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LHCb Experiment

@lhcb.bsky.social
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The LHCb experiment at CERN. cern.ch/lhcb-public.

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LHCb Experiment @lhcb.bsky.social · 24/09/2026
Discovery of an unexpectedly light and narrow beauty-strange state - It exhibits a narrow natural width and a substantial mass deficit compared to the conventional quark model predictions. This result marks the first observation of a nonconventional single-beauty hadron. arxiv.org/abs/2609.25178
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LHCb Experiment @lhcb.bsky.social · 23/09/2026
Measurement of the Ωb⁻ baryon lifetime - The Ωb⁻ lifetime is 1.751±0.089±0.022 ps, where the uncertainties are statistical and systematic. This measurement improves on the precision of the Ωb⁻ lifetime by about a factor of two over the previous world average. arxiv.org/abs/2609.25370
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LHCb Experiment @lhcb.bsky.social · 22/09/2026
First measurement of the forward rapidity dependence of W boson transverse helicity fractions - The results show a strong rapidity dependence and agree with NLO SM predictions, providing the first determination of the W transverse helicity fractions in the forward region. arxiv.org/abs/2609.22555
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LHCb Experiment @lhcb.bsky.social · 21/09/2026
Observation of the doubly charmed baryon Ωcc⁺ - A peaking structure with a global significance of 8.7σ is observed in the Ωc⁰π⁺mass spectrum at a mass of 3725.9±1.0±0.2±0.4(lifetime)±0.6(ext) MeV arxiv.org/abs/2609.21921
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LHCb Experiment @lhcb.bsky.social · 15/09/2026
Observation of Ξb⁰→Ξ⁰J/ψ and evidence for Ξb⁰→Ξ⁰ψ(2S) decays - The Ξ⁰ hyperon is fully reconstructed for the first time at an LHC experiment, which is achieved using the Ξ⁰→Λπ⁰ decay. arxiv.org/abs/2609.15251
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LHCb Experiment @lhcb.bsky.social · 04/09/2026
Branching fraction measurements of η and η′(958) anomalous decays - This marks the first experimental search for the η′(958)→μ⁺μ⁻ decay, and the most precise measurement of the branching fraction B(η→μ⁺μ⁻) to date. arxiv.org/abs/2609.02973
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LHCb Experiment @lhcb.bsky.social · 03/09/2026
Stringent limits on CPT- and Lorentz-invariance violation from Bₛ⁰ meson decays - Without assuming Lorentz-invariance violation, the CPT-violating parameter zis measured to be Re(z)=0.018±0.016±0.003 and Im(z)=0.003±0.004±0.002. arxiv.org/abs/2609.02475
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LHCb Experiment @lhcb.bsky.social · 01/09/2026
First measurement of the ratio of ψ(2S)-to-J/ψ inclusive production in pAr and pp collisions at √s=113GeV with SMOG2 - Data samples were collected during argon and hydrogen gas injections in the SMOG2 storage cell, resulting in pAr and pp collisions, respectively. arxiv.org/abs/2608.30534
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LHCb Experiment @lhcb.bsky.social · 31/08/2026
Observation of the Ξc⁰→ pK⁻ decay and measurement of its decay asymmetry - Using the decay chain Ξb⁻→Ξc⁰(→ pK⁻)π⁻, the decay asymmetry parameter of the Ξc⁰→ pK⁻ decay is determined to be 0.32±0.15±0.01. arxiv.org/abs/2608.27894
Mass plots
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LHCb Experiment @lhcb.bsky.social · 24/08/2026
Angular analysis of the decay Λb⁰→Λ(1520)μ⁺μ⁻ - The leptonic forward-backward asymmetry and the angular observable S1cc are determined by fitting projections of the angular distributions in four intervals of the square of the dimuon invariant mass. arxiv.org/abs/2608.21082
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LHCb Experiment @lhcb.bsky.social · 19/08/2026
Search for B meson decays to multimuon final states - No signal is found, and upper limits spanning the range of 0.6×10⁻⁹ to 5.4×10⁻⁷ are set on their branching fractions. In addition, limits across the intermediate-particle lifetime ranges considered are determined. arxiv.org/abs/2608.17855
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LHCb Experiment @lhcb.bsky.social · 17/08/2026
Amplitude analysis of B⁺→K⁺π⁺π⁻ decays - The most challenging aspect lies in the description of the S-wave contributions. This is achieved by three complementary approaches based on the isobar approximation, the K-matrix formalism, and a quasi-model-independent procedure. arxiv.org/abs/2608.12612
