  We investigate explosive nucleosynthesis in a non-rotating 15$M_\odot$ star
with solar metallicity that explodes by a neutrino-heating supernova (SN)
mechanism aided by both standing accretion shock instability (SASI) and
convection. To trigger explosions in our two-dimensional hydrodynamic
simulations, we approximate the neutrino transport with a simple light-bulb
scheme and systematically change the neutrino fluxes emitted from the
protoneutron star. By a post-processing calculation, we evaluate abundances and
masses of the SN ejecta for nuclei with the mass number $\le 70$ employing a
large nuclear reaction network. Aspherical abundance distributions, which are
observed in nearby core-collapse SN remnants, are obtained for the non-rotating
spherically-symmetric progenitor, due to the growth of low-mode SASI. Abundance
pattern of the supernova ejecta is similar to that of the solar system for
models whose masses ranges $(0.4-0.5) \Ms$ of the ejecta from the inner region
($\le 10,000\km$) of the precollapse core. For the models, the explosion
energies and the \nuc{Ni}{56} masses are $ \simeq 10^{51} \rm erg$ and
$(0.05-0.06) \Ms$, respectively; their estimated baryonic masses of the neutron
star are comparable to the ones observed in neutron-star binaries. These
findings may have little uncertainty because most of the ejecta is composed by
matter that is heated via the shock wave and has relatively definite
abundances. The abundance ratios for Ne, Mg, Si and Fe observed in Cygnus loop
are well reproduced with the SN ejecta from an inner region of the $15\Ms$
progenitor.
