LHCb reports the first experimental evidence for the Bs0 to K- pi+ gamma decay with 3.5 sigma significance and measures its branching fraction ratio to the B0 decay in two mass ranges.
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Aaijet al.,Selection and processing of calibration samples to measure the particle identification performance of the LHCb experiment in Run 2, Eur
Tool reference. 100% of classified Pith citations use this work as a method, library, or software dependency, not as a substantive claim.
abstract
Since 2015, with the restart of the LHC for its second run of data taking, the LHCb experiment has been empowered with a dedicated computing model to select and analyse calibration samples to measure the performance of the particle identification (PID) detectors and algorithms. The novel technique was developed within the framework of the innovative trigger model of the LHCb experiment, which relies on online event reconstruction for most of the datasets, reserving offline reconstruction to special physics cases. The strategy to select and process the calibration samples, which includes a dedicated data-processing scheme combining online and offline reconstruction, is discussed. The use of the calibration samples to measure the detector PID performance, and the efficiency of PID requirements across a large range of decay channels, is described. Applications of the calibration samples in data-quality monitoring and validation procedures are also detailed.
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LHCb reports the first upper limits on B0 → K+π−τ+τ− and Bs0 → K+K−τ+τ− branching fractions, with recast limits of 2.8×10−4 on B0 → K*(892)0 τ+τ− at 95% CL that improve prior bounds by an order of magnitude.
First observation of Λ_b^0 → Λ p p-bar with 5.1σ significance and relative branching fraction (5.1 ± 1.3(stat) ± 0.3(syst)) × 10^{-2} to the reference mode Λ_b^0 → Λ K^+ K^-.
LHCb observes 3.2 sigma evidence for B+ -> pi+ e+ e- with measured branching fraction (2.4 +0.9 -0.8 +0.4 -0.2) x 10^-8, consistent with Standard Model.
A new charm-strange resonance D_s1(2933)^+ with J^P=1^+ is observed at >10 sigma in B^0 to D+ D- K+ pi- decays, with measured mass 2933 MeV and width 72 MeV.
Relative branching fraction B(B0 → Λc+ Λc- KS0)/B(B+ → Λc+ Λc- K+) measured as 0.53 ± 0.05 ± 0.05 with 3.9σ evidence for Ξc(2923)+ and Ξc(2939)+ resonances consistent with isospin partners.
Charged-hadron distributions in heavy-flavor jets differ from light-quark jets in ways consistent with dead-cone suppression and hard fragmentation of the heavy hadron.
R_K*0 is measured as 1.08^{+0.14}_{-0.12}(stat) ± 0.07(syst) for q² > 14 GeV²/c⁴ in B⁰ → K*⁰ ℓ⁺ℓ⁻ decays, consistent with the Standard Model.
citing papers explorer
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First evidence of the $B_s^0\rightarrow K^-\pi^+\gamma$ decay
LHCb reports the first experimental evidence for the Bs0 to K- pi+ gamma decay with 3.5 sigma significance and measures its branching fraction ratio to the B0 decay in two mass ranges.
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Searches for $B^0\to K^+\pi^-\tau^+\tau^-$ and $B_s^0\to K^+K^-\tau^+\tau^-$ decays
LHCb reports the first upper limits on B0 → K+π−τ+τ− and Bs0 → K+K−τ+τ− branching fractions, with recast limits of 2.8×10−4 on B0 → K*(892)0 τ+τ− at 95% CL that improve prior bounds by an order of magnitude.
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Observation of the charmless purely baryonic decay $\mathinner{\mathit{\Lambda}^0_b\!\to \mathit{\Lambda} p \overline{p}}$
First observation of Λ_b^0 → Λ p p-bar with 5.1σ significance and relative branching fraction (5.1 ± 1.3(stat) ± 0.3(syst)) × 10^{-2} to the reference mode Λ_b^0 → Λ K^+ K^-.
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First evidence of the decay $B^+\to\pi^+ e^+ e^-$
LHCb observes 3.2 sigma evidence for B+ -> pi+ e+ e- with measured branching fraction (2.4 +0.9 -0.8 +0.4 -0.2) x 10^-8, consistent with Standard Model.
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Observation of a new excited charm-strange meson $D_{s1}(2933)^+$ in $B^0\to D^+ D^- K^+ \pi^-$ decays
A new charm-strange resonance D_s1(2933)^+ with J^P=1^+ is observed at >10 sigma in B^0 to D+ D- K+ pi- decays, with measured mass 2933 MeV and width 72 MeV.
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Study of the $B^0 \to \Lambda_c^+ \bar{\Lambda}_c^- K_S^0$ decay
Relative branching fraction B(B0 → Λc+ Λc- KS0)/B(B+ → Λc+ Λc- K+) measured as 0.53 ± 0.05 ± 0.05 with 3.9σ evidence for Ξc(2923)+ and Ξc(2939)+ resonances consistent with isospin partners.
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Measurement of charged-hadron distributions in heavy-flavor jets in proton-proton collisions at $\sqrt{s}$=13 TeV
Charged-hadron distributions in heavy-flavor jets differ from light-quark jets in ways consistent with dead-cone suppression and hard fragmentation of the heavy hadron.
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Test of lepton flavour universality with $B^0\to K^{*0}\ell^+\ell^-$ decays at large dilepton invariant mass
R_K*0 is measured as 1.08^{+0.14}_{-0.12}(stat) ± 0.07(syst) for q² > 14 GeV²/c⁴ in B⁰ → K*⁰ ℓ⁺ℓ⁻ decays, consistent with the Standard Model.