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1. Measurement of ${\mathrm{\Lambda }}_b^0$ , ${\mathrm{\Lambda }}_c^{+}$ , and $\mathrm{\Lambda }$ Decay Parameters Using ${\mathrm{\Lambda }}_b^0\to {\mathrm{\Lambda }}_c^{+}{h}^{-}$ Decays

   https://doi.org/10.1103/PhysRevLett.133.261804  

   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 (December 2024, Physical Review Letters)

   A comprehensive study of the angular distributions in the bottom-baryon decays ${\mathrm{\Lambda }}_b^0\to {\mathrm{\Lambda }}_c^{+}{h}^{-}(h=\pi ,K)$ , followed by ${\mathrm{\Lambda }}_c^{+}\to \mathrm{\Lambda }{h}^{+}$ with $\mathrm{\Lambda }\to p{\pi }^{-}$ or ${\mathrm{\Lambda }}_c^{+}\to p{K}_{\mathrm{S}}^0$ decays, is performed using a data sample of proton-proton collisions corresponding to an integrated luminosity of $9{\mathrm{fb}}^{-1}$ collected by the LHCb experiment at center-of-mass energies of 7, 8, and 13 TeV. The decay parameters and the associated charge-parity ( $CP$ ) asymmetries are measured, with no significant $CP$ violation observed. For the first time, the ${\mathrm{\Lambda }}_b^0\to {\mathrm{\Lambda }}_c^{+}{h}^{-}$ decay parameters are measured. The most precise measurements of the decay parameters $\alpha$ , $\beta$ , and $\gamma$ are obtained for ${\mathrm{\Lambda }}_c^{+}$ decays and an independent measurement of the decay parameters for the strange-baryon $\mathrm{\Lambda }$ decay is provided. The results deepen our understanding of weak decay dynamics in baryon decays. © 2024 CERN, for the LHCb Collaboration2024CERN 

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2. 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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3. Measurement of the fraction of jet longitudinal momentum carried by ${\mathrm{\Lambda }}_c^{+}$ baryons in $pp$ collisions

   https://doi.org/10.1103/PhysRevD.109.072005  

   Acharya, S; Adamová, D; Adler, A; Aglieri_Rinella, G; Agnello, M; Agrawal, N; Ahammed, Z; Ahmad, S; Ahn, S U; Ahuja, I; et al (April 2024, Physical Review D)

   Recent measurements of charm-baryon production in hadronic collisions have questioned the universality of charm-quark fragmentation across different collision systems. In this work the fragmentation of charm quarks into charm baryons is probed, by presenting the first measurement of the longitudinal jet momentum fraction carried by ${\mathrm{\Lambda }}_c^{+}$ baryons, $z_{\parallel }^{\mathrm{ch}}$ , in hadronic collisions. The results are obtained in proton-proton ( $pp$ ) collisions at $\sqrt{s}=13\mathrm{TeV}$ at the LHC, with ${\mathrm{\Lambda }}_c^{+}$ baryons and charged (track-based) jets reconstructed in the transverse momentum intervals of $3\le p_T^{{\mathrm{\Lambda }}_c^{+}}<15\mathrm{GeV}/c$ and $7\le p_T^{\text{jet ch}}<15\mathrm{GeV}/c$ , respectively. The $z_{\parallel }^{\mathrm{ch}}$ distribution is compared to a measurement of ${\mathrm{D}}^0$ -tagged charged jets in $pp$ collisions as well as to 8 simulations. The data hints that the fragmentation of charm quarks into charm baryons is softer with respect to charm mesons, in the measured kinematic interval, as predicted by hadronization models which include color correlations beyond leading-color in the string formation. © 2024 CERN, for the ALICE Collaboration2024CERN 

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4. First measurements of the branching fractions for the decay modes ${\mathrm{\Xi }}_c^0\to \mathrm{\Lambda }\eta$ and ${\mathrm{\Xi }}_c^0\to \mathrm{\Lambda }{\eta }^{\prime }$ and search for the decay ${\mathrm{\Xi }}_c^0\to \mathrm{\Lambda }{\pi }^0$ using Belle and Belle II data

   https://doi.org/10.1103/q4n8-fqj1  

   Abumusabh, M; Adachi, I; Aggarwal, L; Ahmed, H; Ahn, Y; Aihara, H; Akopov, N; Alghamdi, S; Alhakami, M; Aloisio, A; et al (February 2026, Physical Review D)

