Galaxy bias from galaxy-galaxy lensing in the DES Science Verification
  Data
  We present a measurement of galaxy-galaxy lensing around a magnitude-limited
($i_{AB} < 22.5$) sample of galaxies from the Dark Energy Survey Science
Verification (DES-SV) data. We split these lenses into three
photometric-redshift bins from 0.2 to 0.8, and determine the product of the
galaxy bias $b$ and cross-correlation coefficient between the galaxy and dark
matter overdensity fields $r$ in each bin, using scales above 4 Mpc/$h$
comoving, where we find the linear bias model to be valid given our current
uncertainties. We compare our galaxy bias results from galaxy-galaxy lensing
with those obtained from galaxy clustering (Crocce et al. 2016) and CMB lensing
(Giannantonio et al. 2016) for the same sample of galaxies, and find our
measurements to be in good agreement with those in Crocce et al. (2016), while,
in the lowest redshift bin ($z\sim0.3$), they show some tension with the
findings in Giannantonio et al. (2016). We measure $b\cdot r$ to be $0.87\pm
0.11$, $1.12 \pm 0.16$ and $1.24\pm 0.23$, respectively for the three redshift
bins of width $\Delta z = 0.2$ in the range $0.2<z <0.8$, defined with the
photometric-redshift algorithm BPZ. Using a different code to split the lens
sample, TPZ, leads to changes in the measured biases at the 10-20\% level, but
it does not alter the main conclusion of this work: when comparing with Crocce
et al. (2016) we do not find strong evidence for a cross-correlation parameter
significantly below one in this galaxy sample, except possibly at the lowest
redshift bin ($z\sim 0.3$), where we find $r = 0.71 \pm 0.11$ when using TPZ,
and $0.83 \pm 0.12$ with BPZ.
