Detection of Baryon Acoustic Oscillation Features in the Large-Scale
  3-Point Correlation Function of SDSS BOSS DR12 CMASS Galaxies
  We present the large-scale 3-point correlation function (3PCF) of the SDSS
DR12 CMASS sample of $777,202$ Luminous Red Galaxies, the largest-ever sample
used for a 3PCF or bispectrum measurement. We make the first high-significance
($4.5\sigma$) detection of Baryon Acoustic Oscillations (BAO) in the 3PCF.
Using these acoustic features in the 3PCF as a standard ruler, we measure the
distance to $z=0.57$ to $1.7\%$ precision (statistical plus systematic). We
find $D_{\rm V}= 2024\pm29\;{\rm Mpc\;(stat)}\pm20\;{\rm Mpc\;(sys)}$ for our
fiducial cosmology (consistent with Planck 2015) and bias model. This
measurement extends the use of the BAO technique from the 2-point correlation
function (2PCF) and power spectrum to the 3PCF and opens an avenue for deriving
additional cosmological distance information from future large-scale structure
redshift surveys such as DESI. Our measured distance scale from the 3PCF is
fairly independent from that derived from the pre-reconstruction 2PCF and is
equivalent to increasing the length of BOSS by roughly 10\%; reconstruction
appears to lower the independence of the distance measurements. Fitting a model
including tidal tensor bias yields a moderate significance ($2.6\sigma)$
detection of this bias with a value in agreement with the prediction from local
Lagrangian biasing.
