LHCb Experiment
@lhcb.bsky.social
The LHCb experiment at CERN. cern.ch/lhcb-public.
Measurement of charged-hadron distributions in heavy-flavor jets in proton-proton collisions at √s=13 TeV arxiv.org/abs/2511.10216 - The observed differences between the heavy- and light-jet distributions are consistent with the heavy-quark dynamics expected to arise from the dead-cone effect [...].
November 14, 2025 at 6:42 AM
Measurement of charged-hadron distributions in heavy-flavor jets in proton-proton collisions at √s=13 TeV arxiv.org/abs/2511.10216 - The observed differences between the heavy- and light-jet distributions are consistent with the heavy-quark dynamics expected to arise from the dead-cone effect [...].
Search for K⁰→π⁺π⁻μ⁺μ⁻ decays at LHCb arxiv.org/abs/2511.02619 - Upper limits are set for the first time on the branching fractions B(K⁰s→π⁺π⁻μ⁺μ⁻)<1.4×10⁻⁹ and B(K⁰L→π⁺π⁻μ⁺μ⁻)<6.6×10⁻⁷, at the 90% confidence level.
November 5, 2025 at 8:46 AM
Search for K⁰→π⁺π⁻μ⁺μ⁻ decays at LHCb arxiv.org/abs/2511.02619 - Upper limits are set for the first time on the branching fractions B(K⁰s→π⁺π⁻μ⁺μ⁻)<1.4×10⁻⁹ and B(K⁰L→π⁺π⁻μ⁺μ⁻)<6.6×10⁻⁷, at the 90% confidence level.
For the first time LHCb recorded 10/fb pp collisions in a single year.
The legacy detector which we upgraded in 2018-21 collected a total of 9/fb between 2010 and 2018.
The legacy detector which we upgraded in 2018-21 collected a total of 9/fb between 2010 and 2018.
October 17, 2025 at 6:21 AM
For the first time LHCb recorded 10/fb pp collisions in a single year.
The legacy detector which we upgraded in 2018-21 collected a total of 9/fb between 2010 and 2018.
The legacy detector which we upgraded in 2018-21 collected a total of 9/fb between 2010 and 2018.
Measurement of CP asymmetry in D⁰→KsKs decays with the LHCb Upgrade I detector arxiv.org/abs/2510.14732 - A measurement of CP asymmetry in D⁰→KsKs decays is reported using 6.2/fb recorded with the LHCb Upgrade I detector. This is the most precise determination of this quantity to date.
October 17, 2025 at 6:07 AM
Measurement of CP asymmetry in D⁰→KsKs decays with the LHCb Upgrade I detector arxiv.org/abs/2510.14732 - A measurement of CP asymmetry in D⁰→KsKs decays is reported using 6.2/fb recorded with the LHCb Upgrade I detector. This is the most precise determination of this quantity to date.
Searches for B⁰→K⁺π⁻τ⁺τ⁻ and Bₛ⁰→K⁺K⁻τ⁺τ⁻ decays arxiv.org/abs/2510.13716 - This is he first limit for the Bₛ⁰→K⁺K⁻τ⁺τ⁻ decay. For the decay B⁰→K*(892)⁰τ⁺τ⁻, this result improves on the current best upper limit by an order of magnitude.
October 16, 2025 at 8:54 AM
Searches for B⁰→K⁺π⁻τ⁺τ⁻ and Bₛ⁰→K⁺K⁻τ⁺τ⁻ decays arxiv.org/abs/2510.13716 - This is he first limit for the Bₛ⁰→K⁺K⁻τ⁺τ⁻ decay. For the decay B⁰→K*(892)⁰τ⁺τ⁻, this result improves on the current best upper limit by an order of magnitude.
Study of charm mixing and CP violation with D⁰→K⁺π⁻π⁺π⁻ decays arxiv.org/abs/2510.04963 - It is found that x=(0.85+0.15−0.24)%, y=(0.21+0.29−0.27)%, Δx=(−0.02±0.04)% and Δy=(0.02+0.04−0.03)%. These results are consistent with previous measurements and the hypothesis of CP conservation.
October 7, 2025 at 5:57 AM
Study of charm mixing and CP violation with D⁰→K⁺π⁻π⁺π⁻ decays arxiv.org/abs/2510.04963 - It is found that x=(0.85+0.15−0.24)%, y=(0.21+0.29−0.27)%, Δx=(−0.02±0.04)% and Δy=(0.02+0.04−0.03)%. These results are consistent with previous measurements and the hypothesis of CP conservation.
