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1. Search for Baryon-Number-Violating Processes in $B^{-}$ Decays to the ${\overline{\mathrm{\Xi }}}_c^0{\overline{\mathrm{\Lambda }}}_c^{-}$ Final State

   https://doi.org/10.1103/PhysRevLett.133.071802  

   Gu, T; Savinov, V; Adachi, I; Aihara, H; Asner, D M; Atmacan, H; Aushev, T; Ayad, R; Banerjee, Sw; Belous, K; et al (August 2024, Physical Review Letters)

   We report the results of the first search for $B^{-}$ decays to the ${\overline{\mathrm{\Xi }}}_c^0{\overline{\mathrm{\Lambda }}}_c^{-}$ final state using $711{\mathrm{fb}}^{-1}$ of data collected at the $\mathrm{\Upsilon }\left(4S\right)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider. The results are interpreted in terms of both direct baryon-number-violating $B^{-}$ decay and ${\mathrm{\Xi }}_c^0-{\overline{\mathrm{\Xi }}}_c^0$ oscillations which follow the standard model decay $B^{-}\to {\mathrm{\Xi }}_c^0{\overline{\mathrm{\Lambda }}}_c^{-}$ . We observe no evidence for baryon number violation and set the 95% confidence-level upper limits on the ratio of baryon-number-violating and standard model branching fractions $\mathcal{B}(B^{-}\to {\overline{\mathrm{\Xi }}}_c^0{\overline{\mathrm{\Lambda }}}_c^{-})/\mathcal{B}(B^{-}\to {\mathrm{\Xi }}_c^0{\overline{\mathrm{\Lambda }}}_c^{-})$ to be $<2.7\%$ and on the effective angular frequency of mixing $\omega$ in ${\mathrm{\Xi }}_c^0-{\overline{\mathrm{\Xi }}}_c^0$ oscillations to be $<0.76{\mathrm{ps}}^{-1}$ (equivalent to ${\tau }_{\mathrm{mix}}>1.3\mathrm{ps}$ ). Published by the American Physical Society2024 

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2. Study of the $B^0\to {\mathrm{\Lambda }}_c^{+}{\overline{\mathrm{\Lambda }}}_c^{-}{K}_S^0$ decay

   https://doi.org/10.1103/jrkb-q3w6  

   Aaij, R; Abdelfatah, M; Abdelmotteleb, A_S W; Abellan_Beteta, C; Abudinén, F; Ackernley, T; Adefisoye, A A; Adeva, B; Adinolfi, M; Adlarson, P; et al (July 2026, Physical Review D)

   The decay $B^0\to {\mathrm{\Lambda }}_c^{+}{\overline{\mathrm{\Lambda }}}_c^{-}{K}_{\mathrm{S}}^0$ is studied at LHCb for the first time using proton-proton collision data recorded by the LHCb experiment at a center-of-mass energy of $\sqrt{s}=13\mathrm{TeV}$ , corresponding to an integrated luminosity of $5.4{\mathrm{fb}}^{-1}$ . The branching ratio relative to the decay $B^{+}\to {\mathrm{\Lambda }}_c^{+}{\overline{\mathrm{\Lambda }}}_c^{-}{K}^{+}$ is measured to be [ $\mathcal{B}(B^0\to {\mathrm{\Lambda }}_c^{+}{\overline{\mathrm{\Lambda }}}_c^{-}{K}_{\mathrm{S}}^0)]/[\mathcal{B}(B^{+}\to {\mathrm{\Lambda }}_c^{+}{\overline{\mathrm{\Lambda }}}_c^{-}{K}^{+})]=0.53\pm 0.05\pm 0.05$ where the first uncertainty is statistical and the second is systematic. Evidence is found for contributions from two resonant states, ${\mathrm{\Xi }}_c(2923{)}^{+}$ and ${\mathrm{\Xi }}_c(2939{)}^{+}$ , in the ${\mathrm{\Lambda }}_c^{+}{K}_{\mathrm{S}}^0$ system. The two states show a significance of $3.9\sigma$ relative to the nonresonant hypothesis. These two ${\mathrm{\Xi }}_c^{+}$ states are consistent with being the isospin partners of the states observed in the ${\mathrm{\Lambda }}_c^{+}{K}^{-}$ system. 

