Clocking femtosecond collisional dynamics via resonant X-ray spectroscopy by van den Berg, Q, Fernandez-Tello, E, Burian, T, Chalupský, J, Chung, H, Ciricosta, O, Dakovski, G, Hájková, V, Hollebon, P, Juha, L, Krzywinski, J, Lee, R, Minitti, M, Preston, T, de la Varga, A, Vozda, V, Zastrau, U, Wark, J, Velarde, P, Vinko, S