+[par]*pol4; Ngaus = Npi0 in gaus; Npeak = N_tot - N_backgr. Z, pT2, Q2,Nu bins




Systematical errors
Number1 = (N_gen-N_calc)/N_gen +/- Number2 = absolute err on Number1; N_calc is (N from Gaus) || ( N in the peak = N_tot-N_back)
Average number and error on it are calcuated using for combing results (Number1+/-Number2) of independent measurements;

pT2(Gaus)1.69+/-0.05%, 0.51+/-0.02%, 0.32+/-0.02%, 0.07+/-0.01%, 0.24+/-0.01%, 1.01+/-0.02%, 0.91+/-0.02%, 0.51+/-0.01%, 0.50+/-0.02%
pT2(Peak)0.58+/-0.03%, 0.29+/-0.02%, 0.43+/-0.02%, 0.88+/-0.02%, 0.42+/-0.02%, 0.47+/-0.02%, 0.34+/-0.01%, 0.01+/-0.00%, 0.02+/-0.00%
average error over pT2 bins GAUS : 0.305 +/- 0.005 %; Peak : 0.049 +/- 0.002 %

Z(Gaus)4.27+/-0.05%, 1.48+/-0.03%, 0.27+/-0.01%, 0.52+/-0.02%, 0.35+/-0.02%, 0.29+/-0.01%, 0.37+/-0.02%, 0.63+/-0.02%, 0.53+/-0.02%
Z(Peak)3.51+/-0.05%, 0.92+/-0.02%, 1.00+/-0.02%, 1.38+/-0.03%, 0.59+/-0.02%, 0.33+/-0.02%, 0.16+/-0.01%, 0.04+/-0.00%, 0.09+/-0.01%
average error over Z bins: GAUS : 0.487 +/- 0.006 %; Peak : 0.170 +/- 0.003 %:

Q2(Gaus)0.26+/-0.01%, 0.31+/-0.01%, 1.28+/-0.02%, 1.09+/-0.02%, 1.52+/-0.03%, 90.09+/-0.12%
Q2(Peak)0.21+/-0.01%, 0.24+/-0.01%, 0.89+/-0.02%, 0.59+/-0.02%, 1.05+/-0.02%, 90.03+/-0.12%
average error over Q2 bins: GAUS : 0.692 +/- 0.006 % ; Peak : 0.519 +/- 0.005 %

Nu(Gaus):1.01+/-0.01%, 0.76+/-0.02%, 0.69+/-0.02%, 0.44+/-0.02%, 0.33+/-0.02%, 0.41+/-0.02%
Nu(Peak)0.68+/-0.01%, 0.16+/-0.01%, 0.10+/-0.01%, 0.17+/-0.01%, 0.18+/-0.01%, 0.40+/-0.02%
average error over Nu bins: GAUS : 0.656 +/- 0.007 % ; Peak : 0.215 +/- 0.004 %