Fermi LAT Search for Photon Lines from 30 to 200 GeV and Dark Matter
  Implications
  Dark matter (DM) particle annihilation or decay can produce monochromatic
$\gamma$-rays readily distinguishable from astrophysical sources. $\gamma$-ray
line limits from 30 GeV to 200 GeV obtained from 11 months of Fermi Large Area
Space Telescope data from 20-300 GeV are presented using a selection based on
requirements for a $\gamma$-ray line analysis, and integrated over most of the
sky. We obtain $\gamma$-ray line flux upper limits in the range $0.6-4.5\times
10^{-9}\mathrm{cm}^{-2}\mathrm{s}^{-1}$, and give corresponding DM annihilation
cross-section and decay lifetime limits. Theoretical implications are briefly
discussed.
