Dysonian Electron-Spin-Resonance Spectra of Local Magnetic Moments in Metals

The absorptive and dispersive components of the frequency-dependent magnetic susceptibility both contribute to the electron-spin resonance (ESR) radio-frequency (rf) power absorption of local magnetic moments in metals according to Dyson's theory. The magnetic-field prefactor present in the expression for this power absorption has been omitted in the past when fitting Dyson's lineshape to the observed field derivative of broad ESR rf power absorption spectra but is shown here to significantly influence such fits and therefore also the quantitative physical interpretations of the temperature-dependent fit parameters.
Comment: The paper is based on predictions of the Bloch equations. This is not correct for wide absorption lines for which the modified Bloch equations must be used instead. The correct theory is given in arXiv:1809.02653v4