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1. First Determination of the Spin-Parity of ${\mathrm{\Xi }}_c(3055{)}^{+,0}$ Baryons

   https://doi.org/10.1103/PhysRevLett.134.081901  

   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 (February 2025, Physical Review Letters)

   The ${\mathrm{\Xi }}_b^{0(-)}\to {\mathrm{\Xi }}_c\left(3055{)}^{+\left(0\right)}\right(\to D^{+\left(0\right)}\mathrm{\Lambda }){\pi }^{-}$decay chains are observed, and the spin-parity of ${\mathrm{\Xi }}_c(3055{)}^{+\left(0\right)}$baryons is determined for the first time. The measurement is performed using proton-proton collision data at a center-of-mass energy of $\sqrt{s}=13\mathrm{TeV}$, corresponding to an integrated luminosity of $5.4{\mathrm{fb}}^{-1}$, recorded by the LHCb experiment between 2016 and 2018. The spin-parity of the ${\mathrm{\Xi }}_c(3055{)}^{+\left(0\right)}$baryons is determined to be $3/2^{+}$with a significance of more than $6.5\sigma$( $3.5\sigma$) compared to all other tested hypotheses. The up-down asymmetries of the ${\mathrm{\Xi }}_b^{0(-)}\to {\mathrm{\Xi }}_c(3055{)}^{+\left(0\right)}{\pi }^{-}$transitions are measured to be $-0.92\pm 0.10\pm 0.05$( $-0.92\pm 0.16\pm 0.22$), consistent with maximal parity violation, where the first uncertainty is statistical and the second is systematic. These results support the hypothesis that the ${\mathrm{\Xi }}_c(3055{)}^{+\left(0\right)}$baryons correspond to the first $D$-wave $\lambda$-mode excitation of the ${\mathrm{\Xi }}_c$flavor triplet. © 2025 CERN, for the LHCb Collaboration2025CERN 

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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 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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4. Observation of the $\mathrm{\Upsilon }\left(3S\right)$ Meson and Suppression of $\mathrm{\Upsilon }$ States in Pb-Pb Collisions at $\sqrt{s_{NN}}=5.02\mathrm{TeV}$

   https://doi.org/10.1103/PhysRevLett.133.022302  

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

   The production of $\mathrm{\Upsilon }\left(2S\right)$and $\mathrm{\Upsilon }\left(3S\right)$mesons in lead-lead (Pb-Pb) and proton-proton ( $pp$) collisions is studied in their dimuon decay channel using the CMS detector at the LHC. The $\mathrm{\Upsilon }\left(3S\right)$meson is observed for the first time in Pb-Pb collisions, with a significance above 5 standard deviations. The ratios of yields measured in Pb-Pb and $pp$collisions are reported for both the $\mathrm{\Upsilon }\left(2S\right)$and $\mathrm{\Upsilon }\left(3S\right)$mesons, as functions of transverse momentum and Pb-Pb collision centrality. These ratios, when appropriately scaled, are significantly less than unity, indicating a suppression of $\mathrm{\Upsilon }$yields in Pb-Pb collisions. This suppression increases from peripheral to central Pb-Pb collisions. Furthermore, the suppression is stronger for $\mathrm{\Upsilon }\left(3S\right)$mesons compared to $\mathrm{\Upsilon }\left(2S\right)$mesons, extending the pattern of sequential suppression of quarkonium states in nuclear collisions previously seen for the $J/\psi$, $\psi \left(2S\right)$, $\mathrm{\Upsilon }\left(1S\right)$, and $\mathrm{\Upsilon }\left(2S\right)$mesons. © 2024 CERN, for the CMS Collaboration2024CERN 

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5. 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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