Angular correlation function of 1.5 million LRGs: clustering evolution
  and a search for BAO
  We present the angular correlation function measured from photometric samples
comprising 1,562,800 luminous red galaxies (LRGs). Three LRG samples were
extracted from the Sloan Digital Sky Survey (SDSS) imaging data, based on
colour-cut selections at redshifts, z ~ 0.35, 0.55 and 0.7 as calibrated by the
spectroscopic surveys, SDSS-LRG, 2dF-SDSS LRG and QSO (2SLAQ), and the AAOmega
LRG survey. The galaxy samples cover ~7600 s.q.deg of the sky, probing a total
cosmic volume of ~5.5 h^-3} Gpc^3.
  The small and intermediate scale correlation functions generally show
significant deviations from a single power-law fit with a well-detected break
at ~1 h^-1 Mpc, consistent with the transition scale between the 1- and 2-halo
terms in halo occupation models. For galaxy separations 1-20 h^-1 Mpc and at
fixed luminosity, we see virtually no evolution of the clustering with redshift
and the data is consistent with a simple high peaks biasing model where the
comoving LRG space density is constant with z. At fixed z, the LRG clustering
amplitude increases with luminosity in accordance with the simple high peaks
model, with a typical LRG dark matter halo mass 10^13-10^14 h^-1 M_sol. For r <
1 h^-1 Mpc, the evolution is slightly faster and the clustering decreases
towards high redshift consistent with a virialised clustering model. However,
assuming the HOD and LCDM halo merger frameworks, ~2-3 per cent per Gyr of the
LRGs is required to merge in order to explain the small scales clustering
evolution, consistent with previous results [abridge].
