In:
The European Physical Journal C, Springer Science and Business Media LLC, Vol. 84, No. 6 ( 2024-06-05)
Abstract:
The decays $${{\varLambda } ^0_{b}} \!\rightarrow {{\varLambda } ^+_{c}} {\hspace{1.79993pt}\overline{\hspace{-1.79993pt}D}} {}^{(*)0}{{K} ^-} $$ Λ b 0 → Λ c + D ¯ ( ∗ ) 0 K - and $${{\varLambda } ^0_{b}} \!\rightarrow {{\varLambda } ^+_{c}} {{D} ^{*-}_{s}} $$ Λ b 0 → Λ c + D s ∗ - are observed for the first time, in proton-proton collision data at $$\sqrt{s} =13\text {Te\hspace{-1.00006pt}V} $$ s = 13 Te V , corresponding to an integrated luminosity of 5.4 $$\text {fb} ^{-1}$$ fb - 1 collected with the LHCb detector. Their ratios of branching fractions with respect to the $${{\varLambda } ^0_{b}} \!\rightarrow {{\varLambda } ^+_{c}} {{D} ^-_{s}} $$ Λ b 0 → Λ c + D s - mode are measured to be $$\begin{aligned} \begin{aligned} \frac{\mathcal {B}\left( {{\varLambda } ^0_{b}} \!\rightarrow {{\varLambda } ^+_{c}} {{\hspace{1.79993pt}\overline{\hspace{-1.79993pt}D}} {}^0} {{K} ^-} \right) }{\mathcal {B}\left( {{\varLambda } ^0_{b}} \!\rightarrow {{\varLambda } ^+_{c}} {{D} ^-_{s}} \right) } & = 0.1908 {}_{-0.0034}^{+0.0036} {}_{-0.0018}^{+0.0016} \pm 0.0038,\\ \frac{\mathcal {B}\left( {{\varLambda } ^0_{b}} \!\rightarrow {{\varLambda } ^+_{c}} {{\hspace{1.79993pt}\overline{\hspace{-1.79993pt}D}} {}^{*0}} {{K} ^-} \right) }{\mathcal {B}\left( {{\varLambda } ^0_{b}} \!\rightarrow {{\varLambda } ^+_{c}} {{D} ^-_{s}} \right) } & = 0.589 {}_{-0.017}^{+0.018} {}_{-0.018}^{+0.017} \pm 0.012,\\ \frac{\mathcal {B}\left( {{\varLambda } ^0_{b}} \!\rightarrow {{\varLambda } ^+_{c}} {{D} ^{*-}_{s}} \right) }{\mathcal {B}\left( {{\varLambda } ^0_{b}} \!\rightarrow {{\varLambda } ^+_{c}} {{D} ^-_{s}} \right) } & = 1.668 \pm 0.022 {}_{-0.055}^{+0.061}, \end{aligned} \end{aligned}$$ B Λ b 0 → Λ c + D ¯ 0 K - B Λ b 0 → Λ c + D s - = 0.1908 - 0.0034 + 0.0036 - 0.0018 + 0.0016 ± 0.0038 , B Λ b 0 → Λ c + D ¯ ∗ 0 K - B Λ b 0 → Λ c + D s - = 0.589 - 0.017 + 0.018 - 0.018 + 0.017 ± 0.012 , B Λ b 0 → Λ c + D s ∗ - B Λ b 0 → Λ c + D s - = 1.668 ± 0.022 - 0.055 + 0.061 , where the first uncertainties are statistical, the second systematic, and the third, for the $${{\varLambda } ^0_{b}} \!\rightarrow {{\varLambda } ^+_{c}} {\hspace{1.79993pt}\overline{\hspace{-1.79993pt}D}} {}^{(*)0}{{K} ^-} $$ Λ b 0 → Λ c + D ¯ ( ∗ ) 0 K - decays, are due to the uncertainties on the branching fractions of the $${{D} ^-_{s}} \!\rightarrow {{K} ^-} {{K} ^+} {{\pi } ^-} $$ D s - → K - K + π - and $${{\hspace{1.79993pt}\overline{\hspace{-1.79993pt}D}} {}^0} \!\rightarrow {{K} ^+} {{\pi } ^-} $$ D ¯ 0 → K + π - decay modes. The measured branching fractions probe factorization assumptions in effective theories and provide the normalization for future pentaquark searches in $${{\varLambda } ^0_{b}} \!\rightarrow {{\varLambda } ^+_{c}} {\hspace{1.79993pt}\overline{\hspace{-1.79993pt}D}} {}^{(*)0}{{K} ^-} $$ Λ b 0 → Λ c + D ¯ ( ∗ ) 0 K - decay channels.
Type of Medium:
Online Resource
ISSN:
1434-6052
DOI:
10.1140/epjc/s10052-024-12752-3
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2024
detail.hit.zdb_id:
1459069-4
Permalink