Towards the test of saturation physics beyond leading logarithm.
We present results from the first next-to-leading-order (NLO) numerical analysis of forward hadron production in pA and dA collisions in the small-x saturation formalism. Using parton distributions and fragmentation functions at NLO, as well as the dipole amplitude from the solution to the Balitsky-Kovchegov equation with running coupling, together with the NLO corrections to the hard coefficients, we obtain a good description of the available RHIC data in dAu collisions. In the large p⊥ region beyond the saturation scale, we find that the NLO correction becomes dominant and negative, which indicates that other physics beyond NLO becomes important and should also be taken into account. Furthermore, we make predictions for forward hadron production in pPb collisions at the LHC. This analysis not only incorporates the important NLO corrections for all partonic channels, but also reduces the renormalization scale dependence and helps to significantly reduce the theoretical uncertainties. It therefore provides a precise test of saturation physics beyond the leading logarithmic approximation.
Department of Physics, Pennsylvania State University, University Park, Pennsylvania 16802, USA and RIKEN center, Brookhaven National Laboratory, Upton, New York 11973, USA and Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, Kraków, Poland.
Anna M
AM
Staśto
Key Laboratory of Quark and Lepton Physics (MOE) and Institute of Particle Physics, Central China Normal University, Wuhan 430079, China.
Bo-Wen
BW
Xiao
Department of Physics, Pennsylvania State University, University Park, Pennsylvania 16802, USA.
David
D
Zaslavsky