# EP Articles

2018-08-21
10:21
 Measurement of antiproton production in ${\rm p He}$ collisions at $\sqrt{s_{NN}}=110$ GeV / LHCb Collaboration The cross-section for prompt antiproton production in collisions of protons with an energy of $6.5$ TeV incident on helium nuclei at rest is measured with the LHCb experiment from a data set corresponding to an integrated luminosity of $0.5 ~~\rm nb^{-1}$. The target is provided by injecting helium gas into the LHC beam line at the LHCb interaction point. [...] arXiv:1808.06127; LHCb-PAPER-2018-031; CERN-EP-2018-217.- Geneva : CERN, 2018-11-30 - 10 p. - Published in : Phys. Rev. Lett. 121 (2018) 222001 Fulltext: PDF; Related data file(s): ZIP; Supplementary information: ZIP; External link: Figures, tables and other information

2018-08-03
09:58
 Angular moments of the decay $\Lambda_b^0 \rightarrow \Lambda \mu^{+} \mu^{-}$ at low hadronic recoil / LHCb Collaboration An analysis of the angular distribution of the decay $\Lambda_b^0 \rightarrow \Lambda \mu^{+} \mu^{-}$ is presented, using data collected with the LHCb detector between 2011 and 2016 and corresponding to an integrated luminosity of approximately $5\,fb^{-1}$. Angular observables are determined using a moment analysis of the angular distribution at low hadronic recoil, corresponding to the dimuon invariant mass squared range $15 < q^{2} < 20\, GeV^2/c^4$. [...] arXiv:1808.00264; CERN-EP-2018-197; LHCb-PAPER-2018-029.- Geneva : CERN, 2018-09-26 - 27 p. - Published in : JHEP 09 (2018) 146 Article from SCOAP3: PDF; Fulltext: PDF; Related data file(s): ZIP; Supplementary information: ZIP; External link: Figures, tables and other information

2018-07-18
10:00
 Search for $C\!P$ violation in $\Lambda^0_b \to p K^-$ and $\Lambda^0_b \to p \pi^-$ decays / LHCb Collaboration A search for $C\!P$ violation in $\Lambda^0_b \to p K^-$ and $\Lambda^0_b \to p \pi^-$ decays is presented using a sample of $pp$ collisions collected with the LHCb detector and corresponding to an integrated luminosity of 3.0 fb$^{-1}$. The $C\!P$-violating asymmetries are measured to be $A_{\mathrm{CP}}^{pK^-} = -0.020 \pm 0.013\pm 0.019$ and $A_{\mathrm{CP}}^{p\pi^-} = -0.035 \pm 0.017 \pm 0.020$, and their difference $A_{\mathrm{CP}}^{pK^-}-A_{\mathrm{CP}}^{p\pi^-} = 0.014 \pm 0.022 \pm 0.010$, where the first uncertainties are statistical and the second systematic. [...] arXiv:1807.06544; LHCb-PAPER-2018-025; CERN-EP-2018-189.- Geneva : CERN, 2018-12-10 - 10 p. - Published in : Phys. Lett. B 787 (2018) 124-133 Article from SCOAP3: PDF; Fulltext: PDF; Preprint: PDF; Related data file(s): ZIP; Supplementary Information: ZIP; External link: Figures, tables and other information

2018-07-16
15:53
 Measurement of $\Upsilon$ production in $pp$ collisions at $\sqrt{s}$= 13 TeV / LHCb Collaboration The production cross-sections of $\Upsilon(1S)$, $\Upsilon(2S)$ and $\Upsilon(3S)$ mesons in proton-proton collisions at $\sqrt{s}$= 13 TeV are measured with a data sample corresponding to an integrated luminosity of $277 \pm 11$ $\rm pb^{-1}$ recorded by the LHCb experiment in 2015. The $\Upsilon$ mesons are reconstructed in the decay mode $\Upsilon\to\mu^{+}\mu^{-}$. [...] LHCB-PAPER-2018-002; CERN-EP-2018-054; arXiv:1804.09214; LHCB-PAPER-2018-002.- 2018-07-20 - 26 p. - Published in : JHEP 07 (2018) 134 Article from SCOAP3: PDF; Fulltext: PDF; Related data file(s): ZIP; External link: Figures, tables and other information

