Fig. 1: Experimental principle and onset of complexity in reaction outcomes.
From: Colliding heavy nuclei take multiple identities on the path to fusion
a Depicted is the internuclear potential (blue) of 40Ca+208Pb nuclei (with centre-to-centre separation R), the nuclear potential Vnuc (red)52, and the sum of the Coulomb and centrifugal potentials Vcoul + Vcent (green). The yellow crosses show the deduced distance between the barrier RB and the distance of closest approach \({R}_{\min }\), \({R}_{\min }-{R}_{{{{{{{{\rm{B}}}}}}}}}\), at each measured energy Ecm, taking into account the change in angular momentum l at the measurement angle. b Left axis: proportion of the reflected flux P/Preflected that is made up of 40Ca (lilac squares), statistical errors are smaller than the points. Right axis: The smallest number of nuclide pairs required to make up 95% of the reflected flux (N95, green diamonds). c The deduced excitation energy distribution Ex. To show the evolution of the excitation energy with decreasing surface separation, the probabilities were normalised to the total reflected flux such that the integral at each \({R}_{\min }-{R}_{{{{{{{{\rm{B}}}}}}}}}\) is equal to 1. These distributions will be modulated by absorption at higher energies (above E/VB = 0.91, below \({R}_{\min }-{R}_{{{{{{{{\rm{B}}}}}}}}}=1.93\) fm (Supplementary Fig. 2a)) which will not be equally likely for all Ex. The data has been interpolated between measurement energies using Delaunay triangulation57. The black points show the mean excitation energy at each measured energy.