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LHCb Experiment @lhcb.bsky.social · 17/08/2026
Improved measurement of CP violation in Bₛ⁰→J/ψπ⁺π⁻ decays - The combination with previous measurements yields ϕs=−0.046±0.031rad, |λ|=0.975±0.024 and ΓH=0.610±0.004ps−1, while the combination including all other LHCb measurements gives ϕs=−0.041±0.017rad. arxiv.org/abs/2608.14119
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LHCb Experiment @lhcb.bsky.social · 13/08/2026
Model-independent measurement of the transversity amplitudes of the B⁰→K*⁰μ⁺μ⁻ decay - Depending on the binning scheme, the deviation of the Wilson coefficient C9 from its Standard Model expectation varies from 4.3σ to 4.8σ. arxiv.org/abs/2608.12215
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LHCb Experiment @lhcb.bsky.social · 12/08/2026
Study of muon-tagged Dₛ₁(2460)⁺ and Dₛ₁(2536)⁺ decays to the Dₛ⁺π⁺π⁻ final state - The Dalitz-plot distributions of the two decays are found to be different, suggesting differences in the internal structure of the two states, with evidence of exotic contributions. arxiv.org/pdf/2608.10826
Dalitz plot of the Ds(2460)Dalitz plot of the Ds(2536)
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LHCb Experiment @lhcb.bsky.social · 05/08/2026
New measurements of Bc decays into single charm final states - Five products of branching fraction, B(Bc→DX), and fragmentation ratio fc/fu are reported, Additionally, the CP asymmetry in Bc→D0K decays is measured and found to be compatible with zero. arxiv.org/abs/2608.03453
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Reposted by LHCb Experiment
Patrick Koppenburg 🐧 @koppenburg.ch · 29/07/2026
Final readings of @lhcb.bsky.social papers: we have 7 papers these two weeks. And that's not yet counting the new results that will be shown at ICHEP. #LHCbEditorialBoard
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LHCb Experiment @lhcb.bsky.social · 04/08/2026
Modification of Υ production in pO and OO collisions at LHCb - The significant suppression in OO data, compared to the small effect in pO data, shows the emergence of additional suppression mechanisms in the relatively small OO collision system. arxiv.org/abs/2608.00182
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LHCb Results @lhcbpapers.bsky.social · 23/07/2026
#LHCbpaper soon on arXiv: Search for CP violation in D⁺ → ϕπ⁺ decays (CERN-EP-2026-158) cds.cern.ch/record/2967099
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LHCb Experiment @lhcb.bsky.social · 15/07/2026
Search for the decays B(c)⁺→μ⁺νγ - No evidence for an excess of events over background is observed for either signal decay. This constitutes the first search for these decays at a hadron collider and the first experimental investigation of the Bc⁺→μ⁺νγ decay to date. arxiv.org/abs/2607.12825
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LHCb Experiment @lhcb.bsky.social · 14/07/2026
Observation of new excited Σc⁰ states in the B⁻→Λc⁺p̅π⁻ decay - the known Σc(2455)⁰, Σc(2520)⁰, Σc(2800)⁰ baryons are observed, along with two new states: Σc(2900)⁰ and Σc(3200)⁰. arxiv.org/abs/2607.10595
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National Institute for Subatomic Physics (Nikhef) @nikhef.bsky.social · 09/07/2026
Used VELO subdetector on display at Nikhef, after a proven track record at CERN www.nikhef.nl/en/news/used... @cern.bsky.social @lhcb.bsky.social
nikhef.nl
Used VELO subdetector on display at Nikhef, after a proven track record at CERN - Nikhef
The VELO subdetector, which for many years was one of the central components of the LHCb experiment at CERN, is back at Nikhef. This showcase of Nikhef technology...
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LHCb Experiment @lhcb.bsky.social · 23/06/2026
Differential measurement of the branching fraction and CP asymmetry of the decay B⁺→π⁺μ⁺μ⁻ - The measured branching fractions are compatible with the predictions of the Standard Model, with consistency varying between 1.4σ and 3.8σ depending on the model assumptions. arxiv.org/abs/2606.23646
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CERN @cern.bsky.social · 18/06/2026
The @lhcb.bsky.social discovers the final missing member of a doubly charmed particle family 💫 The new particle, composed of one strange quark and two charm quarks, completes a set of particles first theorised over half a century ago. Find out more: home.cern/lhcb-discove...
