# Investigation of High Energy Behaviour of HERA Data

## TL;DR

This paper analyzes HERA data to study how the structure function $F_2$ rises at low and very-low-$x$ regions, revealing a systematic difference in the rise rate that may have physical implications.

## Contribution

It presents a detailed analysis of the $F_2$ structure function at very low-$x$ using $\lambda$-Fits, highlighting a systematic difference in the rise rate between low and very-low-$x$ regions.

## Key findings

- $\lambda$ is smaller in very-low-$x$ compared to low-$x$ regions.
- The difference in $\lambda$ varies with $Q^2$.
- Physical interpretations of the observed effect are discussed.

## Abstract

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.