Observation of the decay $$ {B}_s^0\to {K}^0p\overline{p} $$ and measurement of the $$ {B}_{(s)}^0\to {K}^0p\overline{p} $$ branching fractions

Abstract

Abstract A study of the charmless baryonic decays

$$ {B}_{(s)}^0\to {K}^0p\overline{p} $$

B

s

0

→

K 0

p

p ¯

is presented, where

$$ {B}_{(s)}^0 $$

B

s

0

denotes either a B 0 or a

$$ {B}_s^0 $$

B s 0

meson. The analysis is based on proton-proton collision data collected by the LHCb experiment at centre-of-mass energies of 7, 8, and 13 TeV, corresponding to an integrated luminosity of 9 fb −1. The decay

$$ {B}_s^0\to {K}^0p\overline{p} $$

B s 0

→

K 0

p

p ¯

is observed for the first time, with a measured branching fraction of (9.14 ± 1.69 ± 0.90 ± 0.33 ± 0.20) × 10 −7 and a significance of 5.6σ. The uncertainties respectively account for statistical and systematic contributions, the precision of the branching fraction of the normalisation channel B 0 → K 0 π + π

− and the fragmentation fraction ratio f

s

/f

d . The branching fraction determined for

$$ {B}^0\to {K}^0p\overline{p} $$

B 0

→

K 0

p

p ¯

is (2.82 ± 0.08 ± 0.12 ± 0.10) × 10 −6, which is the most precise measurement to date.