Update 09.21.2018 -- Pythia: Fitting Pi0 and Gamma-Direct Spectra With Power Laws
As we move forward with the unfolding, we'd like to use a power law as a prior. So here are 4 spectra from Pythia fitted with power laws (that way we have a reasonable estimate of what the default parameters should be in the prior).
Here are the parameters organized into a table:
a | b | |
pi0 (9, 11) | 1.60 | 2.45 |
gamma (9, 11) | 1.74 | 3.04 |
pi0 (11, 15) | 1.59 | 2.23 |
gamma (11, 15) | 1.58 | 2.58 |
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To get a better fit, here're the same spectra fit over a smaller range: the pi0 spectra are fit over 'pTjet = 2 - 20' GeV/c and the gamma-direct spectra are fit over 'pTjet = 2' GeV/c to the upper limit of the trigger eT.
And in a table:
a | b | |
pi0 (9, 11) | 1.67 | 2.40 |
gamma (9, 11) | 1.74 | 2.65 |
pi0 (11, 15) | 1.48 | 2.11 |
gamma (11, 15) | 1.70 | 2.42 |
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To get an even better fit, I restricted the fit range further. Below I fit each spectrum with a power law over 'pTjet = 2' GeV/c to either the upper limit on the trigger 'pT' (for the pi0 case) or the lower limit on the trigger 'pT' (for the gamma-direct case).
And in a table:
a | b | |
pi0 (9, 11) | 1.48 | 2.30 |
gamma (9, 11) | 1.46 | 2.48 |
pi0 (11, 15) | 1.39 | 2.07 |
gamma (11, 15) | 1.24 | 2.14 |
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