Study of coupled states for the (4s(2))S-1+(4s4p)P-3 asymptote of Ca-2

The coupled states A(1)Sigma(u)(+) (D-1 + S-1), c(3)Pi(u) (P-3 + S-1) and a(3) Sigma(+)(u) (P-3 + S-1) of the calcium dimer are investigated in a laser induced fluorescence experiment combined with high-resolution Fourier-transform spectroscopy. A coupled state analysis of the observed levels, considering a potential model, which is complete within the subspace of relevant neighboring states, is performed using the Fourier Grid Hamiltonian method. We determine the potential energy curve of the A(1)Sigma(u)(+) and c(3)Pi(u) states and the strengths of the couplings between them. The c(3)Pi(u) and a(3) Sigma(u)(+) states are of particular importance for the description of collisional processes between calcium atoms in the ground state S-1(0) and excited state P-3(1) applied in studies for establishing an optical frequency standard with Ca.