Speaker
Amir Rezaeian
(Universidad Tecnica Federico Santa Maria)
Description
We confront the Impact-Parameter dependent Color Glass Condensate dipole (b-CGC) model to the recently released high precision combined HERA data and obtain its parameters. The b-CGC results are then compared to data at small-x for the structure function, the longitudinal structure function, the charm structure function, exclusive vector meson (J/\psi, \phi, \rho) production and Deeply Virtual Compton Scattering (DVCS). We also compare our results with the Impact-Parameter dependent Saturation model (IP-Sat) which has also been recently updated with the combined HERA data. The b-CGC and the IP-Sat models have also been applied to proton-proton and proton-nucleus collisions and provide the basis for modeling initial conditions in heavy ion collisions.
We show that most features of inclusive DIS and exclusive diffractive data, including the Q^2, W, |t| and x dependence are correctly reproduced in both models. Nevertheless, the b-CGC and the IP-Sat models give different predictions beyond the current HERA kinematics, namely for the structure functions at very low x and high virtualities Q^2, and for the exclusive diffractive vector meson and DVCS production at high t. We show that both models give approximately similar saturation scale Q_S<1 GeV for the proton in HERA kinematics, and also both models lead to the same conclusion that the typical impact-parameter probed in the total \gamma^{*}p cross-section is about b\approx 2\div 3 GeV^{-1}. We provide some predictions for future electron-proton colliders.
This talk is mainly based on: A. H. Rezaeian and I. Schmidt, Phys. Rev. D88, 074016 (2013) [arXiv:1307.0825].
Author
Amir Rezaeian
(Universidad Tecnica Federico Santa Maria)