Measurement of the W→μν cross-sections as a function of the muon transverse momentum in pp collisions at 5.02 TeV arxiv.org/abs/2509.18817 - This analysis introduces a new method to determine the W-boson mass using the measured differential cross-sections corrected for detector effects.
September 24, 2025 at 6:26 AM
Measurement of the W→μν cross-sections as a function of the muon transverse momentum in pp collisions at 5.02 TeV arxiv.org/abs/2509.18817 - This analysis introduces a new method to determine the W-boson mass using the measured differential cross-sections corrected for detector effects.
Observation of Bc⁺→D⁺h⁺h⁻decays arxiv.org/abs/2509.15873 - The decays Bc⁺→D⁺K⁺π⁻, Bc⁺→D*⁺K⁺π⁻ and Bc⁺→Dₛ⁺K⁺K⁻ are observed for the first time.
September 22, 2025 at 6:17 AM
Observation of Bc⁺→D⁺h⁺h⁻decays arxiv.org/abs/2509.15873 - The decays Bc⁺→D⁺K⁺π⁻, Bc⁺→D*⁺K⁺π⁻ and Bc⁺→Dₛ⁺K⁺K⁻ are observed for the first time.
First evidence of CP violation in beauty baryon to charmonium decays arxiv.org/abs/2509.16103 - The difference in the CP asymmetries between Λ⁰b→J/ψpπ⁻ and Λ⁰b→J/ψKπ⁻ decays is measured to be ΔACP=(4.0±1.2±0.2)%.
September 22, 2025 at 6:12 AM
First evidence of CP violation in beauty baryon to charmonium decays arxiv.org/abs/2509.16103 - The difference in the CP asymmetries between Λ⁰b→J/ψpπ⁻ and Λ⁰b→J/ψKπ⁻ decays is measured to be ΔACP=(4.0±1.2±0.2)%.
A model-independent measurement of the CKM angle γ in the decays B⁺→[K⁺K⁻π⁺π⁻]h⁺ and B⁺→[π⁺π⁻π⁺π⁻]h⁺ (h=K,π) arxiv.org/abs/2509.15139 - The result of this binned analysis is γ=(53.9+9.5−8.9)∘, where the uncertainty includes both statistical and systematic contributions.
September 19, 2025 at 6:17 AM
A model-independent measurement of the CKM angle γ in the decays B⁺→[K⁺K⁻π⁺π⁻]h⁺ and B⁺→[π⁺π⁻π⁺π⁻]h⁺ (h=K,π) arxiv.org/abs/2509.15139 - The result of this binned analysis is γ=(53.9+9.5−8.9)∘, where the uncertainty includes both statistical and systematic contributions.
Measurement of the branching fraction of the Λb⁰→J/ψΛ decay and isospin asymmetry of B→J/ψK decays arxiv.org/abs/2509.12805 - B(Λb⁰→J/ψΛ)=(3.34±0.02±0.10±0.08±0.28)×10−4. In addition, the isospin asymmetry between the rates of B⁰→J/ψK⁰s and B⁺→J/ψK+ decays is measured to be AI=−0.0135±0.0004±0.0133.
September 17, 2025 at 5:51 AM
Measurement of the branching fraction of the Λb⁰→J/ψΛ decay and isospin asymmetry of B→J/ψK decays arxiv.org/abs/2509.12805 - B(Λb⁰→J/ψΛ)=(3.34±0.02±0.10±0.08±0.28)×10−4. In addition, the isospin asymmetry between the rates of B⁰→J/ψK⁰s and B⁺→J/ψK+ decays is measured to be AI=−0.0135±0.0004±0.0133.
Amplitude analysis of B⁰→ηc(1S)K⁺π⁻ decays arxiv.org/abs/2509.03133 - The data are described with a model including only intermediate contributions from known K*⁰ resonances. Evidence for an exotic resonance in the ηcπ⁻ system, reported in a previous analysis of this decay channel, is not confirmed.
September 4, 2025 at 5:43 AM
Amplitude analysis of B⁰→ηc(1S)K⁺π⁻ decays arxiv.org/abs/2509.03133 - The data are described with a model including only intermediate contributions from known K*⁰ resonances. Evidence for an exotic resonance in the ηcπ⁻ system, reported in a previous analysis of this decay channel, is not confirmed.
