# EP Articles

2021-11-08
11:29
 Study of ${\mathrm{B}}_{\mathrm{c}}^{+}$ decays to charmonia and three light hadrons / LHCb Collaboration Using proton-proton collision data, corresponding to an integrated luminosity of $9fb^{-1}$ collected with the LHCb detector, seven decay modes of the $B_c^+$ meson into a $J/\psi$ or $\psi(2S)$ meson and three charged hadrons, kaons or pions, are studied. The decays $B_c^+\rightarrow ( \psi(2S) \rightarrow J/\psi \pi^+ \pi^-)\pi^+$, $B_c^+\rightarrow \psi(2S)\pi^+\pi^+\pi^-$, $B_c^+\rightarrow J/\psi K^+\pi^+\pi^-$ and $B_c^+\rightarrow J/\psi K^+K^+K^-$ are observed for the first time, and evidence for the $B_c^+\rightarrow \psi(2S)K^+K^-\pi^+$ decay is found, where $J/\psi$ and $\psi(2S)$ mesons are reconstructed in their dimuon decay modes. [...] arXiv:2111.03001; CERN-EP-2021-216; LHCB-PAPER-2021-034.- Geneva : CERN, 2022-01-13 - 28 p. - Published in : JHEP 2201 (2022) 065 Fulltext: LHCb-PAPER-2021-034 - PDF; 2111.03001 - PDF; document - PDF; Related data file(s): ZIP;

2021-09-17
13:44
 Observation of the suppressed $\Lambda_b^0\to D p K^-$ decay with $D\to K^+ \pi^-$ and measurement of its $C\!P$ asymmetry / LHCb Collaboration A study of $\Lambda^0_b$ baryon decays to the $DpK^-$ final state is presented based on a proton-proton collision data sample corresponding to an integrated luminosity of 9fb$^{-1}$ collected with the LHCb detector. Two $\Lambda^0_b$ decays are considered, $\Lambda^0_b\to DpK^-$ with $D\to K^-\pi^+$ and $D\to K^+\pi^-$, where $D$ represents a superposition of $D^0$ and $\overline{D}^0$ states. [...] arXiv:2109.02621; CERN-EP-2021-179; LHCB-PAPER-2021-027.- 2021-12-01 - 14 p. - Published in : Phys. Rev. D 104 (2021) 112008 Fulltext: 2109.02621 - PDF; LHCb-PAPER-2021-027 - PDF; Fulltext from publisher: PDF; Related data file(s): ZIP;

2021-09-16
11:03
 Search for the doubly charmed baryon $\it{\Xi}_{cc}^{+}$ in the $\it{\Xi}_{c}^{+} \pi^{-} \pi^{+}$ final state / LHCb Collaboration A search for the doubly charmed baryon $\it{\Xi}_{cc}^{+}$ is performed in the $\it{\Xi}_{c}^{+} \pi^{-} \pi^{+}$ invariant-mass spectrum, where the $\it{\Xi}_{c}^{+}$ baryon is reconstructed in the $p K^{-} \pi^{+}$ final state. The study uses proton-proton collision data collected with the LHCb detector at a centre-of-mass energy of 13$\mathrm{\,Te\kern -0.1em V}$, corresponding to a total integrated luminosity of 5.4$\,\mathrm{fb}^{-1}$. [...] arXiv:2109.07292; CERN-EP-2021-155; LHCB-PAPER-2021-019.- Geneva : CERN, 2021 - 27 p. - Published in : JHEP 2112 (2021) 107 Fulltext: LHCb-PAPER-2021-019 - PDF; 2109.07292 - PDF; Fulltext from publisher: PDF; Related data file(s): ZIP; Supplementary information: ZIP;

2021-09-03
13:57
 Measurement of the $W$ boson mass / LHCb Collaboration The $W$ boson mass is measured using proton-proton collision data at $\sqrt{s}=13$ TeV corresponding to an integrated luminosity of 1.7 fb$^{-1}$ recorded during 2016 by the LHCb experiment. With a simultaneous fit of the muon $q/p_T$ distribution of a sample of $W \to \mu\nu$ decays and the $\phi^*$ distribution of a sample of $Z\to\mu\mu$ decays the $W$ boson mass is determined to be \begin{equation*} m_{W} = 80354 \pm 23_{\rm stat} \pm 10_{\rm exp} \pm 17_{\rm theory} \pm 9_{\rm PDF}~\mathrm{MeV}, \end{equation*} where uncertainties correspond to contributions from statistical, experimental systematic, theoretical and parton distribution function sources. [...] arXiv:2109.01113; CERN-EP-2021-170; LHCB-PAPER-2021-024.- Geneva : CERN, 2022-01-10 - 38 p. - Published in : JHEP 2201 (2022) 036 Fulltext: 2021-024 - PDF; 2109.01113 - PDF; document - PDF; Related data file(s): ZIP; Supplementary information: ZIP;

2021-09-02
11:54
 Updated search for $B_c^+$ decays to two charm mesons / LHCb Collaboration A data set corresponding to an integrated luminosity of $9 \text{\, fb}^{-1}$ of proton-proton collisions collected by the LHCb experiment has been analysed to search for $B_c^+ \to D^{(*)+}_{(s)} (\overline{D})^{(*)0}$ decays. The decays are fully or partially reconstructed, where one or two missing neutral pions or photons from the decay of an excited charm meson are allowed. [...] arXiv:2109.00488; LHCb-PAPER-2021-023; CERN-EP-2021-154; LHCB-PAPER-2021-023.- Geneva : CERN, 2021 - 23 p. - Published in : JHEP 2112 (2021) 117 Fulltext: PDF; Related data file(s): ZIP; Supplementary information: ZIP;

