A model for $F_L$ and $R=F_L/F_T$ at low $x$ and low $Q^2$

B. Badelek, J. Kwiecinski, A. Stasto

A model for the longitudinal structure function $F_L$ at low $x$ and low $Q^2$ is presented, which includes the kinematical constraint $F_L\sim Q^4$ as $Q^2\to 0$. It is…