Search

We investigate the Jp = 1/2- baryons in the octets based on flavor SU(3) symmetry. Since baryons with same quantum numbers can mix with each other, we consider the mixing between two octets before their mixing with the singlet. Most predicted decay widths are consistent with the experimental data, and meanwhile we predict two possible Ξ mass ranges of the two octets. [ABSTRACT FROM AUTHOR]

The pentaquark state of Θ+(uudd&smacr;) has been observed to decay with two decay modes: Θ+ → nK+ and Θ+ → pK0. The decay probability ratio of the two decay modes is studied with general symmetry consideration of isospin, spin and parity. We arrive at a result of the ratio [This symbol cannot be presented in ASCII format]2L+1, which is valid for the Θ+ state to be a pure isoscalar or isovector state, or an isoscalar and isovector mixing state, or an isotensor state with mixture of isoscalar and isovector components with coefficients α and β. The dependence on spin and parity of the pentaquark Θ+ state is found to be small due to small difference between the center-of-mass decay momenta k1 and k2 of the two decay modes. We also provide an analysis on the constraint of the isospin of Θ+ from the absence of a peak in the pK+ invariant mass distribution in the γp → pK+K- process. Future experimental results about the decay probability ratio may provide information about the properties of the pentaquark Θ+ state. [ABSTRACT FROM AUTHOR]

It is shown that the exotic non-qqq hadrons of pentaquark qqqq&qmacr; states can be clearly distinguished from the conventional qqq-baryon resonances or their hybrids if the flavor of &qmacr; is different from any of the other four quarks. We suggest the physical process p(e, e'K[sup -]Z(uuud&smacr;), which can be investigated at the Thomas Jefferson National Accelerator Facility (JLab), as an ideal process to search for the existence or nonexistence of the exotic hadron of minimal pentaquark state Z(uuud&smacr;). [ABSTRACT FROM AUTHOR]