paper

Perturbative QCD and beyond: azimuthal angle correlations in deuteron-deuteron scattering from Bose-Einstein correlations

arXiv:1611.01653 · doi:10.1103/PhysRevD.95.014034

Abstract

In this paper, we found within the framework of perturbative QCD, that in deuteron-deuteron scattering the Bose-Einstein correlations due to two parton showers production, induce azimuthal angle correlations, with three correlation lengths: the size of the deuteron ( $R_{D}$ ), the proton radius ( $R_{N}$ ), and the size of the BFKL Pomeron which, is closely related to the saturation momentum ( $R_{c} \sim 1/ Q_{s}$ ). These correlations are independent of the values of rapidities of the produced gluons (long range rapidity correlations), for large rapidities ($\bas |y_1 - y_2| \geq 1$), and have no symmetry with respect to $I ¨ \to I ¨ - I ¨ $ ( $p_{T 1} \to - p_{T 1}$ ). Therefore, they give rise to $v_{n}$ for all values of $n$ , not only even values. The contributions with the correlation length $R_{D}$ and $R_{N}$ crucially depend on the non-perturbative contributions, and to obtain estimates of their values, requiries a lot of modeling, while the correlations with $R_{c} \sim 1/ Q_{s}$ have a perturbative QCD origin, and can be estimated in the ColorGlass Condensate (CGC) approach.

23pp, 18 figures in eps files