title: Multiparticle states in the S = 1 chain system CsNiCl3.
abstract: A continuum of magnetic states has been observed by neutron scattering from the spin-1 chain compound CsNiCl3 in its disordered gapped one-dimensional phase. Results using both triple-axis and time-of-flight spectrometers show that around the antiferromagnetic point Qc = pi, the continuum lies higher in energy than the Haldane gapped excitations. At 6 K the integrated intensity of the continuum is about 12(2)% of the total spectral weight. This result is considerably larger than the 1%-3% weight predicted by the nonlinear sigma model for the three-particle continuum.
authors.affiliation: Oxford Physics, Clarendon Laboratory, Oxford OX1 3PU, United Kingdom.
authors.forename: M
authors.initials: M
authors.lastname: Kenzelmann
authors.forename: R A
authors.initials: RA
authors.lastname: Cowley
authors.forename: W J
authors.initials: WJ
authors.lastname: Buyers
authors.forename: R
authors.initials: R
authors.lastname: Coldea
authors.forename: J S
authors.initials: JS
authors.lastname: Gardner
authors.forename: M
authors.initials: M
authors.lastname: Enderle
authors.forename: D F
authors.initials: DF
authors.lastname: McMorrow
authors.forename: S M
authors.initials: SM
authors.lastname: Bennington