   Using data samples of $988.4{\mathrm{fb}}^{-1}$ and $427.9{\mathrm{fb}}^{-1}$ collected with the Belle and Belle II detectors, we present a study of the singly Cabibbo-suppressed decays ${\mathrm{\Xi }}_c^0\to \mathrm{\Lambda }\eta$ , $\mathrm{\Lambda }{\eta }^{\prime }$ , and $\mathrm{\Lambda }{\pi }^0$ . We observe the decay  ${\mathrm{\Xi }}_c^0\to \mathrm{\Lambda }\eta$ and find evidence for the decay ${\mathrm{\Xi }}_c^0\to \mathrm{\Lambda }{\eta }^{\prime }$ , with corresponding branching ratios determined to be $\mathcal{B}({\mathrm{\Xi }}_c^0\to \mathrm{\Lambda }\eta )/\mathcal{B}({\mathrm{\Xi }}_c^0\to {\mathrm{\Xi }}^{-}{\pi }^{+})=(4.16\pm 0.91\pm 0.23)\%$ and $\mathcal{B}({\mathrm{\Xi }}_c^0\to \mathrm{\Lambda }{\eta }^{\prime })/\mathcal{B}({\mathrm{\Xi }}_c^0\to {\mathrm{\Xi }}^{-}{\pi }^{+})=(2.48\pm 0.82\pm 0.12)\%$ , respectively. We find no significant signal in the ${\mathrm{\Xi }}_c^0\to \mathrm{\Lambda }{\pi }^0$ decay mode and set an upper limit at the 90% credibility level of $\mathcal{B}({\mathrm{\Xi }}_c^0\to \mathrm{\Lambda }{\pi }^0)/\mathcal{B}({\mathrm{\Xi }}_c^0\to {\mathrm{\Xi }}^{-}{\pi }^{+})<3.5\%$ . Multiplying these ratios by the world-average branching fraction of the normalization channel, $\mathcal{B}({\mathrm{\Xi }}_c^0\to {\mathrm{\Xi }}^{-}{\pi }^{+})=(1.43\pm 0.27)\%$ , we obtain the absolute branching fractions of $\mathcal{B}({\mathrm{\Xi }}_c^0\to \mathrm{\Lambda }\eta )=(5.95\pm 1.30\pm 0.32\pm 1.13)\times {10}^{-4}$ , $\mathcal{B}({\mathrm{\Xi }}_c^0\to \mathrm{\Lambda }{\eta }^{\prime })=(3.55\pm 1.17\pm 0.17\pm 0.68)\times {10}^{-4}$ , and an upper limit at the 90% credibility level on the absolute branching fraction of $\mathcal{B}({\mathrm{\Xi }}_c^0\to \mathrm{\Lambda }{\pi }^0)<5.2\times {10}^{-4}$ . The quoted first and second uncertainties are statistical and systematic, respectively, while the third uncertainties arise from the branching fraction of the normalization mode. These results are consistent with most theoretical predictions and further the understanding of the underlying decay mechanisms. 

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5. Amplitude analysis of the ${\mathrm{\Xi }}_c^{+}\to p{K}^{-}{\pi }^{+}$ decay and ${\mathrm{\Xi }}_c^{+}$ baryon polarization measurement in semileptonic beauty-hadron decays

   https://doi.org/10.1103/gcft-fgp1  

   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 (November 2025, Physical Review D)

   An amplitude analysis of the ${\mathrm{\Xi }}_c^{+}\to p{K}^{-}{\pi }^{+}$ decay together with a measurement of the ${\mathrm{\Xi }}_c^{+}$ polarization vector in semileptonic beauty-hadron decays is presented. The analysis is performed using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of $9{\mathrm{fb}}^{-1}$ . An amplitude model is developed and the resonance fractions as well as two- and three-body decay parameters are reported. A sizeable ${\mathrm{\Xi }}_c^{+}$ polarization is found. A large sensitivity of the ${\mathrm{\Xi }}_c^{+}\to p{K}^{-}{\pi }^{+}$ decay to the polarization is seen, making the amplitude model suitable for ${\mathrm{\Xi }}_c^{+}$ polarization measurements in other systems. 

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