Nucleon structure functions from the NJL-model chiral soliton

Abstract

We present numerical simulations for unpolarized and polarized structure functions in a chiral soliton model. The soliton is constructed self-consistently from quark fields from which the structure functions are extracted. Central to the project is the implementation of regularizing the Dirac sea (or vacuum) contribution to structure functions from first principles. We discuss in detail how sum rules are realized at the level of the quark wave-functions in momentum space. The comparison with experimental data is convincing for the polarized structure functions but exhibits some discrepancies in the unpolarized case. The vacuum contribution to the polarized structure functions is particularly small.

Chiral Soliton Models and Nucleon Structure Functions

“…The results discussed in this section are mostly taken from Ref. [18]. There are several steps until we can perform a sensible comparison with experimental data.…”

“…We will refrain from presenting lengthy formulas as, e.g. the extremely bulky expressions involving the Fourier transforms of the radial functions in Ψ α [18]. Rather we focus on explaining the treatment of the pole terms without going into too much details.…”

“…For this example we will also explain how sum rules are established in the fully regularized formulation. For further details on other structure functions, that are obtained using quite a similar procedure, we refer to to original literature [17,18].…”

“…At this stage of the project we will not identify the quark degrees of freedom with those of QCD, which, for example, means that the current quark mass is a free parameter. The theoretical framework has been derived already some time ago [17] while the numerical results arising from costly simulations have only been obtained recently [18]. As mentioned above, a major motivation for the soliton picture arises from generalizing QCD to a non-abelian gauge theory with large N C .…”

Scattering of Kinks in Noncanonical sine-Gordon Model

“…They are applied in many branches of physics because of their stable nature against dispersive effects. For examples; they are applied in cosmology for studying the fractal structure of the cosmic domain walls [2,3], in condensed matter physics they are used to study Bose-Einstein condensates [4] and for studying domain walls in ferromagnets [6] and ferroelectrics [7], in particle physics, they are used as a model of hadrons [8][9][10].…”