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3. Study of ${\mathrm{\Lambda }}_b^0$ and ${\mathrm{\Xi }}_b^0$ Decays to $\mathrm{\Lambda }{h}^{+}{h}^{\prime -}$ and Evidence for $CP$ Violation in ${\mathrm{\Lambda }}_b^0\to \mathrm{\Lambda }{K}^{+}{K}^{-}$ Decays

   https://doi.org/10.1103/PhysRevLett.134.101802  

   Aaij, R; Abdelmotteleb, A_S W; Abellan_Beteta, C; Abudinén, F; Ackernley, T; Adefisoye, A A; Adeva, B; Adinolfi, M; Adlarson, P; Agapopoulou, C; et al (March 2025, Physical Review Letters)

   A study of ${\mathrm{\Lambda }}_b^0$ and ${\mathrm{\Xi }}_b^0$ decays to $\mathrm{\Lambda }{h}^{+}{h}^{\prime -}$ ( $h^{(\prime )}=\pi ,K$ ) is performed using $pp$ collision data collected by the LHCb experiment during LHC Runs 1–2, corresponding to an integrated luminosity of $9{\mathrm{fb}}^{-1}$ . The branching fractions for these decays are measured using the ${\mathrm{\Lambda }}_b^0\to {\mathrm{\Lambda }}_c^{+}(\to \mathrm{\Lambda }{\pi }^{+}){\pi }^{-}$ decay as a control channel. The decays ${\mathrm{\Lambda }}_b^0\to \mathrm{\Lambda }{\pi }^{+}{\pi }^{-}$ and ${\mathrm{\Xi }}_b^0\to \mathrm{\Lambda }{K}^{-}{\pi }^{+}$ are observed for the first time. For decay modes with sufficient signal yields, $CP$ asymmetries are measured in the full and localized regions of the final-state phase space. Evidence is found for $CP$ violation in the ${\mathrm{\Lambda }}_b^0\to \mathrm{\Lambda }{K}^{+}{K}^{-}$ decay, interpreted as originating primarily from an asymmetric ${\mathrm{\Lambda }}_b^0\to N^{*+}{K}^{-}$ decay amplitude. The measured $CP$ asymmetries for other decays are compatible with zero. © 2025 CERN, for the LHCb Collaboration2025CERN 

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4. Observation of the ${\mathrm{\Xi }}_b^{-}\to \psi \left(2S\right){\mathrm{\Xi }}^{-}$ decay and studies of the ${\mathrm{\Xi }}_b(5945{)}^0$ baryon in proton-proton collisions at $\sqrt{s}=13\mathrm{TeV}$

   https://doi.org/10.1103/PhysRevD.110.012002  

   Hayrapetyan, A; Tumasyan, A; Adam, W; Andrejkovic, J W; Bergauer, T; Chatterjee, S; Damanakis, K; Dragicevic, M; Hussain, P S; Jeitler, M; et al (July 2024, Physical review)

