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1. 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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2. Evidence of $h_b\left(2\mathrm{P}\right)\to \mathrm{\Upsilon }\left(1\mathrm{S}\right)\eta$ Decay and Search for $h_b(1\mathrm{P},2\mathrm{P})\to \mathrm{\Upsilon }\left(1\mathrm{S}\right){\pi }^0$ with the Belle Detector

   https://doi.org/10.1103/PhysRevLett.133.261901  

   Kovalenko, E; Adachi, I; Aihara, H; Asner, D M; Aushev, T; Ayad, R; Babu, V; Banerjee, Sw; Belous, K; Bennett, J; et al (December 2024, Physical Review Letters)

   We report the first evidence for the $h_b\left(2\mathrm{P}\right)\to \mathrm{\Upsilon }\left(1\mathrm{S}\right)\eta$transition with a significance of 3.5 standard deviations. The decay branching fraction is measured to be $\mathcal{B}\left[h_b\right(2\mathrm{P})\to \mathrm{\Upsilon }(1\mathrm{S}\left)\eta \right]=({7.1}_{-3.2}^{+3.7}\pm 0.8)\times {10}^{-3}$, which is noticeably smaller than expected. We also set upper limits on ${\pi }^0$transitions of $\mathcal{B}\left[h_b\right(2\mathrm{P})\to \mathrm{\Upsilon }(1\mathrm{S}\left){\pi }^0\right]<1.8\times {10}^{-3}$, and $\mathcal{B}\left[h_b\right(1\mathrm{P})\to \mathrm{\Upsilon }(1\mathrm{S}\left){\pi }^0\right]<1.8\times {10}^{-3}$, at the 90% confidence level. These results are obtained with a $131.4{\mathrm{fb}}^{-1}$data sample collected near the $\mathrm{\Upsilon }\left(5\mathrm{S}\right)$resonance with the Belle detector at the KEKB asymmetric-energy $e^{+}{e}^{-}$collider. Published by the American Physical Society2024 

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3. 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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4. First Evidence for Direct $CP$ Violation in Beauty to Charmonium Decays

   https://doi.org/10.1103/PhysRevLett.134.101801  

   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)

   The $CP$asymmetry and branching fraction of the Cabibbo-Kobayashi-Maskawa-suppressed decay $B^{+}\to J/\psi {\pi }^{+}$are precisely measured relative to the favored decay $B^{+}\to J/\psi K^{+}$using a sample of proton-proton collision data corresponding to an integrated luminosity of $5.4{\mathrm{fb}}^{-1}$recorded at a center-of-mass energy of 13 TeV during 2016–2018. The results of the $CP$asymmetry difference and branching fraction ratio are $\mathrm{\Delta }{\mathcal{A}}^{CP}\equiv {\mathcal{A}}^{CP}(B^{+}\to J/\psi {\pi }^{+})-{\mathcal{A}}^{CP}(B^{+}\to J/\psi K^{+})=(1.29\pm 0.49\pm 0.08)\times {10}^{-2}$, ${\mathcal{R}}_{\pi /K}\equiv \left[\mathcal{B}\right(B^{+}\to J/\psi {\pi }^{+})/\mathcal{B}(B^{+}\to J/\psi K^{+}\left)\right]=(3.852\pm 0.022\pm 0.018)\times {10}^{-2}$, where the first uncertainties are statistical and the second are systematic. A combination with previous LHCb results based on data collected at 7 and 8 TeV in 2011 and 2012 yields $\mathrm{\Delta }{\mathcal{A}}^{CP}=(1.42\pm 0.43\pm 0.08)\times {10}^{-2}$and ${\mathcal{R}}_{\pi /K}=(3.846\pm 0.018\pm 0.018)\times {10}^{-2}$. The combined $\mathrm{\Delta }{\mathcal{A}}^{CP}$value deviates from zero by 3.2 standard deviations, providing the first evidence for direct $CP$violation in the amplitudes of beauty decays to charmonium final states. © 2025 CERN, for the LHCb Collaboration2025CERN 

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5. Search for two-body $B$ meson decays to ${\mathrm{\Lambda }}^0$ and ${\mathrm{\Omega }}_c^{(*)0}$

   https://doi.org/10.1103/PhysRevD.110.L031102  

   Savinov, V; Adachi, I; Ahn, J K; Aihara, H; Asner, D M; Atmacan, H; Ayad, R; Banerjee, Sw; Bennett, J; Bessner, M; et al (August 2024, Physical Review D)

   We report the results of the first search for Standard Model and baryon-number-violating two-body decays of the neutral $B$mesons to ${\mathrm{\Lambda }}^0$and ${\mathrm{\Omega }}_c^{(*)0}$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. We observe no evidence of signal from any such decays and set 95% confidence-level upper limits on the products of $B^0$and ${\overline{B}}^0$branching fractions for these two-body decays with $\mathcal{B}({\mathrm{\Omega }}_c^0\to {\pi }^{+}{\mathrm{\Omega }}^{-})$in the range between $9.5\times {10}^{-8}$and $31.2\times {10}^{-8}$. Published by the American Physical Society2024 

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