Investigation of High Energy Behaviour of HERA Data

We analyse the high precision HERA $F_2$ data in the low-$x$ regions, $x<0,01$ and the very-low-$x$, $x<0.001$, regions using $\lambda$-Fits. $\lambda$ is a measure of the rate of rise of $F_2$ defined by $F_2 \propto (1/x)^{\lambda}$. We show that $\lambda$ determined in these two regions, at various $Q^2$ values, is systematically smaller in the very-low-$x$ region as compared to the low-$x$ region. We discuss some possible physical interpretations of this effect.