First observation and branching fraction measurement of the Λ b 0 → D s − p $$ {\Lambda}_b^0\to {D}_s^{-}p $$ decay

Abstract

Abstract

The first observation of the

Λ b 0

→

D s −

p

$$ {\Lambda}_b^0\to {D}_s^{-}p $$ decay is presented using proton-proton collision data collected by the LHCb experiment at a centre-of-mass energy of

s

$$ \sqrt{s} $$ = 13 TeV, corresponding to a total integrated luminosity of 6 fb−1. Using the

Λ b 0

→

Λ c +

π −

$$ {\Lambda}_b^0\to {\Lambda}_c^{+}{\pi}^{-} $$ decay as the normalisation mode, the branching fraction of the

Λ b 0

→

D s −

p

$$ {\Lambda}_b^0\to {D}_s^{-}p $$ decay is measured to be

B

Λ b 0

→

D s −

p

=

12.6 ± 0.5 ± 0.3 ± 1.2

×

10

− 6

$$ \mathcal{B}\left({\Lambda}_b^0\to {D}_s^{-}p\right)=\left(12.6\pm 0.5\pm 0.3\pm 1.2\right)\times {10}^{-6} $$ , where the first uncertainty is statistical, the second systematic and the third due to uncertainties in the branching fractions of the

Λ b 0

→

Λ c +

π −

$$ {\Lambda}_b^0\to {\Lambda}_c^{+}{\pi}^{-} $$ ,

D s −

→

K −

K +

π −

$$ {D}_s^{-}\to {K}^{-}{K}^{+}{\pi}^{-} $$ and

Λ c +

→ p

K −

π +

$$ {\Lambda}_c^{+}\to p{K}^{-}{\pi}^{+} $$ decays.