The distance between upper & lower half power frequencies, measured in hertz or in rad/sec, is called as the banwidth BW.
BW = ω2 - ω1 in rad/sec.
or BW = f2 - f1 in Hz
The resonant frequency ω0 is geometric mean of ω1 and ω2.
ω0 = √(ω1 ω2) and f0 = √ (f1 f2)