Carbon K-shell photoionization of fixed-in-space Ethylene Molecules

Using the COLTRIMS technique we performed a kinematically complete experiment measuring photoionization of the carbon K-edge of the fixed in space ethylene molecules for photon energies (293, 302, 306, 318eV), while focusing on the symmetric break-up channel (CH2+ + CH2+). The coincidenct measurements the of reaction products along with data collection and analysis on the event-by-event basis allowed us to obtain the multi differential angular distribution of photoelectrons in the body-fixed frame of ethylene molecule. We also completed very comprehensive theoretical study of the reaction. A set of dipole transition matrix elements was calculated and extracted (7 amplitudes and 5 relative phases) from the experimental results. These matrix elements along with the complete angular distributions showed a very good qualitative agreement between the experiment and the theoretical model used. From the l = 3, m = 0 partial wave contribution to the electron angular distribution we concluded the presence of an f -wave shape resonance found around 10eV above the carbon K-edge in the ethylene molecule.