  The di-leptons and di-neutrinos observed in the final states of
flavor-changing neutral b decays provide an ideal platform for probing physics
beyond the standard model. Although the latest measurements of $R_{K^{(*)}}$
agree well with the standard model prediction, there exists several other
observables such as $P_5^{\prime}$, $\mathcal{B}(B_s\to \phi \mu^{+}\mu^{-})$
and $\mathcal{B}(B_s\to \mu^{+}\mu^{-})$ in $b\to s \ell\ell$ transition decays
that shows deviation from the standard model prediction. Similalry, very
recently Belle II collaboration reported a more precise upper bound of
$\mathcal{B}(B\to K^+\nu\bar{\nu}) < 4.1\times 10^{-5}$ by employing a new
inclusive tagging approach and it also deviates from the standard model
expectation. The $b\to s l^{+}l^{-}$ and $b\to s\nu\bar{\nu}$ transition decays
are related not only in the standard model but also in beyond the standard
model physics due to $SU(2)_L$ gauge symmetry, and can be most effectively
investigated using the standard model effective field theory formalism.
Additionally, the $b\to s\nu\bar{\nu}$ decay channels are theoretically cleaner
than the corresponding $b\to s l^{+}l^{-}$ decays, as these processes do not
get contributions from non-factorizable corrections and photonic penguin
contributions. In this context, we study $\Lambda_b\to (\Lambda^*(\to pK^-),
\Lambda(\to p\pi))({\mu}^{+}\mu^{-},\,\nu\bar{\nu})$ baryonic decays undergoing
$b\to s \ell^{+}\ell^{-}$ and $b\to s\nu\bar{\nu}$ quark level transitions in a
standard model effective field theory formalism. We give predictions of several
observables pertaining to these decay channels in the standard model and in
case of several new physics scenarios.
