The influence of invisible light particles on ${\Lambda }_b\to \Lambda E_{\mathrm{miss}}$

Abstract

In this work, we study the contribution of invisible light particles to ${\Lambda }_b\to \Lambda E_{\mathrm{miss}}$, particularly the three-body decays ${\Lambda }_b\to \Lambda \varphi \bar{\varphi }$ and ${\Lambda }_b\to \Lambda \psi \bar{\psi }$. The differential branching ratio of ${\Lambda }_b\to \Lambda E_{\mathrm{miss}}$ and the $q^2$-dependent longitudinal polarization asymmetry of $\Lambda$ in scenarios explaining the Belle II excess are presented. In the chiral basis, we investigate the correlations between $\mathcal{B}(B\to K{E}_{\mathrm{miss}})$ and $\mathcal{B}({\Lambda }_b\to \Lambda E_{\mathrm{miss}})$, as well as between $\mathcal{B}(B\to K{E}_{\mathrm{miss}})$ and $P_L^{\Lambda }$, in eight distinct new physics scenarios. We find that the $P_L^{\Lambda }$ can be used to distinguish the chirality of the hadronic current part in the effective operators, which is similar to the cases in the two-body decays ${\Lambda }_b\to \Lambda \varphi$ and ${\Lambda }_b\to \Lambda V$.

Comments: 7 pages, 3 figures, 1 table