Inclusive B-meson flavour-tagging algorithm at LHCb arxiv.org/abs/2508.20180 - This new algorithm improves the tagging power by 35% for B0 mesons and 20% for B0s mesons when compared to the combined performance of the existing LHCb flavour-tagging algorithms.
August 29, 2025 at 4:57 AM
Inclusive B-meson flavour-tagging algorithm at LHCb arxiv.org/abs/2508.20180 - This new algorithm improves the tagging power by 35% for B0 mesons and 20% for B0s mesons when compared to the combined performance of the existing LHCb flavour-tagging algorithms.
Measurement of branching fractions and CP asymmetries in Λb⁰(Ξb⁰)→pKs⁰h⁻ decays arxiv.org/abs/2508.17836 - The decays Λb⁰ and Ξb⁰→pKs⁰K⁻ are observed for the first time. No evidence of CP violation is observed.
August 26, 2025 at 5:43 AM
Measurement of branching fractions and CP asymmetries in Λb⁰(Ξb⁰)→pKs⁰h⁻ decays arxiv.org/abs/2508.17836 - The decays Λb⁰ and Ξb⁰→pKs⁰K⁻ are observed for the first time. No evidence of CP violation is observed.
First observation of the charmless baryonic decay B⁺→Λ̅pp̅p arxiv.org/abs/2508.16259 - The branching fraction for this decay is measured for the first time, as (2.08±0.34±0.12±0.26)×10⁻⁷. The mass distributions of Λ̅p and p̅p pairs exhibit pronounced enhancements at both kinematic thresholds.
August 25, 2025 at 5:48 AM
First observation of the charmless baryonic decay B⁺→Λ̅pp̅p arxiv.org/abs/2508.16259 - The branching fraction for this decay is measured for the first time, as (2.08±0.34±0.12±0.26)×10⁻⁷. The mass distributions of Λ̅p and p̅p pairs exhibit pronounced enhancements at both kinematic thresholds.
First observation of CP violation and measurement of polarization in B⁺→ρ(770)⁰K*(892)⁺ decays arxiv.org/abs/2508.13563 - The CP asymmetry is measured to be 0.507±0.062)±0.017 and the CP-averaged longitudinal polarization fraction 0.720±0.028±0.009.
August 20, 2025 at 6:03 AM
First observation of CP violation and measurement of polarization in B⁺→ρ(770)⁰K*(892)⁺ decays arxiv.org/abs/2508.13563 - The CP asymmetry is measured to be 0.507±0.062)±0.017 and the CP-averaged longitudinal polarization fraction 0.720±0.028±0.009.
Deuteron identification via time of flight with LHCb arxiv.org/abs/2508.06305 - The timing capabilities of the LHCb detector operated during the LHC Run 2 can be used to identify light ion particles with momenta of a few GeV/c.
August 11, 2025 at 7:14 AM
Deuteron identification via time of flight with LHCb arxiv.org/abs/2508.06305 - The timing capabilities of the LHCb detector operated during the LHC Run 2 can be used to identify light ion particles with momenta of a few GeV/c.
Search for the decay B⁰→ϕϕ arxiv.org/abs/2507.20945 - No significant signal is observed, and an upper limit on the branching fraction of 1.3 (1.4)×10⁻⁸ at 90 (95)% confidence level is set.
July 29, 2025 at 7:16 AM
Search for the decay B⁰→ϕϕ arxiv.org/abs/2507.20945 - No significant signal is observed, and an upper limit on the branching fraction of 1.3 (1.4)×10⁻⁸ at 90 (95)% confidence level is set.
Search for resonances decaying to photon pairs with masses between 4.9 and 19.4 GeV arxiv.org/abs/2507.14390 - Upper limits on the photon-pair branching fraction times the cross-section of ALP production are determined, as well as B(Bs⁰→γγ)<2.7×10⁻⁵, B(B⁰→γγ)<0.83×10⁻⁵ and σ(pp→ηbX)×B(ηb→γγ)<765pb.
July 22, 2025 at 6:27 AM
Search for resonances decaying to photon pairs with masses between 4.9 and 19.4 GeV arxiv.org/abs/2507.14390 - Upper limits on the photon-pair branching fraction times the cross-section of ALP production are determined, as well as B(Bs⁰→γγ)<2.7×10⁻⁵, B(B⁰→γγ)<0.83×10⁻⁵ and σ(pp→ηbX)×B(ηb→γγ)<765pb.
