Speaker
Description
X-ray characteristic spectra constitute one of the most sensitive probes for testing relativistic quantum mechanics and quantum electrodynamics, playing a key role in both atomic physics research and industrial applications. Advanced relativistic theory has, however, been unable to predict such spectra, calling several foundational ideas into question. A core problem lies in the process to convergence and the lack of sensitive metrics for convergence of many-body systems. We present a new convergence metric for many-body systems: the radiative lifetime invariance metric ($\Sigma$ metric) which can be used to identify cases of false convergence that go undetected using previous criteria. This new metric suggests that the radiative lifetime of all upper states of the K$\alpha$ transition are the same within 0.347% under appropriate circumstances. we present a suite of newly developed convergence criteria which innovate upon best practice in many-body theory. By applying this suite we have develop a theoretical model for the copper K$\alpha$ satellite spectrum, which is the best-tested system experimentally and theoretically in X-ray physics, but has not yet been explained theoretically. We predict the dominant $[1s]\rightarrow[2p]$ transition spectrum, and all major satellite transition spectra. The resulting wavefunctions are highly convergent, according to the range of convergence metrics. The theoretical Cu K$\alpha$ spectrum is, for the first time, in strong agreement with the world leading experiments. We confirm the necessity and accuracy of: the diagram spectrum and the $[4s]$ satellite spectrum; define and demonstrate the necessity of a convergent $[3d]$ satellite spectrum; and for the first time, calculate and highlight the importance of the $[3p]$; $[3s]$; $[3d4s]$; and $[3d^2]$ shake-off satellite processes.