ICHEP2018 SEOUL

Search for the rare decay B→Λp¯νν¯

5 Jul 2018, 14:20

20m

102 (COEX, Seoul)

Parallel Quark and Lepton Flavor Physics Quark and Lepton Flavor Physics

Speaker

Robert Seddon (McGill University)

Description

We search for the rare flavor-changing neutral current process $B^{-}\to \mathrm{\Lambda }\overline{p}\nu \overline{\nu }$ using data from the BABAR experiment. A total of 424fb${}^{-1}$ of $e^{+}{e}^{-}$ collision data collected at the center-of-mass energy of the $\mathrm{{\rm Y}}(4S)$ resonance is used in this study, corresponding to a sample of $(471\pm 3)\times {10}^6$ $B-\overline{B}$ pairs. Signal $B^{-}\to \mathrm{\Lambda }\overline{p}\nu \overline{nu}$ candidates are identified by first exclusively reconstructing a $B^{+}$ decay in one of many possible decays to hadronic final states, then examining detector activity that is not associated with this reconstructed $B^{-}$ decay for evidence of a signal decay. The data yield is found to be consistent with the expected background contribution under a null signal hypothesis, resulting in an estimated branching fraction of $\mathcal{B}\mathcal{(}{\mathcal{B}}^{\mathcal{-}}\to \mathcal{\Lambda }\overline{\mathcal{p}}\nu \overline{\nu }\mathcal{)}\mathcal{=}\mathcal{(}\mathcal{0.4}\pm \mathcal{1.1}\pm \mathcal{0.6}\mathcal{)}\times {\mathcal{10}}^{\mathcal{-}\mathcal{5}}$, where the uncertainties are statistical and systematic, respectively. An upper limit of $\mathcal{B}\mathcal{(}{\mathcal{B}}^{\mathcal{-}}\to \mathcal{\Lambda }\overline{\mathcal{p}}\nu \overline{\nu }\mathcal{)}\mathcal{<}\mathcal{3.0}\times {\mathcal{10}}^{\mathcal{-}\mathcal{5}}$ at the $90\mathrm{\%}$ confidence level is determined.

Presentation materials

talk.pdf