  The measurement of gamma-ray lines from the decay chain of 56Ni provides
unique information about the explosion in supernovae. The 56Ni freshly-produced
in the supernova powers the optical light curve, as it emits gamma-rays upon
its radioactive decay to 56Co and then 56Fe. Gamma-ray lines from 56Co decay
are expected to become directly visible through the overlying white dwarf
material several weeks after the explosion, as they progressively penetrate the
overlying material of the supernova envelope, diluted as it expands. The lines
are expected to be Doppler-shifted or broadened from the kinematics of the 56Ni
ejecta. With the SPI spectrometer on INTEGRAL and using an improved
instrumental background method, we detect the two main lines from 56Co decay at
847 and 1238 keV from SN2014J at 3.3 Mpc, significantly Doppler-broadened, and
at intensities (3.65+/-1.21) 10^-4 and (2.27+/-0.69) 10^-4 ph cm^-2s^-1,
respectively, at brightness maximum. We measure their rise towards a maximum
after about 60-100 days and decline thereafter. The intensity ratio of the two
lines is found consistent with expectations from 56Co decay (0.62+/-0.28 at
brightness maximum, expected is 0.68). We find that the broad lines seen in the
late, gamma-ray transparent phase are not representative for the early
gamma-ray emission, and rather notice the emission spectrum to be complex and
irregular until the supernova is fully transparent to gamma-rays, with
progressive uncovering of the bulk of 56Ni. We infer that the explosion
morphology is not spherically symmetric, both in the distribution of 56Ni and
of the unburnt material which occults the 56Co emission. Comparing light curves
from different plausible models, the resulting 56Ni mass is determined as
0.49+/-0.09 M_sol.
