  The properties of the Xi(1530) resonance are investigated in the Lambdac+ -->
Xi- pi+ K+ decay process. The data sample was collected with the BaBar detector
at the SLAC PEP-II asymmetric-energy e+ e- collider operating at center of mass
energies 10.58 and 10.54 GeV. The corresponding integrated luminosity is
approximately 230 inverse fb. The spin of the Xi(1530) is established to be
3/2. The existence of an S-wave amplitude in the Xi- pi+ system is inferred,
and its interference with the Xi(1530)0 amplitude provides the first clear
demonstration of the Breit-Wigner phase motion expected for the Xi(1530). The
P_1(cos[theta(Xi-)]) Legendre polynomial moment indicates the presence of a
significant S-wave amplitude for Xi- pi+ mass values above 1.6 GeV/c^2, and a
dip in the mass distribution at approximately 1.7 GeV/c^2 is interpreted as due
to coherent addition of a Xi(1690)0 contribution to this amplitude. This would
imply J^P=1/2^- for the Xi(1690). Attempts at fitting the Xi(1530)0 lineshape
yield unsatisfactory results, and this failure is attributed to interference
effects associated with the amplitudes describing the K+ pi+ and/or Xi- K+
systems.
