Study of b-hadron decays to Λc+h−h′− final states

Abstract

Abstract Decays of $$ {\Xi}_b^{-} $$ Ξ b −

and $$ {\Omega}_b^{-} $$

Ω b −

baryons to $$ {\Lambda}_c^{+}{h}^{-}{h}^{\prime -} $$

Λ c +

h −

h

′ −

final states, with h−h′− being π−π−, K−π− and K−K− meson pairs, are searched for using data collected with the LHCb detector. The data sample studied corresponds to an integrated luminosity of 8.7 fb−1 of pp collisions collected at centre-of-mass energies $$ \sqrt{s} $$

s

= 7, 8 and 13 TeV. The products of the relative branching fractions and fragmentation fractions for each signal mode, relative to the $$ {B}^{-}\to {\Lambda}_c^{+}\overline{p}{\pi}^{-} $$

B −

→

Λ c +

p ¯

π −

mode, are measured, with $$ {\Xi}_b^{-}\to {\Lambda}_c^{+}{K}^{-}{\pi}^{-} $$

Ξ b −

→

Λ c +

K −

π −

, $$ {\Xi}_b^{-}\to {\Lambda}_c^{+}{K}^{-}{K}^{-} $$

Ξ b −

→

Λ c +

K −

K −

and $$ {\varOmega}_b^{-}\to {\Lambda}_c^{+}{K}^{-}{K}^{-} $$

Ω b −

→

Λ c +

K −

K −

decays being observed at over 5 σ significance. The $$ {\Xi}_b^{-}\to {\Lambda}_c^{+}{K}^{-}{\pi}^{-} $$

Ξ b −

→

Λ c +

K −

π −

mode is also used to measure the $$ {\Xi}_b^{-} $$

Ξ b −

production asymmetry, which is found to be consistent with zero. In addition, the $$ {B}^{-}\to {\Lambda}_c^{+}\overline{p}{K}^{-} $$

B −

→

Λ c +

p ¯

K −

decay is observed for the first time, and its branching fraction is measured relative to that of the $$ {B}^{-}\to {\Lambda}_c^{+}\overline{p}{\pi}^{-} $$

B −

→

Λ c +

p ¯

π −

mode.