   The first observation of the decay ${\mathrm{\Xi }}_b^{-}\to \psi \left(2S\right){\mathrm{\Xi }}^{-}$ and measurement of the branching ratio of ${\mathrm{\Xi }}_b^{-}\to \psi \left(2S\right){\mathrm{\Xi }}^{-}$ to ${\mathrm{\Xi }}_b^{-}\to J/\psi {\mathrm{\Xi }}^{-}$ are presented. The $J/\psi$ and $\psi \left(2S\right)$ mesons are reconstructed using their dimuon decay modes. The results are based on proton-proton colliding beam data from the LHC collected by the CMS experiment at $\sqrt{s}=13\mathrm{TeV}$ in 2016–2018, corresponding to an integrated luminosity of $140{\mathrm{fb}}^{-1}$ . The branching fraction ratio is measured to be $\mathcal{B}\left({\mathrm{\Xi }}_b^{-}\to \psi \left(2S\right){\mathrm{\Xi }}^{-}\right)/\mathcal{B}\left({\mathrm{\Xi }}_b^{-}\to J/\psi {\mathrm{\Xi }}^{-}\right)=0.84_{-0.19}^{+0.21}\left(\mathrm{stat}\right)\pm 0.10\left(\mathrm{syst}\right)\pm 0.02\left(\mathcal{B}\right)$ , where the last uncertainty comes from the uncertainties in the branching fractions of the charmonium states. New measurements of the ${\mathrm{\Xi }}_b(5945{)}^0$ baryon mass and natural width are also presented, using the ${\mathrm{\Xi }}_b^{-}{\pi }^{+}$ final state, where the ${\mathrm{\Xi }}_b^{-}$ baryon is reconstructed through the decays $J/\psi {\mathrm{\Xi }}^{-}$ , $\psi \left(2S\right){\mathrm{\Xi }}^{-}$ , $J/\psi \mathrm{\Lambda }{K}^{-}$ , and $J/\psi {\mathrm{\Sigma }}^0{K}^{-}$ . Finally, the fraction of ${\mathrm{\Xi }}_b^{-}$ baryons produced from ${\mathrm{\Xi }}_b(5945{)}^0$ decays is determined. © 2024 CERN, for the CMS Collaboration2024CERN 

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5. Search for charmed baryons in the ${\mathrm{\Lambda }}_c^{+}\eta$ system and measurement of the branching fractions of ${\mathrm{\Lambda }}_c(2880{)}^{+}$ and ${\mathrm{\Lambda }}_c(2940{)}^{+}$ decaying to ${\mathrm{\Lambda }}_c^{+}\eta$ and $p{D}^0$ relative to ${\mathrm{\Sigma }}_c\left(2455\right)\pi$

   https://doi.org/10.1103/PhysRevD.110.032021  

   Li, S X; Shen, C P; Adachi, I; Ahn, J K; Aihara, H; Asner, D M; Atmacan, H; Aushev, T; Ayad, R; Banerjee, Sw; et al (August 2024, Physical Review D)

   We search for excited charmed baryons in the ${\mathrm{\Lambda }}_c^{+}\eta$ system using a data sample corresponding to an integrated luminosity of $980{\mathrm{fb}}^{-1}$ . The data were collected by the Belle detector at the KEKB $e^{+}{e}^{-}$ asymmetric-energy collider. No significant signals are found in the ${\mathrm{\Lambda }}_c^{+}\eta$ mass spectrum, including the known ${\mathrm{\Lambda }}_c(2880{)}^{+}$ and ${\mathrm{\Lambda }}_c(2940{)}^{+}$ . Clear ${\mathrm{\Lambda }}_c(2880{)}^{+}$ and ${\mathrm{\Lambda }}_c(2940{)}^{+}$ signals are observed in the $p{D}^0$ mass spectrum. We set upper limits at 90% credibility level on ratios of branching fractions of ${\mathrm{\Lambda }}_c(2880{)}^{+}$ and ${\mathrm{\Lambda }}_c(2940{)}^{+}$ decaying to ${\mathrm{\Lambda }}_c^{+}\eta$ relative to ${\mathrm{\Sigma }}_c\left(2455\right)\pi$ of $<0.13$ for the ${\mathrm{\Lambda }}_c(2880{)}^{+}$ and $<1.11$ for the ${\mathrm{\Lambda }}_c(2940{)}^{+}$ . We measure ratios of branching fractions of ${\mathrm{\Lambda }}_c(2880{)}^{+}$ and ${\mathrm{\Lambda }}_c(2940{)}^{+}$ decaying to $p{D}^0$ relative to ${\mathrm{\Sigma }}_c\left(2455\right)\pi$ of $0.75\pm 0.03\left(\mathrm{stat}\right)\pm 0.07\left(\mathrm{syst}\right)$ for the ${\mathrm{\Lambda }}_c(2880{)}^{+}$ and $3.59\pm 0.21\left(\mathrm{stat}\right)\pm 0.56\left(\mathrm{syst}\right)$ for the ${\mathrm{\Lambda }}_c(2940{)}^{+}$ . Published by the American Physical Society2024 

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