2003/03/17 by Thomas D. Cohen, Daniel C. Dakin
Physics and Astronomy · #High-Energy Particle Collisions Research #Isospin #Mathematical physics #Mean field theory #Momentum (technical analysis) #Nuclear physics #Nucleon #Observable #Order (exchange) #Particle physics #Particle physics theoretical and experimental studies #Physics #Proton #Quantum Chromodynamics and Particle Interactions #Quantum chromodynamics #Quantum mechanics #Scattering #Spin (aerodynamics) #hep-ph
paper · pdf · doi:10.1103/physrevc.68.017001
published as Phys.Rev. C68 (2003) 017001 · 5 pages, 1 figure
arxiv created 2003/03/17 · openalex publication_date 2003/07/28 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The spin-flavor structure of certain nucleon-nucleon scattering observables derived from the large-Nc limit of QCD in the kinematical regime where time-dependent mean-field theory is valid is discussed. In a previous work [T.D. Cohen and B.A. Gelman, Phys. Lett. B 540, 227 (2002)], this regime was taken to be where the external momentum was of the order of Nc which precluded the study of differential cross sections in elastic scattering. Here it is shown that the regime extends down to the order of Nc1/2 which includes the higher end of the elastic regime. The prediction is that in the large-Nc limit, observables describable via mean-field theory are unchanged when both the spin and isospin of either nucleon are flipped. This prediction is tested for proton-proton and neutron-proton elastic scattering data and found to fail badly. We argue that this failure can be traced to a lack of a clear separation of scales between momentum of the order of Nc1/2 and Nc1 when Nc is as small as three. The situation is compounded by an anomalously low particle production threshold due to approximate chiral symmetry.