Bottomed baryon decays with invisible Majorana fermions

Abstract

We study the invisible Majorana fermions of $\chi$ in bottomed baryon decays with flavor-changing neutral currents (FCNCs) based on the model-independent effective Lagrangian between the quarks and invisible particles. From the bounds of the coupling constants extracted from the experiments, we examine the decay branching ratios of ${\Lambda }_b\to \Lambda \chi \chi$, ${\Xi }_b^{0(-)}\to {\Xi }^{0(-)}\chi \chi$, ${\Lambda }_b\to n\chi \chi$, ${\Xi }_b^{-}\to {\Sigma }^{-}\chi \chi$, ${\Xi }_b^0\to {\Sigma }^0\chi \chi$, and ${\Xi }_b^0\to \Lambda \chi \chi$, which can be as large as $6.3,9.2,5.7,5.8,2.7$, and $1.0\times 10^{-5}$ for $m_{\chi }=2$ GeV, respectively. Some of these decays are accessible to the future experimental searches, such as Belle II.

Comments: 18 pages, 29 figures