Merna Abumusabh ; Giulio DUJANY ; Jacopo CERASOLI

2024
IPHC Strasbourg

Abstract: This work presents the search for the decay of a charged B-meson into a charged kaon and a pair of neutrinos via graph-tagged analysis, which is an approach based on graph neural network, in Belle~II, which is operating at the asymmetric electron-positron collider SuperKEKB located at KEK, Tsukuba, Japan. B+ -> K+ nu nubar is a flavour changing neutral-current process that is highly suppressed in the Standard Model, and imposes many experimental challenge posed by the undetected pair of neutrinos in its final state. However, its branching fraction is accurately predicted in the Standard Model of particle physics, thus, a precise measurement of this branching fraction offers a unique opportunity to probe beyond Standard Model contributions. The expected upper limit on the branching fraction of B+ -> K+ nu nubar is determined to be 0.987* 10^{-5} at 90% confidence level, using simulated events.

Note: Presented on 19 06 2024
Note: MSc