2018-07-06
10:57
 First observation of the doubly charmed baryon decay $\Xi_{cc}^{++} \rightarrow \Xi_{c}^{+} \pi^{+}$ / LHCb Collaboration The doubly charmed baryon decay $\Xi_{cc}^{++} \rightarrow \Xi_{c}^{+} \pi^{+}$ is observed for the first time, with a statistical significance of $5.9\sigma$, confirming a recent observation of the baryon in the $\Lambda_c^{+} K^{-} \pi^{+} \pi^{+}$ final state. The data sample used corresponds to an integrated luminosity of $1.7\,\mathrm{fb}^{-1}$, collected by the LHCb experiment in $pp$ collisions at a center-of-mass energy of $13\mathrm{\,Te\kern -0.1em V}$ [...] arXiv:1807.01919; LHCb-PAPER-2018-026; CERN-EP-2018-172; LHCB-PAPER-2018-026; LHCB-PAPER-2018-026.- Geneva : CERN, 2018-10-18 - 10 p. - Published in : Phys. Rev. Lett. 121 (2018) 162002 Article from SCOAP3: PDF; Fulltext: PDF; Fulltext from Publisher: PDF; Related data file(s): ZIP; Supplementary information: ZIP; External link: Figures, tables and other information

2018-07-06
10:51
 Measurement of the $\Omega_c^0$ baryon lifetime / LHCb Collaboration We report a measurement of the lifetime of the $\Omega_c^0$ baryon using proton-proton collision data at center-of-mass energies of 7 and 8~TeV, corresponding to an integrated luminosity of 3.0 fb$^{-1}$ collected by the LHCb experiment. The sample consists of about 1000 $\Omega_b^-\to\Omega_c^0\mu^-\bar{\nu}_{\mu} X$ signal decays, where the $\Omega_c^0$ baryon is detected in the $pK^-K^-\pi^+$ final state and $X$ represents possible additional undetected particles in the decay. [...] arXiv:1807.02024; LHCb-PAPER-2018-028; CERN-EP-2018-175; LHCB-PAPER-2018-028; LHCB-PAPER-2018-028.- Geneva : CERN, 2018-09-01 - 10 p. - Published in : Phys. Rev. Lett. 121 (2018) 092003 Article from SCOAP3: PDF; Fulltext: PDF; Fulltext from Publisher: PDF; Preprint: PDF; Related data file(s): ZIP; Supplementary information: ZIP; External link: Figures, tables and other information

2018-06-29
15:46
 Measurement of angular and CP asymmetries in $D^0\to\pi^+\pi^-\mu^+\mu^-$ and $D^0\to K^+K^-\mu^+\mu^-$ decays / LHCb Collaboration The first measurements of the forward-backward asymmetry of the dimuon pair ($A_{FB}$), the triple-product asymmetry ($A_{2\phi}$), and the charge-parity-conjugation asymmetry ($A_{CP}$), in $D^0\to\pi^+\pi^-\mu^+\mu^-$ and $D^0\to K^+K^-\mu^+\mu^-$ decays are reported. They are performed using data from proton-proton collisions collected with the LHCb experiment from 2011 to 2016, corresponding to a total integrated luminosity of 5 fb$^{-1}$. [...] arXiv:1806.10793; CERN-EP-2018-162; LHCb-PAPER-2018-020; LHCB-PAPER-2018-020.- Geneva : CERN, 2018-08-31 - 10 p. - Published in : Phys. Rev. Lett. 121 (2018) 091801 Article from SCOAP3: PDF; Fulltext: PDF; Fulltext from Publisher: PDF; Related data file(s): ZIP; Supplementary information: ZIP; External link: Figures, tables and other information

