Adroit Limbs

Overview of Non-Relativistic QCD

“…This is the vNRQCD approach first proposed in [18] (see also [19]). The scale Λ QCD has not been discussed so far in this approach, and, in fact, a consistent formulation has only become available recently [20] (see also [21,22]).…”

Aspects of nucleon chiral perturbation theory

“…In this section I will be concerned with the inclusion the low-lying spin-1/2 baryons (the nucleons) to the effective field theory. I will consider the two flavor case and mostly work in the isospin limit m u = m d = m. For a more detailed account, I refer to A. Manohar's lecture [2]. The inclusion of such matter fields is less straightforward since these particles are not related to the symmetry violation.…”

“…combinations of zero or one quark mass insertions with zero to three derivatives. These terms are collected in L (2,3) πN and a complete list of them can be found in Krause's paper [4] (for the case of SU(3)). Second, the finiteness of the nucleon mass in the chiral limit and the fact that its value is comparable to the chiral symmetry breaking scale Λ ∼ M ρ complicates the low energy structure.…”

“…A systematic analysis to this order in the chiral expansion is not yet available. In Manohar's lecture [2,15], an alternative approach of including the low-lying spin-3/2 decuplet in the effective field theory is discussed (based on phenomenological considerations supplemented with some arguments from the large N c world). In that fashion, one sums up a certain subset of graphs starting at order q 4 .…”