A Diquark-Triquark Model for the KN Pentaquark

We propose a model for the recently discovered Theta^+ exotic KN resonance as a novel kind of a pentaquark with an unusual color structure: a color triplet (ud) diquark, coupled to a color anti-triplet (ud s-bar) triquark in a relative P-wave. The state has J^P=1/2^+, I=0 and is an antidecuplet of SU(3)_f. A rough mass estimate of this pentaquark is close to experiment.Comment: A condensed and amended version of hep-ph/0307243, as published in PLB, to include pentaquark analysis only, with a revised title and some additional discussion of the Xi states in the 10-ba

On Reconciling Gottfried Sum Rule Violation with Cabibbo Theory

We discuss the seemingly contradictory constraints of simultaneously preserving the SU(3)-symmetric Cabibbo description of the weak vector baryon matrix elements, accounting for SU(3) flavor symmetry breaking and describing the observed violation of the Gottfried Sum Rule. We try to construct a simple model that will satisfy these constraints and use it to explain the generic difficulties and tradeoffs.Comment: 10 pages, late