Cosmic distances probed using the BAO ring
  The cosmic distance can be precisely determined using a `standard ruler'
imprinted by primordial baryon acoustic oscillation (hereafter BAO) in the
early Universe. The BAO at the targeted epoch is observed by analysing galaxy
clustering in redshift space (hereafter RSD) for which a theoretical
formulation is not yet fully understood, and thus makes this methodology
unsatisfactory. The BAO analysis following a full RSD modelling is contaminated
by systematic uncertainties due to a non-linear smearing effects such as
non-linear corrections and by random viral velocity of galaxies. However, the
BAO can be probed independently of RSD contamination using the BAO peak
positions located in the 2D anisotropic correlation function. A new methodology
is presented to measure peak positions, to test whether it is also contaminated
by the same systematics in RSD, and to provide the radial and transverse cosmic
distances determined by the 2D BAO peak positions. We find that in our model
independent anisotropic clustering analysis we can obtain about $2\%$ and $5\%$
constraints on $D_A$ and $H^{-1}$ respectively with current BOSS data, which is
competitive with other analysis.
