  The experimental search for coherent neutrinoless conversion of muon to
electron in the presence of a nucleus, aims to probe the possibility of charged
lepton flavour violation. The COMET experiment at J-PARC is one such setup
offering unprecedented statistical reach, with single event sensitivities down
to $\mathcal{O}$ ($\mathrm{10^{-17}}$). Its successor experiment - PRISM,
planned as the final stage, is expected to take this bound further down by two
orders of magnitude. The electrons from standard model decay of bound muons are
considered the most formidable physics background to the detection of these
conversion electrons. Keeping in view the high stopped muon statistics for
COMET and PRISM, the rate of charged current interaction of decay neutrinos
with nuclear protons is also non-negligible. In this work, we perform a
calculation of the positron event rates expected due to interactions of
electron antineutrinos with Al target protons in the COMET setup. About
$\mathrm{7\pm1}$ such $\mathrm{e^{+}}$ events per $\mathrm{10^{18}}$stopped
muons are expected.
