LHCb Physics

Branching fraction measurement of the decay B⁺→ψ(2S)ϕ(1020)K⁺ arxiv.org/abs/2503.02711 - Using the world-average branching fraction for B⁺→J/ψϕ(1020)K⁺, the branching fraction for the decay B⁺→ψ(2S)ϕ(1020)K⁺ is found to be (3.0±0.2±0.5±0.2)×10⁻⁶.

Observation of a new charmed baryon decaying to Ξc⁺π⁻π⁺ arxiv.org/abs/2502.18987 - The Ξc(2923)⁺ baryon is observed for the first time, and is consistent with being the isospin partner of the previously observed Ξc(2923)⁰ state.

Angular analysis of B⁰→K*⁰e⁺e⁻ decays arxiv.org/abs/2502.10291 - In general, the angular observables are found to be consistent with the Standard Model expectations as well as with global analyses of other b→sℓ⁺ℓ⁻ processes.

Search for resonance-enhanced CP and angular asymmetries in the Λc⁺→ pμ⁺μ⁻ decay at LHCb arxiv.org/abs/2502.04013 - The asymmetries are consistent with the conservation of CP symmetry and the Standard Model expectations.

Evidence for B⁻→ D**⁰τ⁻ν̅ decays arxiv.org/abs/2501.14943 - The combined branching fraction BR(B⁻→ D**⁰₁,₂τ⁻ν̅)× BR(D**⁰₁,₂→ D*⁺π⁻), where D**⁰₁,₂ denotes both D₁(2420)⁰ and D₂*(2460)⁰ contributions, is measured to be 0.051±0.013± 0.006± 0.009%.

Observation of the Λb⁰→J/ψΞ⁻K⁺ and Ξb⁰ → J/ψΞ⁻π⁺ decays arxiv.org/abs/2501.12779 - Using the Λb⁰→J/ψΛ and Ξb⁻ → J/ψΞ⁻ decays as normalisation channels, the ratios of branching fractions are measured to be (1.17±0.14±0.08)×10⁻² and 11.9±1.4±0.6)×10⁻², respectively.

Search for charge-parity violation in semileptonically tagged D⁰→K⁺π⁻ decays arxiv.org/abs/2501.11635 - The flavour oscillation parameters, relating to the differences in mass and width of the mass eigenstates, are found to be y′=(5.8±1.6)×10⁻³ and (x′)²=(0.0±1.2)×10⁻⁴.

Study of light-meson resonances decaying to Ks⁰Kπ in the B→(Ks⁰Kπ)K channels arxiv.org/abs/2501.06483 - A complex mixture of 0⁻⁺,1⁺⁺ and 1⁺⁻ resonances is observed, dominated by η(1405), η(1470), η(1760), f₁(1285), f₁(1420) and h₁(1405) resonances.

Measurement of CP asymmetry in Bₛ⁰→Dₛ⁺K⁻ decays arxiv.org/abs/2412.14074 - This result is combined with the previous LHCb measurement in this channel using 3fb⁻¹ resulting in a determination of γ=(81+12−11)∘.

Measurement of CP asymmetries in Λ⁰b → ph⁻ decays arxiv.org/abs/2412.13958 - When combining the Run 2 and updated Run 1 measurements, the final results are found to be (−1.1±0.7±0.4)% and (0.2±0.8±0.4)%, constituting the most precise measurements of these asymmetries to date.

Test of lepton flavour universality with B⁺→K⁺π⁺π⁻ℓ⁺ℓ⁻decays arxiv.org/abs/2412.11645 - The ratio of branching fractions between B⁺→K⁺π⁺π⁻e⁺e⁻ and B⁺→K⁺π⁺π⁻μ⁺μ⁻ decays is found to be in agreement with the Standard Model prediction.

Search for D⁰ meson decays to π⁺π⁻e⁺e⁻ and K⁺K⁻e⁺e⁻ final states arxiv.org/abs/2412.09414 - The decay D⁰→π⁺π⁻e⁺e⁻ is observed for the first time when requiring that the two electrons are consistent with coming from the decay of a ϕ or ρ⁰/ω meson.

Observation of the open-charm tetraquark state T*cs₀(2870)⁰ in the B⁻→D⁻D⁰K⁰s decay arxiv.org/abs/2411.19781 - This result confirms the existence of the T*cs₀(2870)⁰ state in a new decay mode.

Study of Λb⁰ and Ξb⁰ decays to Λh⁺h′⁻ and evidence for CP violation in Λb⁰→ΛK⁺K⁻ decays arxiv.org/abs/2411.15441 - Evidence is found for CP violation in the Λb⁰→ΛK⁺K⁻ decay, interpreted as originating primarily from an asymmetric Λb⁰→N*⁰K⁻ decay amplitude.

First evidence for direct CP violation in beauty to charmonium decays arxiv.org/abs/2411.12178 - The CP asymmetry of the CKM-suppressed decay B⁺→J/ψπ⁺ is measured relative to the favoured decay B⁺→J/ψK⁺ as (1.29 ± 0.49 ± 0.08) × 10⁻².

Constraints on the photon polarisation in b→sγ transitions using Bₛ⁰→ϕe⁺e⁻ decays arxiv.org/abs/2411.10219 - An angular analysis is performed in the very low dielectron invariant mass-squared region between 0.0009 and 0.2615 GeV².

Measurement of ϕ(1020) meson production in fixed-target pNe collisions at √s(NN) = 68.5 GeV arxiv.org/abs/2411.09343 - The ϕ(1020) mesons are reconstructed in their K+K− decay in a data sample consisting of proton collisions on neon nuclei at rest.

Measurement of the ψ(2S) to J/ψ cross-section ratio as a function of centrality in PbPb collisions at √s(NN) = 5.02 TeV arxiv.org/abs/2411.05669 - The measured ratio shows no dependence on the collision centrality, and is compared to the predictions and to recent measurements.

Study of Dₛ₁(2460)⁺→Dₛ⁺π⁺π⁻ in B→D⁻*Dₛ⁺π⁺π⁻ decays arxiv.org/abs/2411.03399 - The data can be described either with a model including f₀(500), and large f₀(980) and f₂(1270) contributions, or with a model including f₀(500), and open-charm tetraquark states.

Measurement of the CKM angle γ in B⁺→DK*(892)⁺ decays buff.ly/4fpfwQi - A comprehensive study of this channel is presented with the D meson reconstructed in two, three and four-body final states. The combined result gives γ=(63±13)° .