# EP Articles

2017-08-22
09:20
 Search for baryon-number-violating $\Xi_b^0$ oscillations / LHCb Collaboration A search for baryon-number-violating $\Xi_b^0$ oscillations is performed with a sample of $pp$ collision data recorded by the LHCb experiment, corresponding to an integrated luminosity of 3 fb$^{-1}$. The baryon number at the moment of production is identified by requiring that the $\Xi_b^0$ come from the decay of a resonance $\Xi_b^{*-} \to \Xi_b^0 \pi^-$ or $\Xi_b^{\prime-} \to \Xi_b^0 \pi^-$, and the baryon number at the moment of decay is identified from the final state using the decays $\Xi_b^0 \to \Xi_c^+ \pi^-, ~ \Xi_c^+ \to p K^- \pi^+$. [...] LHCB-PAPER-2017-023; CERN-EP-2017-189; arXiv:1708.05808; LHCB-PAPER-2017-023.- Geneva : CERN, 2017-11-03 - 9 p. - Published in : Phys. Rev. Lett. 119 (2017) 181807 Fulltext: PDF; Preprint: PDF; Related data file(s): ZIP; Supplementary information: ZIP;

2017-07-27
14:24
 Observation of $D^0$ meson decays to $\pi^+\pi^-\mu^+\mu^-$ and $K^+K^-\mu^+\mu^-$ final states / LHCb Collaboration The first observation of the $D^0 \to \pi^+\pi^-\mu^+\mu^-$ and $D^0 \to K^+K^-\mu^+\mu^-$ decays is reported using a sample of proton-proton collisions collected by LHCb at a center-of-mass energy of 8$\,$TeV, and corresponding to 2$\,$fb$^{-1}$ of integrated luminosity. The corresponding branching fractions are measured using as normalization the decay $D^0 \to K^- \pi^+[\mu^+\mu^-]_{\rho^0/\omega}$, where the two muons are consistent with coming from the decay of a $\rho^0$ or $\omega$ meson. [...] LHCB-PAPER-2017-019; CERN-EP-2017-167; arXiv:1707.08377.- 2017-10-31 - 10 p. - Published in : Phys. Rev. Lett. 119 (2017) 181805 Fulltext: 10.1103_PhysRevLett.119.181805 - PDF; LHCb-PAPER-2017-019 - PDF; Preprint: PDF; Related data file(s): ZIP; Supplementary information: ZIP;

2017-07-07
07:35
 Observation of the doubly charmed baryon $\Xi_{cc}^{++}$ / LHCb Collaboration A highly significant structure is observed in the $\Lambda_c^+K^-\pi^+\pi^+$ mass spectrum, where the $\Lambda_c^+$ baryon is reconstructed in the decay mode $pK^-\pi^+$. The structure is consistent with originating from a weakly decaying particle, identified as the doubly charmed baryon $\Xi_{cc}^{++}$. [...] LHCB-PAPER-2017-018; CERN-EP-2017-156; arXiv:1707.01621.- 2017-09-11 - 10 p. - Published in : Phys. Rev. Lett. 119 (2017) 112001 Fulltext: LHCb-PAPER-2017-018 - PDF; 10.1103_PhysRevLett.119.112001 - PDF; Preprint: PDF; Related data file(s): ZIP; Supplementary information: ZIP; External links: conference slides; INTERACTIONS

2017-06-24
09:59
 Prompt and nonprompt J/$\psi$ production and nuclear modification in $p$Pb collisions at $\sqrt{s_{\text{NN}}}= 8.16$ TeV / LHCb Collaboration The production of J/$\psi$ mesons is studied in proton-lead collisions at the centre-of-mass energy per nucleon pair $\sqrt{s_{\text{NN}}}=8.16$ TeV with the LHCb detector at the LHC. The double differential cross-sections of prompt and nonprompt J/$\psi$ production are measured as functions of the J/$\psi$ transverse momentum and rapidity in the nucleon-nucleon centre-of-mass frame. [...] LHCB-PAPER-2017-014; CERN-EP-2017-122; arXiv:1706.07122; LHCB-PAPER-2017-014; EP-2017-122.- Geneva : CERN, 2017-11-10 - 20 p. - Published in : Phys. Lett. B 774 (2017) 159-178 Article from SCOAP3: PDF; Fulltext: PDF; Preprint: PDF; Related data files: ZIP;

2017-06-24
09:59
 Study of charmonium production in ${b}$-hadron decays and first evidence for the decay ${{{B}} ^0_{{s}}} \!\rightarrow \phi \phi \phi$ / LHCb Collaboration Using decays to $\phi$-meson pairs, the inclusive production of charmonium states in $b$-hadron decays is studied with $pp$ collision data corresponding to an integrated luminosity of $3.0fb^{-1}$, collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. Denoting by $B_C\equiv B(b\to CX)\times B(C\to\phi\phi)$ the inclusive branching fraction of a $b$ hadron to a charmonium state $C$ that decays into a pair of $\phi$ mesons, ratios $R^{C1}_{C2}\equiv B_{C1}/B_{C2}$ are determined as $R^{\chi_{c0}}_{\eta_c(1S)}=0.147\pm0.023\pm0.011$, $R^{\chi_{c1}}_{\eta_c (1S)}=0.073\pm0.016\pm0.006$, $R^{\chi_{c2}}_{\eta_c (1S)}=0.081\pm0.013\pm0.005$, $R^{\chi_{c1}}_{\chi_{c0}}=0.50\pm0.11\pm0.01$, $R^{\chi_{c2}}_{\chi_{c0}}=0.56\pm0.10\pm0.01$ and $R^{\eta_c (2S)}_{\eta_c(1S)}=0.040\pm0.011\pm0.004$. [...] LHCB-PAPER-2017-007; CERN-EP-2017-099; arXiv:1706.07013; LHCB-PAPER-2017-007.- Springer, 2017-09-14 - 31 p. - Published in : Eur. Phys. J. C 77 (2017) 609 Article from SCOAP3: PDF; Fulltext: PDF; Preprint: PDF; Related data file(s): ZIP; Supplementary information: ZIP;

