23rd Conference on Flavor Physics and CP Violation (FPCP 2025)

Analysis of Lambda_b to Lambda(*) nu nu decays in light of recent Belle-II B+-> K+ nu nu data

Not scheduled

20m

Parallel talk

Description

The Belle-II experiment has recently reported the first measurement of $B^{+}\to K^{+}\nu \overline{\nu }$ decay which exceeds the Standard Model prediction by approximately 2.7σ. The deviation may indicate the
presence of new physics beyond the Standard Model in the $b\to s\nu \nu$ sector. Under this assumption, we study the hadronic ${\mathrm{\Lambda }}_b\to \mathrm{\Lambda }(\to p\pi )$and ${\mathrm{\Lambda }}_b\to {\mathrm{\Lambda }}^{\ast }(\to NK)\nu \nu$ decays within both the Standard Model and beyond. We work in a low-energy effective field theory framework with additional light
right-handed neutrinos. We calculate the differential branching ratios of these decay modes and explore the implications of the Belle-II results through various observables.