Observation of charmless baryonic decays $B^0_{(s)} \to p \overline{p} h^+ h^{\prime-}$

Information

LHCb-PAPER-2017-005
CERN-EP-2017-052
arXiv:1704.08497 [PDF]

(Submitted on 27 Apr 2017)
Phys. Rev. D96 (2017) 051103
Inspire 1597124

Tools

Abstract

Decays of $B^0$ and $B_{s}^0$ mesons to the charmless baryonic final states $p \overline{p} h^+ h^{\prime-}$, where $h$ and $h^\prime$ each denote a kaon or a pion, are searched for using the LHCb detector. The analysis is based on a sample of proton-proton collision data collected at center-of-mass energies of $7$ and $8 $TeV, corresponding to an integrated luminosity of $3 $fb$^{-1}$. Four-body charmless baryonic $B_{s}^0$ decays are observed for the first time. The decays $B^0_{s}\to p \overline{p} K^+ K^-$, $B^0_{s}\to p \overline{p} K^\pm \pi^\mp$, $B^0\to p \overline{p} K^\pm \pi^\mp$ and $B^0\to p \overline{p} \pi^+\pi^-$ are observed with a significance greater than $5$ standard deviations; evidence at $4.1$ standard deviations is found for the $B^0\to p \overline{p} K^+ K^-$ decay and an upper limit is set on the branching fraction for $B^0_{s}\to p \overline{p} \pi^+ \pi^-$. Branching fractions in the kinematic region $m(p \overline{p})<2850 $MeV$/c^2$ are measured relative to the $B^0 \to J/\psi (\to p \overline{p}) K^*(892)^0$ channel.

Figures and captions

Invariant mass distributions for $ B ^0_{{\scriptscriptstyle (} s {\scriptscriptstyle )}} $ candidates in the (top left) $ p \overline p K K $, (top right) $ p \overline p K \pi $, (bottom left) $ p \overline p \pi \pi $ final state and (bottom right) invariant mass distribution of $ B ^0 \rightarrow { J \mskip -3mu/\mskip -2mu\psi \mskip 2mu} K^*(892)^0$ in the $ p \overline p K \pi $ final state. The results of the fits are shown with blue solid lines. In the first three figures signals for $ B ^0 $ and $ B ^0_ s $ decays are shown, respectively, with green dotted and red dot-dashed lines, combinatorial backgrounds are shown with black dashed lines and cross-feed backgrounds are shown with violet dot-dashed lines. In the bottom right figure the normalization signal is shown with a green dotted line, the $ K \pi $ S-wave component is displayed with a red dot-dashed line and the combinatorial background with a black dashed line.	Fig1a.pdf [23 KiB] HiDef png [277 KiB] Thumbnail [245 KiB] *.C file
	Fig1b.pdf [32 KiB] HiDef png [267 KiB] Thumbnail [232 KiB] *.C file
	Fig1c.pdf [22 KiB] HiDef png [267 KiB] Thumbnail [228 KiB] *.C file
	Fig1d.pdf [21 KiB] HiDef png [263 KiB] Thumbnail [227 KiB] *.C file
Efficiency-corrected and background-subtracted (left) $m( h h^{\prime} )$ and (right) $m( p \overline p )$ distributions from (top) $ B ^0 \rightarrow p \overline p K \pi $, (middle) $ B ^0_ s \rightarrow p \overline p K K $, and (bottom) $ B ^0 \rightarrow p \overline p \pi \pi $ candidates. Events with entries in the charmonium or $D^0$ mass regions have been removed from the samples. All distributions are normalized to unity.	Fig2a.pdf [16 KiB] HiDef png [114 KiB] Thumbnail [69 KiB] *.C file
	Fig2b.pdf [14 KiB] HiDef png [91 KiB] Thumbnail [53 KiB] *.C file
	Fig2c.pdf [17 KiB] HiDef png [117 KiB] Thumbnail [68 KiB] *.C file
	Fig2d.pdf [14 KiB] HiDef png [94 KiB] Thumbnail [54 KiB] *.C file
	Fig2e.pdf [16 KiB] HiDef png [119 KiB] Thumbnail [70 KiB] *.C file
	Fig2f.pdf [14 KiB] HiDef png [93 KiB] Thumbnail [54 KiB] *.C file
Animated gif made out of all figures.	PAPER-2017-005.gif Thumbnail

Tables and captions

Fitted yields, signal yield significances and branching fractions computed using Eq. (1). The uncertainties on the yields are statistical only. The first uncertainty on each branching fraction is statistical, the second systematic, the third comes from the uncertainty on the branching fraction of the normalization mode and the fourth, where present, is due to the uncertainty on $f_d/f_s$.	Table_1.pdf [55 KiB] HiDef png [65 KiB] Thumbnail [29 KiB] tex code
Ratios of branching fractions among different $ B ^0_{{\scriptscriptstyle (} s {\scriptscriptstyle )}} \rightarrow p \overline p h h^{\prime} $ modes. The first uncertainty is statistical, the second systematic and the third, where present, comes from the uncertainty on $f_d/f_s$.	Table_2.pdf [40 KiB] HiDef png [58 KiB] Thumbnail [28 KiB] tex code

Supplementary Material [file]

Supplementary material full pdf	Supple[..].pdf [147 KiB]
This ZIP file contains supplemetary material for the publication LHCb-PAPER-2017-005. The files are: Supplementary.pdf : An overview of the extra figures and tables Sup.pdf, Sup.png, Sup.eps, Sup.C : The figures in various formats TabSup.pdf, TabSup.tex : The tables in various formats	Sup1a.pdf [20 KiB] HiDef png [261 KiB] Thumbnail [225 KiB] *C file
	Sup1b.pdf [21 KiB] HiDef png [263 KiB] Thumbnail [220 KiB] *C file
	TabSup1.pdf [64 KiB] HiDef png [79 KiB] Thumbnail [33 KiB] *C file
	TabSup2.pdf [50 KiB] HiDef png [67 KiB] Thumbnail [24 KiB] *C file