Author Correction:A consensus protocol for functional connectivity analysis in the rat brain

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Measurement of D0−D‾0D^0-\overline{D}^0 mixing and search for CPCP violation with D0→K+π−D^0\rightarrow K^+\pi^- decays

A measurement of the time-dependent ratio of the $D^0\rightarrow K^+\pi^-$ to $\overline{D}^0\rightarrow K^+\pi^-$ decay rates is reported. The analysis uses a sample of proton-proton collisions corresponding to an integrated luminosity of 6 fb$^-1$ recorded by the LHCb experiment from 2015 through 2018 at a center-of-mass energy of 13 TeV. The $D^0$ meson is required to originate from a $D^{*+}\rightarrow D^0\pi^+$ decay, such that its flavor at production is inferred from the charge of the accompanying pion. The measurement is performed simultaneously for the $K^+\pi^-$ and $K^-\pi^+$ final states, allowing both mixing and $CP$-violation parameters to be determined. The value of the ratio of the decay rates at production is determined to be $R_{K\pi} = (343.1 \pm 2.0) \times 10^{-5}$. The mixing parameters are measured to be $c_{K\pi} = (51.4 \pm 3.5) \times 10^{-4}$ and $c_{K\pi}^{\prime} = (13 \pm 4) \times 10^{-6}$, where $\sqrt{R_{K\pi}}c_{K\pi}$ is the linear coefficient of the expansion of the ratio as a function of decay time in units of the $D^0$ lifetime, and $c_{K\pi}^{\prime}$ is the quadratic coefficient, both averaged between the $K^+\pi^-$ and $K^-\pi^+$ final states. The precision is improved relative to the previous best measurement by approximately 60%. No evidence for $CP$ violation is found.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/Publications/LHCbProjectPublic/LHCb-PAPER-2024-008.htm

Search for the rare decay of charmed baryon Λc+ into the pμ+μ- final state

A search for the nonresonant Λc+→pμ+μ- decay is performed using proton-proton collision data recorded at a center-of-mass energy of 13 TeV by the LHCb experiment, corresponding to an integrated luminosity of 5.4 fb-1. No evidence for the decay is found in the dimuon invariant-mass regions where the expected contributions of resonances is subdominant. The upper limit on the branching fraction of the Λc+→pμ+μ- decay is determined to be 2.9(3.2)×10-8 at 90%(95%) confidence level. The branching fractions in the dimuon invariant-mass regions dominated by the η, ρ and ω resonances are also determined

Search for resonance-enhanced CP and angular asymmetries in the Λc+→pμ+μ− decay at LHCb

The first measurement of the CP asymmetry of the decay rate (ACP) and the CP average (ΣAFB) and CP asymmetry (ΔAFB) of the forward-backward asymmetry in the muon system of Λþ c → pμþμ− decays is reported. The measurement is performed using a data sample of proton-proton collisions, recorded by the LHCb experiment from 2016 to 2018 at a center-of-mass energy of 13 TeV, which corresponds to an integrated luminosity of 5.4 fb−1. The asymmetries are measured in two regions of dimuon mass near the φ-meson mass peak. The dimuon-mass integrated results are ACP 1⁄4 ð−1.1 4.0 0.5Þ%, ΣAFB 1⁄4 ð3.9 4.0 0.6Þ%, ΔAFB 1⁄4 ð3.1 4.0 0.4Þ%, where the first uncertainty is statistical and the second systematic. The results are consistent with the conservation of CP symmetry and the Standard Model expectations

Search for the lepton-flavor violating decay Bs0 →φμ±τ

A search for the lepton-flavor violating decays Bs0→φμ±τ is presented, using a sample of proton-proton collisions at center-of-mass energies of 7, 8, and 13 TeV, collected with the LHCb detector and corresponding to a total integrated luminosity of 9 fb-1. The τ leptons are selected using decays with three charged pions. No significant excess is observed, and an upper limit on the branching fraction is determined to be B(Bs0→φμ±τ)<1.0×10-5 at 90% confidence level

Search for D0 meson decays to π+π−e+e− and K+K−e+e− final states

A search for D0 meson decays to the πþπ−eþe− and KþK−eþe− final states is reported using a sample of proton-proton collisions collected by the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 6 fb−1. The decay D0 → πþπ−eþe− 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. The corresponding branching fractions are measured relative to the D0 → K−π−1⁄2eþe−ρ0=ω decay, where the two electrons are consistent with coming from the decay of a ρ0 or ω meson. No evidence is found for the D0 → KþK−eþe− decay and world-best limits are set on its branching fraction. The results are compared to, and found to be consistent with, the branching fractions of the D0 → πþπ−μþμ− and D0 → KþK−μþμ− decays recently measured by LHCb and confirm lepton universality at the current precision