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LHCb Experiment @lhcb.bsky.social · 10/06/2026
Measurement of the ratio of branching fractions B(Bc⁺→J/ψτ⁺ν)/B(Bc⁺→J/ψμ⁺ν) - The measured value is found to be R(J/ψ)=0.51±0.12(stat)±0.08(syst), which is within 1.8 standard deviations of the predictions from the Standard Model assuming lepton flavor universality. arxiv.org/pdf/2606.10018
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LHCb Experiment @lhcb.bsky.social · 05/06/2026
Associated Z + J/ψ production as a probe of multiparton interactions in the forward region - The measured cross-section is 5.5±1.5 pb, significantly exceeding the single-parton scattering expectation of 0.10±0.08 pb, indicating that multiparton interactions dominate. arxiv.org/abs/2606.05786
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LHCb Experiment @lhcb.bsky.social · 03/06/2026
Observation of the doubly charmed baryon Ωcc+ lhcb-outreach.web.cern.ch/2026/06/03/o...
lhcb-outreach.web.cern.ch
Observation of the doubly charmed baryon Ωcc+
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LHCb Experiment @lhcb.bsky.social · 27/05/2026
Study of nuclear effects on charm production in light-ion collisions - The onset of nuclear effects in light-ion collisions is studied by measuring the ratio of D meson production between NeNe and OO collisions at a center-of-mass energy per nucleon pair of 5.36TeV. arxiv.org/abs/2605.27273
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LHCb Experiment @lhcb.bsky.social · 11/05/2026
Evidence for the decay Bₛ⁰→ϕη' - The branching ratio relative to the Bₛ⁰→ϕϕ decay is determined to be R=(3.56±0.79±0.18±0.06)×10⁻² arxiv.org/abs/2605.07586
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LHCb Experiment @lhcb.bsky.social · 11/05/2026
CP violation analysis of local and nonlocal amplitudes in the B⁰→K*⁰μ⁺μ⁻ decay - The precision of the CP-violation observables is improved by an order of magnitude relative to previous measurement. No significant CP violation is observed. arxiv.org/abs/2605.07582
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LHCb Experiment @lhcb.bsky.social · 07/05/2026
Observation of the chΛb⁰→Λpp̅ - The signal decay is observed with a significance of 5.1 standard deviations. arxiv.org/abs/2605.04348
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LHCb Experiment @lhcb.bsky.social · 06/05/2026
Measurement of γ using B⁺→ DK⁺ and B⁺→ Dπ⁺ decays with D→Ks⁰π⁺π⁻ and D→Ks⁰K⁺K⁻ - A measurement of the CKM angle γ is performed with a data sample collected during 2024 by the upgraded LHCb experiment. The CKM angle γ is determined to be γ=(68.1±6.7)∘. arxiv.org/abs/2605.03501
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LHCb Experiment @lhcb.bsky.social · 30/04/2026
First evidence of the decay B⁺→K⁺e⁺e⁻ - A signal excess with a significance of 3.2σ is observed and the branching fraction is measured to be BR(B⁺→K⁺e⁺e⁻)=(2.4+0.9−0.8+0.4−0.2)×10⁻⁸, where the first set of uncertainties is statistical and the second is systematic arxiv.org/abs/2604.26784
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LHCb Experiment @lhcb.bsky.social · 27/04/2026
Angular analysis of the B⁺→π⁺μ⁺μ⁻ decay - The Standard Model predictions lie within the obtained 68% confidence level interval in the high-mass and within the 99% interval in the low-mass region. arxiv.org/abs/2604.21987
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LHCb Experiment @lhcb.bsky.social · 24/04/2026
Observation of a new excited charm-strange meson Dₛ₁(2933)⁺ in B⁰→D⁺D⁻K⁺π⁻ decays - Its Breit-Wigner mass and width are measured to be 2933 MeV and 72 MeV, respectively, and its spin-parity 1⁺. This new meson is a candidate for a Dₛ(2P₁)⁺ state. arxiv.org/abs/2604.21257
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LHCb Experiment @lhcb.bsky.social · 20/04/2026
Study of the B⁰→Λc⁺Λ̅c⁻Ks⁰ decay - Evidence is found for contributions from two resonant states, Ξc(2923)⁺ and Ξc(2939)⁺, in the Λc⁺Ks⁰ system. arxiv.org/abs/2604.15040
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LHCb Experiment @lhcb.bsky.social · 15/04/2026
Precision measurement of the muon charge asymmetry from W-boson decays in pp collisions at √s = 13 TeV in the forward region - This result represents the most precise determination of the muon charge asymmetry in the forward region to date. arxiv.org/abs/2604.12593
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LHCb Experiment @lhcb.bsky.social · 15/04/2026
Measurement of inclusive production of charmonium states in b-hadron decays via their decay into ϕϕ - The inclusive production of the ηc(1S), ηc(2S) and χc charmonium states in b-hadron decays is studied with LHCb Run~2 data using charmonia decays to ϕϕ pairs. arxiv.org/abs/2604.11123