Measurement of the B⁰→ρ(770)⁰γ branching fraction arxiv.org/abs/2507.14401 - The branching fraction for is obtained as (7.9±0.3±0.2±0.2)×10⁻⁷. It is consistent with the current world-average value and by far the most precise measurement to date.
July 22, 2025 at 6:23 AM
Measurement of the B⁰→ρ(770)⁰γ branching fraction arxiv.org/abs/2507.14401 - The branching fraction for is obtained as (7.9±0.3±0.2±0.2)×10⁻⁷. It is consistent with the current world-average value and by far the most precise measurement to date.
Improved measurement of η/η′ mixing in B⁰ and Bs⁰→J/ψη⁽'⁾decays arxiv.org/abs/2507.13914 - The angle ϕG differs from zero by more than four standard deviations, which points to a substantial glueball component and/or unexpectedly large contributions from gluon-mediated processes in these decays.
July 21, 2025 at 6:40 AM
Improved measurement of η/η′ mixing in B⁰ and Bs⁰→J/ψη⁽'⁾decays arxiv.org/abs/2507.13914 - The angle ϕG differs from zero by more than four standard deviations, which points to a substantial glueball component and/or unexpectedly large contributions from gluon-mediated processes in these decays.
Study of Bc(1P)⁺ states in the Bc⁺γ mass spectrum arxiv.org/abs/2507.02142 - Based on the predictions for the Bc(1P)⁺ spectrum, the relative production cross-section of the overall Bc(1P)⁺ states with respect to the Bc⁺ ground state is measured to be 0.20±0.03±0.02±0.03.
July 4, 2025 at 9:05 AM
Study of Bc(1P)⁺ states in the Bc⁺γ mass spectrum arxiv.org/abs/2507.02142 - Based on the predictions for the Bc(1P)⁺ spectrum, the relative production cross-section of the overall Bc(1P)⁺ states with respect to the Bc⁺ ground state is measured to be 0.20±0.03±0.02±0.03.
Observation of orbitally excited Bc⁺ states arxiv.org/abs/2507.02149 - The observation of a wide peaking structure in the B+cγ mass spectrum is reported and well described by an effective minimal model consisting of two narrow peaks located at 6704.8±5.5±2.8±0.3 MeV and 6752.4±9.5±3.1±0.3 MeV.
July 4, 2025 at 9:05 AM
Observation of orbitally excited Bc⁺ states arxiv.org/abs/2507.02149 - The observation of a wide peaking structure in the B+cγ mass spectrum is reported and well described by an effective minimal model consisting of two narrow peaks located at 6704.8±5.5±2.8±0.3 MeV and 6752.4±9.5±3.1±0.3 MeV.
Updated measurement of CP violation and polarisation in B⁰s→J/ψK̅*(892)⁰ decays arxiv.org/abs/2506.22090 - The longitudinal and parallel polarisation fractions are determined to be f₀=0.534±0.012±0.009 and f∥=0.211±0.014±0.005, providing the most precise values for these observables to date.
June 30, 2025 at 6:00 AM
Updated measurement of CP violation and polarisation in B⁰s→J/ψK̅*(892)⁰ decays arxiv.org/abs/2506.22090 - The longitudinal and parallel polarisation fractions are determined to be f₀=0.534±0.012±0.009 and f∥=0.211±0.014±0.005, providing the most precise values for these observables to date.
Search for the lepton-flavour-violating decays B⁰→K*⁰τ⁺e⁻ arxiv.org/abs/2506.15347 - No significant signal is observed, and upper limits on the branching fractions are determined to be B(B⁰→K*⁰τ⁻e⁺)<5.9 (7.1)×10⁻⁶ and B(B⁰→K*⁰τ⁺e⁻)<4.9 (5.9)×10⁻⁶ at the 90% (95%) confidence level.
June 19, 2025 at 7:15 AM
Search for the lepton-flavour-violating decays B⁰→K*⁰τ⁺e⁻ arxiv.org/abs/2506.15347 - No significant signal is observed, and upper limits on the branching fractions are determined to be B(B⁰→K*⁰τ⁻e⁺)<5.9 (7.1)×10⁻⁶ and B(B⁰→K*⁰τ⁺e⁻)<4.9 (5.9)×10⁻⁶ at the 90% (95%) confidence level.