Single-Inclusive Jet Production in Polarized pp Collisions at O(alpha_s^3)
B. Jager, M. Stratmann, W. Vogelsang
TL;DR
The paper develops an analytic next-to-leading order QCD framework for single-inclusive jet production in longitudinally polarized pp collisions using the small-cone approximation. By leveraging previously computed single-parton-inclusive cross sections, it converts them into jet cross sections and cross-checks the polarized results against unpolarized literature and Monte-Carlo comparisons. The approach yields fast, accurate predictions for $A_{LL}^{jet}$ and allows assessment of the SCA’s validity for RHIC kinematics, supporting forthcoming STAR data analyses and $\Delta g$ studies. The work reduces scale uncertainties at NLO and provides a practical tool for global analyses of polarized parton densities.
Abstract
We present a next-to-leading order QCD calculation for single-inclusive high-p_T jet production in longitudinally polarized pp collisions within the ``small-cone'' approximation. The fully analytical expressions obtained for the underlying partonic hard-scattering cross sections greatly facilitate the analysis of upcoming BNL-RHIC data on the double-spin asymmetry A_{LL}^{jet} for this process in terms of the unknown polarization of gluons in the nucleon. We simultaneously rederive the corresponding QCD corrections to unpolarized scattering and confirm the results existing in the literature. We also numerically compare to results obtained with Monte-Carlo methods and assess the range of validity of the ``small-cone'' approximation for the kinematics relevant at BNL-RHIC.