  High energy proton-proton and antiproton-proton elastic scattering are
studied first in a model where the nucleon has an outer cloud and an inner
core. Elastic scattering is viewed as due to two processes: a) diffraction
scattering originating from cloud-cloud interaction; b) a hard or large |t|
scattering originating from one nucleon core scattering off the other via
vector meson omega exchange, while their outer clouds interact independently.
The omega-exchange amplitude shows that omega behaves like an elementary vector
meson at high energy, contrary to a regge pole behavior. This behavior,
however, can be understood in the nonlinear sigma-model where omega couples to
a topological baryonic current like a gauge boson, and the nucleon is described
as a topological soliton. Further investigation shows that the underlying
effective field theory model is a gauged linear sigma-model that has not only
the pion sector and the Wess-Zumino-Witten action of the nonlinear sigma-model,
but also a quark-scalar sector. The nucleon structure that emerges is that the
nucleon has an outer cloud of quark-antiquark condensed ground state, an inner
core of topological baryonic charge probed by omega, and a still smaller
quark-bag containing massless valence quarks. Large |t| pp elastic scattering
is attributed to valence quark-quark elastic scattering, which is taken to be
due to the hard pomeron. The model is applied to predict pp elastic
differential cross section at LHC at c.m. energy 14 TeV and |t| = 0 - 10 GeV*2.
If our predicted differential cross section is quantitatively confirmed by
precise measurement at LHC by the TOTEM group, then it will indicate that
various novel ideas developed over the last four decades to describe the
nucleon combine and lead to a unique physical description of its structure.
