  A theoretical formalism of Andreev reflection is employed to provide
theoretical support for distinguishing between the singlet pairing and the
triplet pairing by the point contact Andreev reflection (PCAR) experiments. We
utilize our theoretical curves to fit the data of the PCAR experiment on
unconventional superconductivity in the Bi/Ni bilayer [arXiv:1810.10403] and
find the Anderson-Brinkman-Morel (ABM) state satisfies the main characteristics
of the experimental data. The chiral cross-section of the ABM state might
explain well the broken time-reversal symmetry determined by the polar Kerr
effect measurements and the time-domain THz spectroscopy in Bi/Ni bilayers.
Moreover, the Andreev reflection spectra of the Balian-Werthamer state and the
chiral $p$-wave state are also presented.