2018-06-28
12:03
 Observation of the decay $\overline{B_s^0} \rightarrow \chi_{c2} K^+ K^-$ in the $\phi$ mass region / LHCb Collaboration The $\overline{B_s^0} \rightarrow \chi_{c2} K^+ K^-$ decay mode is observed and its branching fraction relative to the corresponding $\chi_{c1}$ decay mode, in a $\pm 15 \textrm{MeV}/c^2$ window around the $\phi$ mass, is found to be $\frac{\mathcal{B}(\overline{B_s^0} \rightarrow \chi_{c2} K^+ K^-) }{ \mathcal{B}(\overline{B_s^0} \rightarrow \chi_{c1} K^+ K^-)} = (17.1 \pm 3.1 \pm 0.4 \pm 0.9)\%,$ where the first uncertainty is statistical, the second systematic and the third due to the knowledge of the branching fractions of radiative $\chi_c$ decays. The decay mode $\overline{B_s^0} \rightarrow \chi_{c1} K^+ K^-$ allows the $B_s^0$ mass to be measured as $m(B_s^0) = 5366.83 \pm 0.25 \pm 0.27 \, \textrm{MeV}/c^2,$ where the first uncertainty is statistical and the second systematic. [...] arXiv:1806.10576; LHCb-PAPER-2018-018; CERN-EP-2018-160; LHCB-PAPER-2018-018.- Geneva : CERN, 2018-08-29 - 20 p. - Published in : JHEP 08 (2018) 191 Article from SCOAP3: PDF; Fulltext: PDF; Related data file(s): ZIP; Supplementary information: ZIP; External link: Figures, tables and other information

2018-06-26
11:08
 Search for beautiful tetraquarks in the $\Upsilon(1S)\mu^+\mu^-$ invariant-mass spectrum / LHCb Collaboration The $\Upsilon(1S)\mu^+\mu^-$ invariant-mass distribution is investigated for a possible exotic meson state composed of two $b$ quarks and two $\overline{b}$ quarks, $X_{b\overline{b}b\overline{b}}$. The analysis is based on a data sample of $pp$ collisions recorded with the LHCb detector at centre-of-mass energies $\sqrt{s} =$ 7, 8 and 13 TeV, corresponding to an integrated luminosity of 6.3 fb$^{-1}$. [...] arXiv:1806.09707; LHCb-PAPER-2018-027; CERN-EP-2018-163; LHCB-PAPER-2018-027; LHCB-PAPER-2018-027.- Geneva : CERN, 2018-10-12 - 21 p. - Published in : JHEP 10 (2018) 086 Article from SCOAP3: PDF; Fulltext: PDF; Related data file(s): ZIP; External link: Figures, tables and other information

2018-06-21
14:15
 Observation of the decay $\Lambda^0_b\rightarrow\psi(2S)p\pi^-$ / LHCb Collaboration The Cabibbo-suppressed decay $\Lambda^0_b\rightarrow\psi(2S)p\pi^-$ is observed for the first time using a data sample collected by the LHCb experiment in proton-proton collisions corresponding to 1.0, 2.0 and 1.9fb$^{-1}$ of integrated luminosity at centre-of-mass energies of 7, 8 and 13TeV, respectively. The $\psi(2S)$ mesons are reconstructed in the $\mu^+\mu^-$ final state. [...] arXiv:1806.08084; CERN-EP-2018-156; LHCb-PAPER-2018-022; LHCB-PAPER-2018-022; LHCB-PAPER-2018-022.- Geneva : CERN, 2018-08-21 - 16 p. - Published in : JHEP 08 (2018) 131 Article from SCOAP3: PDF; Fulltext: PDF; Related data file(s): ZIP; Supplementary information: ZIP; External link: Figures, tables and other information