Currently, the repository contains 2 analyses that are based on real data:
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Unpolarized photoproduction of pi+ pi- (
momentsPhotoProdPiPiUnpol.py): Unpolarized moments of the$\pi^+ \pi^-$ final state are calculated from GlueX low-energy data in the mass range from 0.4 to 1.4 GeV and compared to results from a CLAS analysis. -
Polarized photoproduction of pi+ pi- (
momentsPhotoProdEtaPi0.py): Moments for linearly polarized photoproduction of the$\eta \pi^0$ final state are calculated from real data and compared to the moments calculated from the partial-wave amplitudes obtained from a PWA fit to data.
There are three test cases with contrived acceptance:
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Diffractive scattering (
testMomentsDiffractive.py): For this process, the intensity distribution is a function of the decay angles$\Omega = (\theta, \phi)$ of one of the daughters particles and is described by a set of moments$H(L, M)$ . -
Photoproduction with linearly polarized photon beam (
testMomentsPhotoProd.py): For this process, the intensity distribution is a function of$\Omega$ and of the azimuthal angle$\Phi$ of the beam-photon polarization with respect to the production plane. The intensity is described by three sets of moments$H_{0, 1, 2}(L, M)$ . -
Photoproduction with linearly polarized photon beam and sideband subtraction (
testMomentsPhotoProdWeighted.py): In addition to the signal sample that is identical to the above case, a background sample is added that has a different angular distribution and is subtracted using side bands in a contrived discriminating variable. The signal follows a Gaussian in the discriminating variable, whereas the background is uniformly distributed.
There are two test cases with realistic GlueX acceptance:
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Polarized photoproduction of rho (
testMomentsPhotoProdRho.py): Moments for linearly polarized photoproduction of$\rho(770)$ are extracted from signal Monte Carlo data generated using the assumptions of natural-parity exchange and s-channel helicity conservation. No background subtraction is performed. No event weighting is performed; background from RF sidebands is removed using Chi^2-ranking approach. -
Polarized photoproduction of eta pi0 (
testMomentsPhotoProdEtaPi0.py): Moments for linearly polarized photoproduction of the$\eta \pi^0$ final state are calculated from partial-wave amplitudes. The amplitudes were obtained by performing a partial-wave analysis of signal Monte Carlo data generated using model with 7 partial waves, where the$S_0^-$ and$S_0^+$ waves contain a Breit-Wigner amplitude for the$a_0(980)$ and the$D_{-1, 0, +1}^-$ and$D_{-2, +2}^+$ waves contain a Breit-Wigner amplitude for the$a_2(1320)$ . No background was simulated. Event weighting is performed to remove background from RF sidebands.