$Λ_b\toΛ^{(*)}ν{\barν}$ and $b\to s$ $B$ decays

The baryonic $b\to s$ transition $Λ_b\toΛ^{(*)}ν{\barν}$ is analyzed. We combine the mesonic counterpart $B^+\to K^+ν{\barν}$ and $B^0\to K^{*0}ν{\barν}$ as well as other observables involving $B$ mesons like $R(K^{(*)})$, ${\rm Br}(B_s\toμ^+μ^-)$, ${\rm Br}(B^+\to K^+μ^+μ^-)$, and $P_5'(B^+\to K^{*+}μ^+μ^-)$. We find that the new physics scale $M_{\rm NP}$ to be $2.04~{\rm TeV}\le M_{\rm NP} \le 11.76~{\rm TeV}$ (at $1σ$) for ordinary heavy new mediators. Our predictions for the branching ratios ${\rm Br}(Λ_b\toΛ^{(*)}ν{\barν})$ are $2.07 (1.07)$ times the standard model estimations, which could be verified at future colliders.