Longitudinal Structure Function FL at Small x Extracted from the Berger–Block–Tan Parametrization of F2

The longitudinal structure function FL(x,Q2) is extracted at low values of the Bjorken variable x from the Berger–Block–Tan parametrization of F2(x,Q2). The obtained FL(x,Q2) does not violate the high-energy asymptotic Froissart boundary and is in a reasonable good agreement with the available experimental data.