  Collective off resonant scattering of coherent light by a cold gas induces
long-range interactions via interference of light scattered by different
particles. In a 1D configuration these interactions grow particularly strong
for particles trapped along an optical nanofiber. We show that there exists a
threshold pump laser intensity, above which the gas can be found in a
crystalline, selfsustained order. In the nonabsorbing regime we determine the
critical condition for the onset of order as well as the forms of particle
density and scattered field patterns along the fiber above threshold.
Surprisingly, there can coexist multiple stationary solutions with distinct
density and field profiles.
