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

摘要

In this paper, we find, within the framework of perturbative QCD, that in deuteron-deuteron scattering Bose-Einstein correlations, due to production of two-parton showers, 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 Balitski-Fadin-Kuraev-Lipatov (BFKL) Pomeron, which is closely related to the saturation momentum (R_c ~ 1/Q_s). These correlations are independent of the values of rapidities of the produced gluons (long range rapidity correlations) for large rapidities ( α_S|y_1 - y_2| ≥ 1) and have no symmetry with respect to ф → π - ф (p_(T1) → -p_(T1)). Therefore, they give rise to v_n for all values of n, not only for even values. The contributions of the correlation lengths R_D and R_N crucially depend on the nonperturbative contributions, and obtaining estimates of their values requires a lot of modeling, while the correlations with R_c ~ 1/Q_s have a perturbative QCD origin and can be estimated in the color glass condensate approach.