| ABSTRACT: |
Three constituent quarks in light baryons create a strong pion field
as a consequence of chiral symmetry; a pion field implies that there are
additional quark-antiquark pairs in baryons. It solves an old paradox:
why three quarks carry only a small fraction of the nucleon spin and
why the nucleon sigma term is large.
We present a relativistic-invariant technique how to describe
the 3-, 5-, 7-... quark components in baryons. We reproduce the
well-known 3-quark wave function in ordinary baryons but with specific
relativistic corrections which are generally not small. In particular,
the normalization of the 5-quark component in the nucleon is about 40%
of the 3-quark component. We give explicitly the 5-quark wave functions
of the nucleon and of the exotic pentaquark Theta-plus. We estimate the
Theta+ width which turns out to be very small, about 2 MeV.
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