  Using a spin-only model, we compute spin excitation spectra in a
bond-centered stripe state with long-range magnetic order. We employ a bond
operator formalism, which naturally captures both dimerization and broken spin
symmetry in a unified framework. At low energies, the spin excitations resemble
spin waves, but at higher energies they are very similar to spin-1 excitations
of isolated spin ladders. Our theory does well describe neutron scattering data
[J. M. Tranquada et al., Nature 429, 534 (2004)] on LaBaCuO, pointing towards
bond order in this material.
