Are Type Ia Supernovae in Restframe $H$ Brighter in More Massive
  Galaxies?
  We analyze 143 Type Ia supernovae (SNeIa) observed in $H$ band (1.6-1.8
$\mu$m) and find SNeIa are intrinsically brighter in $H$-band with increasing
host galaxy stellar mass. We find SNeIa in galaxies more massive than
$10^{10.43} M_{\odot}$ are $0.13 \pm 0.04$ mag brighter in $H$ than SNeIa in
less massive galaxies. The same set of SNeIa observed at optical wavelengths,
after width-color-luminosity corrections, exhibit a $0.10 \pm 0.03$ mag offset
in the Hubble residuals. We observe an outlier population ($|\Delta H_{\rm
max}| > 0.5$ mag) in the $H$ band and show that removing the outlier population
moves the mass threshold to $10^{10.65} M_{\odot}$ and reduces the step in $H$
band to $0.08 \pm 0.04$ mag, but the equivalent optical mass step is increased
to $0.13 \pm 0.04$ mag. We conclude the outliers do not drive the
brightness--host-mass correlation. Less massive galaxies preferentially host
more higher-stretch SNeIa, which are intrinsically brighter and bluer. It is
only after correction for width-luminosity and color-luminosity relationships
that SNeIa have brighter optical Hubble residuals in more massive galaxies.
Thus finding SNeIa are intrinsically brighter in $H$ in more massive galaxies
is an opposite correlation to the intrinsic (pre-width-luminosity correction)
optical brightness. If dust and the treatment of intrinsic color variation were
the main driver of the host galaxy mass correlation, we would not expect a
correlation of brighter $H$-band SNeIa in more massive galaxies.
