 Displacement and current bandwidths of a series RLC circuit

Write ${\omega }_0^2=1/(LC)$ and $\gamma =R/L$ for a series RLC circuit. The squared charge response has denominator $D=({\omega }_0^2-{\omega }^2{)}^2+{\gamma }^2{\omega }^2$. Its nonzero resonance peak occurs at ${\omega }_r^2={\omega }_0^2-{\gamma }^2/2$. The two squared half-height frequencies, when both exist, areTheir difference in angular frequencies is only approximately $\gamma$ at large quality factor. The electric current instead has $|I{|}^2=|V{|}^2/[R^2+(\omega L-1/(\omega C){)}^2]$. Its exact half-power frequencies satisfy $|\omega L-1/(\omega C)|=R$, whose positive roots differ by $R/L$, independently of capacitance. Thus an exact capacitance-independent bandwidth applies to current or resistor-voltage output; capacitor-voltage output is a low-pass response with a possible resonant peak.