Energy evolution and the Bose-Einstein enhancement for double parton densities

TL;DR

This paper investigates how Bose-Einstein enhancement influences double parton densities during BFKL evolution, revealing significant correlations at high energies and quantifying the corrections due to color factors.

Contribution

It demonstrates that Bose-Einstein enhancement causes strong correlations in double parton densities, with a detailed analysis of energy dependence and color correction effects.

Findings

Double parton densities are significantly larger than the product of single densities due to Bose-Einstein effects.

The ratio of double to squared single densities scales with energy as (1/x)^{δ_2} with δ_2 much less than 1.

Color corrections to double parton densities originate solely from Bose-Einstein enhancement.

Abstract

In this paper we found that the Bose-Einstein enhancement generates the strong correlations, which increase with energy in the BFKL evolution. This increase leads to the double parton densities ( $\Phi$), that are much larger than the product of the single parton densities ($\phi$). However, numerically, it turns out that the ratio $\Phi/\phi^2 \propto \Lb 1/x\Rb^{\delta_2}$ with $\delta_2 \sim \bas/\Lb N^2_c - 1\Rb^{2/3}\,\,\ll\,\,1$ and we do not expect a large correction for the accessible range of energies. However, for $N_c=3$ it tuns out that $\delta_2 = 0.07 \Delta_{\rm BFKL}$ where $\Delta_{\rm BFKL}$ is the intercept of the BFKL Pomeron and we can anticipate an substantial increase for the range of rapidities $Y \sim 20$.It is shown that all $1/(N^2_c -1)$ corrections to the double parton densities stem from the Bose-Einstein enhancement.