LHCb Physics

The forward experiment at the LHC. We tweet @lhcbexperiment physics results. Managed by @PKoppenburg and @muheim. Also at 🐘.

[LHCb Physics @LHCbPhysics]

Branching fraction measurement of the decay B⁺→ψ(2S)ϕ(1020)K⁺ https://t.co/F4NQmTwYVv - 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.

[LHCb Physics @LHCbPhysics]

Observation of a new charmed baryon decaying to Ξc⁺π⁻π⁺ https://t.co/RBVIRlGkSp - 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.

[LHCb Physics @LHCbPhysics]

Angular analysis of B⁰→K*⁰e⁺e⁻ decays https://t.co/9YMhiHRYLS - 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.

[LHCb Physics @LHCbPhysics]

Search for resonance-enhanced CP and angular asymmetries in the Λc⁺→ pμ⁺μ⁻ decay at LHCb https://t.co/pbBwc31EpG - The asymmetries are consistent with the conservation of CP symmetry and the Standard Model expectations.

[LHCb Physics @LHCbPhysics]

Evidence for B⁻→ D**⁰τ⁻ν̅ decays https://t.co/uSNSo4C0Uc - 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%.

[LHCb Physics @LHCbPhysics]

Observation of the Λb⁰→J/ψΞ⁻K⁺ and Ξb⁰ → J/ψΞ⁻π⁺ decays https://t.co/YFO7z0TR8j - 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.

[LHCb Physics @LHCbPhysics]

Search for charge-parity violation in semileptonically tagged D⁰→K⁺π⁻ decays https://t.co/sYLOZECSQ5 - 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.

[LHCb Physics @LHCbPhysics]

Study of light-meson resonances decaying to Ks⁰Kπ in the B→(Ks⁰Kπ)K channels https://t.co/17bZuNiWsJ - 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.

[LHCb Physics @LHCbPhysics]

Measurement of CP asymmetry in Bₛ⁰→Dₛ⁺K⁻ decays https://t.co/vrtkozFAt9 - This result is combined with the previous LHCb measurement in this channel using 3fb⁻¹ resulting in a determination of γ=(81+12−11)∘.

[LHCb Physics @LHCbPhysics]

Measurement of CP asymmetries in Λ⁰b → ph⁻ decays https://t.co/BmyRkC2d8G - 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.

[LHCb Physics @LHCbPhysics]

Test of lepton flavour universality with B⁺→K⁺π⁺π⁻ℓ⁺ℓ⁻decays https://t.co/gBucwwcW6B - 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.

[LHCb Physics @LHCbPhysics]

Search for D⁰ meson decays to π⁺π⁻e⁺e⁻ and K⁺K⁻e⁺e⁻ final states https://t.co/QtuJvat0FH - 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.

[LHCb Physics @LHCbPhysics]

Observation of the open-charm tetraquark state T*cs₀(2870)⁰ in the B⁻→D⁻D⁰K⁰s decay https://t.co/3DrTC3ulpG - This result confirms the existence of the T*cs₀(2870)⁰ state in a new decay mode.

[LHCb Physics @LHCbPhysics]

Study of Λb⁰ and Ξb⁰ decays to Λh⁺h′⁻ and evidence for CP violation in Λb⁰→ΛK⁺K⁻ decays https://t.co/W771d8cA6l - Evidence is found for CP violation in the Λb⁰→ΛK⁺K⁻ decay, interpreted as originating primarily from an asymmetric Λb⁰→N*⁰K⁻ decay amplitude.

[LHCb Physics @LHCbPhysics]

First evidence for direct CP violation in beauty to charmonium decays https://t.co/9Ve1wM2386 - 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.

[LHCb Physics @LHCbPhysics]

Constraints on the photon polarisation in b→sγ transitions using Bₛ⁰→ϕe⁺e⁻ decays https://t.co/qCbWtJL1nN - An angular analysis is performed in the very low dielectron invariant mass-squared region between 0.0009 and 0.2615 GeV².

[LHCb Physics @LHCbPhysics]

Measurement of ϕ(1020) meson production in fixed-target pNe collisions at √s(NN) = 68.5 GeV https://t.co/mfWfuWyxy9 - The ϕ(1020) mesons are reconstructed in their K+K− decay in a data sample consisting of proton collisions on neon nuclei at rest.

[LHCb Physics @LHCbPhysics]

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 https://t.co/mUHctusejg - The measured ratio shows no dependence on the collision centrality, and is compared to the predictions and to recent measurements.

[LHCb Physics @LHCbPhysics]

Study of Dₛ₁(2460)⁺→Dₛ⁺π⁺π⁻ in B→D⁻*Dₛ⁺π⁺π⁻ decays https://t.co/HNTkBp3qA5 - 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.

[LHCb Physics @LHCbPhysics]

Measurement of the CKM angle γ in B⁺→DK*(892)⁺ decays https://t.co/7sWAFBnxv2 - 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)° .