2017-05-18
09:34
 Test of lepton universality with $B^{0} \rightarrow K^{*0}\ell^{+}\ell^{-}$ decays / LHCb Collaboration A test of lepton universality, performed by measuring the ratio of the branching fractions of the $B^{0} \rightarrow K^{*0}\mu^{+}\mu^{-}$ and $B^{0} \rightarrow K^{*0}e^{+}e^{-}$ decays, $R_{K^{*0}}$, is presented. The $K^{*0}$ meson is reconstructed in the final state $K^{+}\pi^{-}$, which is required to have an invariant mass within 100$\mathrm{\,MeV}c^2$ of the known $K^{*}(892)^{0}$ mass. [...] LHCB-PAPER-2017-013; CERN-EP-2017-100; arXiv:1705.05802; LHCB-PAPER-2017-013.- Geneva : CERN, 2017-08-16 - Published in : JHEP 08 (2017) 055 Article from SCOAP3: PDF; Preprint: PDF; Related data file(s): ZIP;

2017-05-12
10:56
 Measurement of $B^{0}_{s}$ and $D^{-}_{s}$ meson lifetimes / LHCb Collaboration We report on a measurement of the flavor-specific $B^{0}_{s}$ lifetime and of the $D^{-}_{s}$ lifetime using proton-proton collisions at center-of-mass energies of 7 and 8 TeV, collected by the LHCb experiment and corresponding to 3.0 fb$^{-1}$ of integrated luminosity. Approximately 407 000 $B^{0}_{s} \rightarrow D^{(*)-}_{s} \mu^{+}\nu_\mu$ decays are partially reconstructed in the $K^{+}K^{-}\pi^{-}\mu^{+}$ final state. [...] CERN-EP-2017-070; LHCB-PAPER-2017-004; arXiv:1705.03475.- Geneva : CERN, 2017-09-08 - 10 p. - Published in : Phys. Rev. Lett. 119 (2017) 101801 Fulltext: PDF; Preprint: PDF; Related data file(s): ZIP; Supplementary material: PDF; Supplementary material (zip): ZIP;

2017-05-08
14:53
 Observation of five new narrow $\Omega_c^0$ states decaying to $\Xi^+_c K^-$ / LHCb Collaboration The $\Xi^+_c K^-$ mass spectrum is studied with a sample of $pp$ collision data corresponding to an integrated luminosity of 3.3 fb$^{-1}$, collected by the LHCb experiment. The $\Xi^+_c$ is reconstructed in the decay mode $pK^- \pi^+$. [...] LHCB-PAPER-2017-002; CERN-EP-2017-037; arXiv:1703.04639; LHCB-PAPER-2017-002.- Geneva : CERN, 2017-05-02 - 10 p. - Published in : Phys. Rev. Lett. 118 (2017) 182001 Fulltext: 10.1103_PhysRevLett.118.182001 - PDF; arXiv:1703.04639 - PDF; Preprint: PDF; Supplementary information: ZIP;

2017-05-02
11:15
 Resonances and $CP$ violation in $B_s^0$ and $\overline{B}_s^0 \to J/\psi K^+K^-$ decays in the mass region above the $\phi(1020)$ / LHCb Collaboration The decays of $B_s^0$ and $\overline{B}_s^0$ mesons into the $J/\psi K^+K^-$ final state are studied in the $K^+K^-$ mass region above the $\phi(1020)$ meson in order to determine the resonant substructure and measure the $CP$-violating phase, $\phi_s$, the decay width, $\Gamma_s$, and the width difference between light and heavy mass eigenstates, $\Delta\Gamma_s$. A decay-time dependent amplitude analysis is employed. [...] CERN-EP-2017-062; LHCB-PAPER-2017-008; arXiv:1704.08217; LHCB-PAPER-2017-008.- Geneva : CERN, 2017-08-09 - 28 p. - Published in : JHEP 08 (2017) 037 Article from SCOAP3: PDF; Figures: ZIP; Preprint: PDF; External link: Previous draft version

2017-04-27
14:36
 Observation of charmless baryonic decays $B^0_{(s)} \to p \overline{p} h^+ h^{\prime-}$ / LHCb Collaboration Decays of $B^0$ and $B_{s}^0$ mesons to the charmless baryonic final states $p \overline{p} h^+ h^{\prime-}$, where $h$ and $h^\prime$ each denote a kaon or a pion, are searched for using the LHCb detector. The analysis is based on a sample of proton-proton collision data collected at center-of-mass energies of $7$ and $8\,$TeV, corresponding to an integrated luminosity of $3\,$fb$^{-1}$. [...] LHCB-PAPER-2017-005; CERN-EP-2017-052; arXiv:1704.08497; LHCB-PAPER-2017-005.- Geneva : CERN, 2017-09-27 - 10 p. - Published in : Phys. Rev. D 96 (2017) 051103 Figures: ZIP; Fulltext: PDF; Preprint: PDF; Related data file(s): ZIP; External link: Previous draft version