Test of Lepton Flavor Universality with B+→K+π+π−l+l− Decays

The first test of lepton flavor universality between muons and electrons using Bþ → Kþπþπ−lþl− (l 1⁄4 e, μ) decays is presented. The measurement is performed with data from proton-proton collisions collected by the LHCb experiment at center-of-mass energies of 7, 8, and 13 TeV, corresponding to an integrated luminosity of 9 fb−1. The ratio of branching fractions between Bþ → Kþπþπ−eþe− and Bþ → Kþπþπ−μþμ− decays is measured in the dilepton invariant-mass-squared range 1.1 < q2 < 7.0 GeV2=c4 and is found to be R−1 Kππ 1⁄4 1.31þ0.18 −0.17 ðstatÞ þ0.12 −0.09 ðsystÞ, in agreement with the standard model prediction. The first observation of the Bþ → Kþπþπ−eþe− decay is also reporte

Probing the nature of the χc1(3872)\chi_{c1}(3872) state using radiative decays

The radiative decays $\chi_{c1}(3872)\rightarrow\psi(2S)\gamma$ and $\chi_{c1}(3872)\rightarrow J/\psi\gamma$ are used to probe the~nature of the~$\chi_{c1}(3872)$ state using proton-proton collision data collected with the LHCb detector, corresponding to an~integrated luminosity of~9fb$^{-1}$. Using the~$B^+\rightarrow \chi_{c1}(3872)K^+$decay, the $\chi_{c1}(3872)\rightarrow \psi(2S)\gamma$ process is observed for the first time and the ratio of its partial width to that of the $\chi_{c1}(3872)\rightarrow J/\psi\gamma$ decay is measured to be $$\frac{\Gamma_{\chi_{c1}(3872)\rightarrow \psi(2S)\gamma}} {\Gamma_{\chi_{c1}(3872)\rightarrow J/\psi\gamma}} = 1.67 \pm 0.21 \pm 0.12 \pm0.04 ,$$ where the first uncertainty is statistical, the second systematic and the third is due to the uncertainties on the branching fractions of the $\psi(2S)$ and $J/\psi$ mesons. The measured ratio makes the interpretation of the $\chi_{c1}(3872)$ state as a~pure $D^0\bar{D}^{*0}+\bar{D}^0D^{*0}$ molecule questionable and strongly indicates a sizeable compact charmonium or tetraquark component within the $\chi_{c1}(3872)$ state.Comment: 31 pages, 2 figures. All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2024-015.html (LHCb public pages

Search for Bc+→π+μ+μ−B_c^+\to\pi^+\mu^+\mu^- decays and measurement of the branching fraction ratio B(Bc+→ψ(2S)π+)/B(Bc+→J/ψπ+){\cal B}(B_c^+\to\psi(2S)\pi^+)/{\cal B}(B_c^+\to J/\psi \pi^+)

The first search for nonresonant $B_c^+\to\pi^+\mu^+\mu^-$ decays is reported. The analysis uses proton-proton collision data collected with the LHCb detector between 2011 and 2018, corresponding to an integrated luminosity of 9 fb$^{-1}$. No evidence for an excess of signal events over background is observed and an upper limit is set on the branching fraction ratio ${\cal B}(B_c^+\to\pi^+\mu^+\mu^-)/{\cal B}(B_c^+\to J/\psi \pi^+) < 2.1\times 10^{-4}$ at $90\%$ confidence level. Additionally, an updated measurement of the ratio of the $B_c^+\to\psi(2S)\pi^+$ and $B_c^+\to J/\psi \pi^+$ branching fractions is reported. The ratio ${\cal B}(B_c^+\to\psi(2S)\pi^+)/{\cal B}(B_c^+\to J/\psi \pi^+)$ is measured to be $0.254\pm 0.018 \pm 0.003 \pm 0.005$, where the first uncertainty is statistical, the second systematic, and the third is due to the uncertainties on the branching fractions of the leptonic $J/\psi$ and $\psi(2S)$ decays. This measurement is the most precise to date and is consistent with previous LHCb results.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2023-037.html (LHCb public pages

Measurement of the CKM angle γ in B± → DK*(892)± decays

Measurements of CP observables and the CKM angle γ are performed in B± → DK∗ (892)± decays, where D represents a superposition of D0 and D 0 states, using the LHCb dataset collected during Run 1 (2011–2012) and Run 2 (2015–2018). A study of this channel is presented with the D meson reconstructed in two-body fnal states K±π ∓, K+K− and π +π −; four-body fnal states K±π ∓π ±π ∓ and π +π −π +π −; and threebody fnal states K0 S π +π − and K0 SK+K−. This analysis includes the frst observation of the suppressed B± → [π ±K∓]DK∗± and B± → [π ±K∓π ±π ∓]DK∗± decays. The combined result gives γ = (63 ± 13)◦