When energy goes missing: new physics in $$b\rightarrow s \nu \nu $$ with sterile neutrinos

Abstract

AbstractBelle II recently reported the first measurement of $$B^+\rightarrow K^+ + \textrm{inv}$$ B + → K + + inv , which is $$2.8\sigma $$ 2.8 σ above the Standard Model prediction. We explore the available parameter space of new physics within Standard Model effective field theory extended by sterile neutrinos ($$\nu $$ ν SMEFT) and provide predictions for the other $$B\rightarrow K^{(\star )} +\textrm{inv}$$ B → K ( ⋆ ) + inv decay modes and invisible $$B_s$$ B s decays. We also briefly comment on charged current decays $$B\rightarrow D^{(\star )} \ell \bar{\nu }$$ B → D ( ⋆ ) ℓ ν ¯ and possible ultraviolet completions of the relevant $$\nu $$ ν SMEFT operators.