2021-09-02
11:51
 Measurement of $J/\psi$ production cross-sections in $pp$ collisions at $\sqrt{s}=5$ TeV / LHCb Collaboration The production cross-sections of $J/\psi$ mesons in proton-proton collisions at a centre-of-mass energy of $\sqrt{s}=5$ TeV are measured using a data sample corresponding to an integrated luminosity of $9.13\pm0.18~\text{pb}^{-1}$, collected by the LHCb experiment. The cross-sections are measured differentially as a function of transverse momentum, $p_{\text{T}}$, and rapidity, $y$, and separately for $J/\psi$ mesons produced promptly and from beauty hadron decays (nonprompt). [...] arXiv:2109.00220; LHCb-PAPER-2021-020,CERN-EP-2021-156; LHCB-PAPER-2021-020.- Geneva : CERN, 2021 - 34 p. - Published in : JHEP 2111 (2021) 181 Fulltext: PDF; Related data file(s): ZIP; Supplementary information: ZIP;

2021-07-29
17:06
 Angular analysis of the rare decay $B_s^0\to\phi\mu^+\mu^-$ / LHCb Collaboration The abstract for the paper is An angular analysis of the rare decay $B^0_s\rightarrow\phi\mu^+\mu^-$ is presented, using proton-proton collision data collected by the LHCb experiment at centre-of-mass energies of $7$, $8$ and $13~\rm{TeV}$, corresponding to an integrated luminosity of 8.4~$\rm{fb}^{-1}$. The observables describing the angular distributions of the decay $B^0_s\rightarrow\phi\mu^+\mu^-$ are determined in regions of $q^2$, the square of the dimuon invariant mass. [...] arXiv:2107.13428; LHCb-PAPER-2021-022; CERN-EP-2021-138; LHCB-PAPER-2021-022.- 2021-11-08 - 45 p. - Published in : JHEP 2111 (2021) 043 Fulltext: document - PDF; main (1) - PDF; 2107.13428 - PDF; Related data file(s): ZIP; Supplementary information: ZIP;

2021-07-23
14:23
 Observation of a $\Lambda_b^0-\overline{\Lambda}_b^0$ production asymmetry in proton-proton collisions at $\sqrt{s} = 7 \textrm{ and } 8\,\textrm{TeV}$ / LHCb Collaboration This article presents differential measurements of the asymmetry between $\Lambda_b^0$ and $\overline{\Lambda}_b^0$ baryon production rates in proton-proton collisions at centre-of-mass energies of $\sqrt{s}=7$ and $8\,\textrm{TeV}$ collected with the LHCb experiment, corresponding to an integrated luminosity of $3\,\textrm{fb}^{-1}$. The $\Lambda_b^0$ baryons are reconstructed through the inclusive semileptonic decay $\Lambda_b^0\rightarrow\Lambda_c^+\mu^-\overline{\nu}_{\mu}X$. [...] arXiv:2107.09593; LHCb-PAPER-2021-016; CERN-EP-2021-121; LHCB-PAPER-2021-016.- 2021-10-07 - 38 p. - Published in : JHEP 2110 (2021) 060 Fulltext: Fulltext from publisher - PDF; 2107.09593 - PDF; document - PDF; Preprint: PDF; Related data file(s): ZIP; Supplementary information: ZIP; External link: Previous draft version

2021-07-09
12:19
 Observation of excited $\Omega_c^0$ baryons in $\Omega_b^- \to \Xi_c^+ K^-\pi^-$decays / LHCb Collaboration The first observation of the $\Omega_b^-\to\Xi_c^+ K^- \pi^-$ decay is reported using proton-proton collision data at centre-of-mass energies of $7$, $8$ and $13\,\mathrm{TeV}$ collected by the LHCb experiment, corresponding to an integrated luminosity of $9\,\mathrm{fb}^{-1}$. Four excited $\Omega_c^0$ baryons are observed in the $\Xi_c^+ K^-$ mass projection of the $\Omega_b^-\to\Xi_c^+ K^- \pi^-$ decays with significance exceeding five standard deviations. [...] arXiv:2107.03419; CERN-EP-2021-109; LHCb-PAPER-2021-012; LHCB-PAPER-2021-012.- Geneva : CERN, 2021-11-01 - 28 p. - Published in : Phys. Rev. D 104 (2021) L091102 Fulltext: 2107.03419 - PDF; PhysRevD.104.L091102 - PDF; Related data file(s): ZIP;

2021-06-09
08:52
 Observation of the Mass Difference Between Neutral Charm-Meson Eigenstates / LHCb Collaboration A measurement of mixing and $C\!P$ violation in neutral charm mesons is performed using data reconstructed in proton-proton collisions collected by the LHCb experiment from 2016 to 2018, corresponding to an integrated luminosity of 5.4$\textrm{fb}^{-1}$. A total of $30.6$ million $D^{0}\rightarrow K^{0}_{\mathrm{S}}\pi^{+}\pi^{-}$ decays are analyzed using a method optimized for the measurement of the mass difference between neutral charm-meson eigenstates. [...] arXiv:2106.03744; LHCb-PAPER-2021-009; CERN-EP-2021-099; LHCB-PAPER-2021-009.- Geneva : CERN, 2021-09-07 - 12 p. - Published in : Phys. Rev. Lett. 127 (2021) 111801 Fulltext: LHCb-PAPER-2021-009_v3 - PDF; 2106.03744 - PDF; Fulltext from publisher: PDF; Related data file(s): ZIP; Supplementary information: ZIP;