Abstract

The first observation of the decay of a $B^0$ meson to a purely baryonic final state, $B^0 \to p \bar{p}$, is reported. The proton-proton collision data sample used was collected with the LHCb experiment at center-of-mass energies of 7 and 8 TeV and corresponds to an integrated luminosity of 3.0 fb$^{-1}$. The branching fraction is determined to be $${\cal B}(B^0 \to p \bar{p}) = ( 1.25 \pm 0.27 \pm 0.18 ) \times 10^{-8} ,$$ where the first uncertainty is statistical and the second systematic. The decay mode $B^0 \to p \bar{p}$ is the rarest decay of the $B^0$ meson observed to date. The decay $B_s^0 \to p \bar{p}$ is also investigated. No signal is seen and the upper limit ${\cal B}(B_s^0 \to p \bar{p}) < 1.5 \times 10^{-8}$ at 90 confidence level is set on the branching fraction.

Figures and captions

Invariant mass distribution of $ p \overline p $ candidates. The fit result (blue, solid line) is shown together with each fit model component: the $ B ^0 \rightarrow p \overline p $ signal (red, dashed line), the $ B ^0_ s \rightarrow p \overline p $ signal (grey, dashed line) and the combinatorial background (green, dotted line).	Fig1.pdf [89 KiB] HiDef png [233 KiB] Thumbnail [183 KiB] *.C file
Invariant mass distribution of $ K ^\pm \pi ^\mp $ candidates. The fit result (blue, solid line) is shown together with each fit model component.	Fig2.pdf [169 KiB] HiDef png [336 KiB] Thumbnail [232 KiB] *.C file
Animated gif made out of all figures.	PAPER-2017-022.gif Thumbnail

Supplementary Material [file]

Supplementary material full pdf	supple[..].pdf [249 KiB]
This ZIP file contains supplementary material for the publication LHCb-PAPER-2017-022. The files are: - The PDF file with the supplementary material itself. - All figures in numerous formats.	Fig3.pdf [146 KiB] HiDef png [239 KiB] Thumbnail [186 KiB] *C file
	Fig4.pdf [14 KiB] HiDef png [134 KiB] Thumbnail [105 KiB] *C file

Created on 04 May 2024.