Beam-helicity asymmetries in double-charged-pion photoproduction on the proton.

Beam-helicity asymmetries for the two-pion-photoproduction reaction gammap-->ppi(+)pi(-) have been studied for the first time in the resonance region for center-of-mass energies between 1.35 and 2.30 GeV.

First measurement of transferred polarization in the exclusive ep-->e'K+Lambda--> reaction.

The first measurements of the transferred polarization for the exclusive e-->p-->e(')K+Lambda--> reaction have been performed at Jefferson Laboratory using the CLAS spectrometer. A 2.567 GeV beam was used to measure the hyperon polarization over Q2 from 0.

Spin, parity, and nature of the xi(1620) resonance.

Using a unitary extension of chiral perturbation theory with a lowest-order s-wave SU(3) chiral Lagrangian we study low-energy meson-baryon scattering in the strangeness S=-2 sector. A scattering-matrix pole is found around 1605 MeV which corresponds to an s-wave Xi resonance with J(P)=1/2(-). We identify this resonance with the Xi(1620) state, quoted by the Particle Data Group with I=1/2 but with unknown spin and parity.