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1. Searches for $B^0\to K^{+}{\pi }^{-}{\tau }^{+}{\tau }^{-}$ and $B_s^0\to K^{+}{K}^{-}{\tau }^{+}{\tau }^{-}$ Decays

   https://doi.org/10.1103/y968-44v8  

   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 (May 2026, Physical Review Letters)

   The first searches for $B^0\to K^{+}{\pi }^{-}{\tau }^{+}{\tau }^{-}$ and $B_s^0\to K^{+}{K}^{-}{\tau }^{+}{\tau }^{-}$ decays at the LHCb experiment are conducted with $pp$ collision data corresponding to an integrated luminosity of $5.4{\mathrm{fb}}^{-1}$ . The tau leptons are reconstructed using the ${\tau }^{+}\to {\mu }^{+}{\overline{\nu }}_{\tau }{\nu }_{\mu }$ decay and the results are presented in bins of $K^{+}{\pi }^{-}$ or $K^{+}{K}^{-}$ mass. No signal is observed and upper limits are set on the branching fractions. The searches result in the first upper limits for $B^0\to K^{+}{\pi }^{-}{\tau }^{+}{\tau }^{-}$ decays outside the $K^{*}(892{)}^0$ region in $K^{+}{\pi }^{-}$ mass and the first limits for $B_s^0\to K^{+}{K}^{-}{\tau }^{+}{\tau }^{-}$ decays. The searches are recast into limits on the decays $B^0\to K^{*}(892{)}^0{\tau }^{+}{\tau }^{-}$ and $B_s^0\to \varphi \left(1020\right){\tau }^{+}{\tau }^{-}$ , yielding $2.8\times {10}^{-4}$ ( $2.5\times {10}^{-4}$ ) and $4.7\times {10}^{-4}$ ( $4.1\times {10}^{-4}$ ) at the 95% (90%) confidence level, respectively. For the decay $B^0\to K^{*}(892{)}^0{\tau }^{+}{\tau }^{-}$ , this result improves on the current best upper limit by an order of magnitude. 

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2. Search for $B^0\to K^{*0}{\tau }^{+}{\tau }^{-}$ Decays at the Belle II Experiment

   https://doi.org/10.1103/v1q3-9dy8  

   Adachi, I; Adamczyk, K; Aggarwal, L; Ahmed, H; Aihara, H; Akopov, N; Alhakami, M; Aloisio, A; Althubiti, N; Angelsmark, M; et al (October 2025, Physical Review Letters)

   We present a search for the rare flavor-changing neutral-current decay $B^0\to K^{*0}{\tau }^{+}{\tau }^{-}$ with data collected by the Belle II experiment at the SuperKEKB electron-positron collider. The analysis uses a $365{\mathrm{fb}}^{-1}$ data sample recorded at the center-of-mass energy of the $\mathrm{\Upsilon }\left(4S\right)$ resonance. One of the $B$ mesons produced in the $\mathrm{\Upsilon }\left(4S\right)\to B^0{\overline{B}}^0$ process is fully reconstructed in a hadronic decay mode, while its companion $B$ meson is required to decay into a $K^{*0}$ and two $\tau$ leptons of opposite charge. The $\tau$ leptons are reconstructed in final states with a single electron, muon, charged pion or charged $\rho$ meson, and additional neutrinos. We set an upper limit on the branching fraction of $\mathcal{B}\left(B^0\to K^{*0}{\tau }^{+}{\tau }^{-}\right)<1.8\times {10}^{-3}$ at the 90% confidence level, which is the most stringent constraint reported to date. 

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3. Comprehensive Analysis of the $B^0\to K^{*0}{\mu }^{+}{\mu }^{-}$ Decay

   https://doi.org/10.1103/24g9-yn9d  

   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 (July 2026, Physical Review Letters)

   An analysis of the $B^0\to K^{*0}(\to K^{+}{\pi }^{-}){\mu }^{+}{\mu }^{-}$ decay is presented using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of $8.4{\mathrm{fb}}^{-1}$ . The full set of $CP$ -averaged and $CP$ -asymmetric angular observables is determined in bins of the invariant mass squared of the dimuon system, as well as the branching fraction relative to the $B^0\to J/\psi (\to {\mu }^{+}{\mu }^{-})K^{+}{\pi }^{-}$ decay. For the first time, the full set of observables pertaining to the $K^{+}{\pi }^{-}$ S-wave contribution to the final state are presented and consideration is given to effects arising from the mass of the muons. The extracted $CP$ -asymmetry observables show no significant deviations from zero. The measurements of the $CP$ -averaged observables and the branching fractions continue to exhibit the pattern of tensions with the standard model predictions that have been seen in previous analyses that use part of the dataset considered in this Letter. 

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4. Observation of the Open-Charm Tetraquark Candidate $T_{cs0}^{*}(2870{)}^0$ in the $B^{-}\to D^{-}{D}^0{K}_S^0$ Decay

   https://doi.org/10.1103/PhysRevLett.134.101901  

   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)

   An amplitude analysis of $B^{-}\to D^{-}{D}^0{K}_S^0$ decays is performed using proton-proton collision data, corresponding to an integrated luminosity of $9{\mathrm{fb}}^{-1}$ , collected with the LHCb detector at center-of-mass energies of 7, 8, and 13 TeV. A resonant structure of spin-parity $0^{+}$ is observed in the $D^0{K}_S^0$ invariant-mass spectrum with a significance of $5.3\sigma$ . The mass and width of the state, modeled with a Breit-Wigner line shape, are determined to be $2883\pm 11\pm 8\mathrm{MeV}/c^2$ and ${87}_{-47}^{+22}\pm 17\mathrm{MeV}$ , respectively, where the first uncertainties are statistical and the second systematic. These properties and the quark content are consistent with those of the open-charm tetraquark candidate $T_{cs0}^{*}(2870{)}^0$ observed previously in the $D^{+}{K}^{-}$ final state of the $B^{-}\to D^{-}{D}^{+}{K}^{-}$ decay. This result confirms the existence of the $T_{cs0}^{*}(2870{)}^0$ state in a new decay mode. The $T_{cs1}^{*}(2900{)}^0$ state, reported in the $B^{-}\to D^{-}{D}^{+}{K}^{-}$ decay, is also searched for in the $D^0{K}_S^0$ invariant-mass spectrum of the $B^{-}\to D^{-}{D}^0{K}_S^0$ decay, without finding evidence for it. © 2025 CERN, for the LHCb Collaboration2025CERN 

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5. $K^{*}{\left(892\right)}^0$ and $\varphi \left(1020\right)$ production at midrapidity in $pp$ collisions at $\sqrt{s}=8$ TeV

   https://doi.org/10.1103/PhysRevC.102.024912  

   Acharya, S.; Adamová, D.; Adhya, S. P.; Adler, A.; Adolfsson, J.; Aggarwal, M. M.; Aglieri Rinella, G.; Agnello, M.; Agrawal, N.; Ahammed, Z.; et al (August 2020, Physical Review C)

   null (Ed.)