S3: Milestones second funding period

  • Measurements of the observables σ0, T, F, E, G for reactions γp → pπ0, γp → pη, γp → pη' at MAMI and ELSA will be fully analyzed. Together with new data from JLab a data set with unprecedented precision and completeness will be available.
  • A single-energy PWA using analytical constraints will be performed of all reactions mentioned above. The obtained amplitudes will be analyzed with the L+P expansion method in order to identify resonance contributions, to obtain pole parameters, and to search for new resonances. The π-MAID, η-MAID and η'-MAID models will be updated using all available new data.
  • Data on photoproduction off neutrons from MAMI and ELSA will be partially analyzed. Within this project the helicity dependence of π0 photoproduction will be precisely determined in the energy range of MAMI.
  • The decays J/ψ → n̅pπ-, J/ψ → p̅nπ+, and J/ψ → p̅pπ0 will be reconstructed using the full data set from the BESIII experiment. An interpretation of the angular distributions using a partial wave analysis based on an isobar model will be performed.
  • Preliminary results on decays into pp̅ → η and p̅p → η' final states will be available.
  • A benchmark calculation of the a0 mass in two-flavor LQCD will be performed. Results on the η and a0 masses in 2+1 flavor QCD with heavier-than-physical kaons as well as exploratory calculations of the a0 in the full two-channel problem are expected.