How to get the FSU energy correction
Step 1. After applying ELoss-Correction (updated at Aug1210)
My decay mode is γ p -> p π+ π-.
I calculated the calculated photon energy,E(cal. γ) from the momentums of proton and pions after applying the eloss correction.
And then, I have found the difference between the calculated and measured photon energy in the following plots.
Step 2. After applying ELoss-Correction and Michael's Energy Correction
I applied the Michael's Energy Correction.
I have made the plots for the difference between the calculated and measured photon energy.
Butanol |
CH2 |
 |
 |
Step 3. Build up the FSU energy correction
After applyiing the Michael's energy correction, the difference and measured photon energy have a linear relation.
I have fitted them in butanol, carbon, and CH2 target. I had the parameter p0 and p1 from the fitting method.
If difference is positive, it mean E(cal. γ) > E(mea. γ). We need to add more in E(mea. γ) to have the zero difference.
If difference is negative, it mean E(cal. γ) < E(mea. γ). We need to subtract something in E(mea. γ).
Thus, the following equation is made.
|
Butanol |
CH2 |
Carbon |
p0 |
-0.02299 |
-0.01533 |
-0.01539 |
p1 |
0.0237 |
0.02012 |
0.02413 |
Step 4. After applying Sung's Energy Correction
The parameter p2 is worked to get the proper offset. After applying FSU energy correction, the difference is flat around zero.
By adding the parameter p2, you can shift up and down the difference.
Butanol |
CH2 |
 |
 |
