Upper Bound of 0.28 eV on Neutrino Masses from the Largest Photometric Redshift Survey

We present a new limit of Sigma m(nu) <= 0.28 (95% CL) on the sum of the neutrino masses assuming a flat Lambda CDM cosmology. This relaxes slightly to Sigma m(nu) <= 0.34 and Sigma m(nu) <= 0.47 when quasinonlinear scales are removed and w not equal -1, respectively. These are derived from a new photometric catalogue of over 700 000 luminous red galaxies (MegaZ DR7) with a volume of 3.3 (Gpc h(-1))(3) and redshift range 0.45 < z < 0.65. The data are combined with WMAP 5-year CMB, baryon acoustic oscillations, supernovae, and a Hubble Space Telescope prior on h. When combined with WMAP these data are as constraining as adding all supernovae and baryon oscillation data available. The upper limit is one of the tightest constraints on the neutrino from cosmology or particle physics. Further, if these bounds hold, they all predict that current-to-next generation neutrino experiments, such as KATRIN, are unlikely to obtain a detection.