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LHCb Experiment @lhcb.bsky.social · 13/04/2026
Test of lepton flavour universality with B⁰→ K*⁰ℓ⁺ℓ⁻ decays at large dilepton invariant mass - The ratio of branching fractions between the muon and electron channels is measured to be 1.08+0.14−0.12(stat) ±0.07(syst) for a dilepton-invariant-mass squared above 14.0 GeV² arxiv.org/abs/2604.08631
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LHCb Experiment @lhcb.bsky.social · 11/04/2026
Precise measurement of the CKM angle γ with a novel approach - A measurement of the CKM angle γ is performed by applying a novel, unbinned, model-independent approach to datasets of collected by the BESIII and LHCb experiments and yields γ=(71.3±5.0)∘. arxiv.org/abs/2604.05701
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LHCb Experiment @lhcb.bsky.social · 11/04/2026
Search for the lepton-flavour violating decays B⁺→π⁺μ⁺e⁻ and B⁺→π⁺μ⁻e⁺ - No signal is observed and an upper limit on the branching fraction is set at <1.8×10⁻⁹ at the 90% confidence level, two orders of magnitude more restrictive than the current world average. arxiv.org/abs/2604.08396
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LHCb Experiment @lhcb.bsky.social · 06/04/2026
Search for the decays Bₛ⁰→J/ψγ at LHCb - Assuming no contribution from B⁰→J/ψγ decay, an upper limit is set on the branching fraction B(Bₛ⁰→J/ψγ)<2.9× 10⁻⁶. If no contribution from Bₛ⁰→J/ψγ decay is assumed, the limit is B(B⁰→J/ψγ)<2.5×10⁻⁶ at the 90% confidence level. arxiv.org/pdf/2604.02933
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LHCb Experiment @lhcb.bsky.social · 31/03/2026
Observation of the doubly charmed baryon Ξcc⁺ with the LHCb Run 3 detector - The Ξ+cc mass is measured to be 3619.97±0.83±0.26+1.90−1.30MeV, where the third uncertainty is due to the unknown lifetime, which is assumed to lie in the range 15-160 fs. arxiv.org/abs/2603.28456
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LHCb Experiment @lhcb.bsky.social · 31/03/2026
Measurement of CP asymmetries in B̅⁰→Dₛ⁻D⁺ and B̅⁰ₛ→Dₛ⁺D⁻ decays - The measurements are found to be ACP(B̅⁰→Dₛ⁻D⁺) = 0.0009±0.0053±0.0040, ACP(B̅⁰ₛ→Dₛ⁺D⁻ ) = 0.103±0.053±0.010, This is the first measurement of this asymmetry in B̅⁰ₛ decays. arxiv.org/abs/2603.28132
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LHCb Experiment @lhcb.bsky.social · 26/03/2026
B-jet fragmentation with B⁺→ J/ψK⁺ decays in √s=13 TeV pp collisions at LHCb arxiv.org/abs/2603.23663 - The results suggest a growing contribution of gluon fragmentation to B⁺ mesons as the jet transverse momentum increases.
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Reposted by LHCb Experiment
CERN @cern.bsky.social · 17/03/2026
The LHCb Collaboration discovers new proton-like particle Composed of two charm quarks and one down quark, the doubly charmed particle is four times heavier than a proton. Find out more: home.cern/news/news/ex...
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LHCb Experiment @lhcb.bsky.social · 16/03/2026
Measurement of the local and nonlocal amplitudes in B⁺→ K⁺μ⁺μ⁻ decays arxiv.org/abs/2603.12477 - The compatibility of the Wilson coefficient combinations C9+C′9 and C10+C′10 with the Standard Model prediction is found to vary between 1.6σ and 4σ, depending on the choice of local form factors.
Fit to the m(µµ) distribution using form factors from the HPQCD collaboration for: (top left) negative J/ψ phase, positive ψ(2S) phase; (top right) positive J/ψ phase, positive ψ(2S) phase; (bottom left) negative J/ψ phase, negative ψ(2S) phase; (bottom right) positive J/ψ phase, negative ψ(2S) phase.
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LHCb Experiment @lhcb.bsky.social · 16/03/2026
First measurement of time-dependent CP violation in the decay flavor-changing neutral-current decay B⁰→Kₛ⁰μ⁺μ⁻ arxiv.org/abs/2603.13223 - The CP violation parameters are determined to be C=−0.13±0.32±0.04 and S=+0.82±0.29±0.05, are consistent with the Standard Model prediction.
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LHCb Experiment @lhcb.bsky.social · 12/03/2026
First measurement of the decay-time-integrated CP asymmetry in Bₛ⁰→Dₛ⁻π⁺ decays arxiv.org/abs/2603.10860 - The combined result, (−1.4±5.9(stat)±1.1(syst))×10⁻³, is consistent with the Standard Model expectation and provides a direct constraint on new physics in tree-level b-hadron decays.
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LHCb Experiment @lhcb.bsky.social · 10/03/2026
Improved branching-fraction measurements of B⁰(s)→ Ks⁰h⁺h⁻' decays and first observation of B⁰(s)→ Ks⁰K⁺K⁻ arxiv.org/abs/2603.08621
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