2024/01/10 by Brandon J. Manley, Manley, Brandon
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Phenomenology (hep-ph) #High-Energy Particle Collisions Research #Nuclear Experiment (nucl-ex) #Nuclear Theory (nucl-th) #Pulsars and Gravitational Waves Research #Quantum Chromodynamics and Particle Interactions
paper · pdf · doi:10.48550/arxiv.2401.05508
openalex publication_date 2024/01/10 · openalex created_date 2024/01/13 · openalex updated_date 2026/08/01
We construct an exact solution to the revised small-x orbital angular momentum (OAM) evolution equations derived recently, based on an earlier work. These equations are derived in the double logarithmic approximation (summing powers of αs ln2(1/x) with αs the strong coupling constant and x the Bjorken x variable) and the large-Nc limit, with Nc the number of quark colors. From our solution, we extract the small-x, large-Nc expressions of the quark and gluon OAM distributions. Additionally, we determine the large-Nc small-x asymptotics of the OAM distributions to be L_q+q(x,Q2) ∼ LG(x,Q2) ∼ ΔΣ(x,Q2) ∼ ΔG(x,Q2) ∼ ((1)/(x) )αh, with the intercept αh the same as obtained in the small-x helicity evolution, which can be approximated as αh ≈ 3.66074 √((αs Nc)/(2π)). This result is in complete agreement with the literature. Additionally, we calculate the ratio of the quark and gluon OAM distributions to the flavor-singlet quark and gluon helicity parton distribution functions respectively in the small-x region.