EP Articles

Senast inlagda poster:
2019-01-22
15:12
 Measurement of the mass and production rate of $\Xi_b^-$ baryons / LHCb Collaboration The first measurement of the production rate of $\Xi_b^-$ baryons in $pp$ collisions relative to that of $\Lambda_b^0$ baryons is reported, using data samples collected by the LHCb experiment, and corresponding to integrated luminosities of 1, 2 and 1.6~fb$^{-1}$ at $\sqrt{s}=7,~8$ and 13~TeV, respectively. In the kinematic region $2 < \eta < 6$ and $p_{\rm T}<20$~GeV/\it{c}, we measure \begin{align*} \frac{f_{\Xi_b^-}}{f_{\Lambda_b^0}}\frac{\mathcal B(\Xi_b^-\to J/\psi\Xi^-)}{\mathcal B(\Lambda_b^0\to J/\psi\Lambda)} &= (10.8\pm0.9\pm0.8)\times10^{-2}~~[\sqrt{s}=7,8~TeV],\\ \frac{f_{\Xi_b^-}}{f_{\Lambda_b^0}}\frac{\mathcal B(\Xi_b^-\to J/\psi\Xi^-)}{\mathcal B(\Lambda_b^0\to J/\psi\Lambda)} &= (13.1\pm1.1\pm1.0)\times10^{-2}~~[\sqrt{s}=13~TeV], \end{align*} where $f_{\Xi_b^-}$ and $f_{\Lambda_b^0}$ are the fragmentation fractions of $b$ quarks into $\Xi_b^-$ and $\Lambda_b^0$ baryons, respectively, $\mathcal B$ represents branching fractions, and the uncertainties are due to statistical and experimental systematic sources. [...] arXiv:1901.07075; LHCb-PAPER-2018-047; CERN-EP-2018-348; LHCB-PAPER-2018-047.- Geneva : CERN, 2019-03-22 - 21 p. - Published in : Phys. Rev. D 99 (2019) 052006 Article from SCOAP3: PDF; Fulltext: PDF; Related data file(s): ZIP;

2018-11-22
12:02
 Search for $CP$ violation through an amplitude analysis of $D^0\rightarrow K^+ K^- \pi^+ \pi^-$ decays / LHCb Collaboration A search for $CP$ violation in the Cabibbo-suppressed $D^0 \rightarrow K^+ K^- \pi^+ \pi^-$ decay mode is performed using an amplitude analysis. The measurement uses a sample of $pp$ collisions recorded by the LHCb experiment during 2011 and 2012, corresponding to an integrated luminosity of 3.0 fb$^{-1}$. [...] arXiv:1811.08304; LHCb-PAPER-2018-041; CERN-EP-2018-299; CERN-EP-2018-299.- Geneva : CERN, 2019-02-20 - 33 p. - Published in : JHEP 02 (2019) 126 Additional files: ZIP; Article from SCOAP3: PDF; Fulltext: 1811.08304 - PDF; LHCb-PAPER-2018-041 - PDF; Related data file(s): ZIP; Supplementary information: ZIP;

2018-10-18
14:47
 Study of $\Upsilon$ production in $p$Pb collisions at $\sqrt{s_{NN}}=8.16$ TeV / LHCb Collaboration The production of $\Upsilon (nS)$ mesons ($n=1,2,3$) in $p$Pb and Pb$p$ collisions at a centre-of-mass energy per nucleon pair $\sqrt{s_{NN}}=8.16$ TeV is measured by the LHCb experiment, using a data sample corresponding to an integrated luminosity of 31.8 nb$^{-1}$. The $\Upsilon (nS)$ mesons are reconstructed through their decays into two opposite-sign muons. [...] arXiv:1810.07655; LHCb-PAPER-2018-035; CERN-EP-2018-267.- Geneva : CERN, 2018-11-29 - 37 p. - Published in : JHEP 11 (2018) 194 Article from SCOAP3: PDF; Fulltext: 1810.07655 - PDF; LHCb-PAPER-2018-035 - PDF; Related data file(s): ZIP;

2018-10-17
15:45
 Measurement of the charm-mixing parameter $y_{CP}$ / LHCb Collaboration A measurement of the charm-mixing parameter $y_{CP}$ using $D^0 \to K^+ K^-$, $D^0 \to \pi^+ \pi^-$, and $D^0 \to K^- \pi^+$ decays is reported. The $D^0$ mesons are required to originate from semimuonic decays of $B^-$ and $\overline{B}^0$ mesons. [...] arXiv:1810.06874; CERN-EP-2018-270 and LHCb-PAPER-2018-038; LHCb-PAPER-2018-038; CERN-EP-2018-270; LHCB-PAPER-2018-038.- Geneva : CERN, 2019-01-08 - 10 p. - Published in : 10.1103/PhysRevLett.122.011802 Article from SCOAP3: PDF; Fulltext: 1810.06874 - PDF; Paper 2018 038 - PDF; Related data file(s): ZIP; Supplementary information: ZIP; External link: Figures, tables and other information

2018-10-05
14:01
 Observation of two resonances in the $\Lambda_b^0 \pi^\pm$ systems and precise measurement of $\Sigma_b^\pm$ and $\Sigma_b^{*\pm}$ properties / LHCb Collaboration The first observation of two structures consistent with resonances in the final states $\Lambda_b^0 \pi^-$ and $\Lambda_b^0 \pi^+$ is reported using samples of $pp$ collision data collected by the LHCb experiment at $\sqrt{s} = 7$ and $8$ TeV, corresponding to an integrated luminosity of 3 $\mathrm{fb}^{-1}$. The ground states $\Sigma_b^\pm$ and $\Sigma_b^{*\pm}$ are also confirmed and their masses and widths are precisely measured.. arXiv:1809.07752; LHCb-PAPER-2018-032; CERN-EP-2018-243; LHCB-PAPER-2018-032.- Geneva : CERN, 2019-01-12 - 9 p. - Published in : Phys. Rev. Lett. 122 (2019) 012001 Article from SCOAP3: PDF; Fulltext: 1809.07752 - PDF; 2018-032 - PDF; Related data file(s): ZIP; External link: Figures, tables and other information

2018-09-21
11:55
 Evidence for an $\eta_c(1S) \pi^-$ resonance in $B^0 \to \eta_c(1S) K^+\pi^-$ decays / LHCb Collaboration A Dalitz plot analysis of $B^0 \to \eta_c(1S) K^+\pi^-$ decays is performed using data samples of $pp$ collisions collected with the LHCb detector at centre-of-mass energies of $\sqrt{s}=7,~8$ and $13$ TeV, corresponding to a total integrated luminosity of $4.7~\text{fb}^{-1}$. A satisfactory description of the data is obtained when including a contribution representing an exotic $\eta_c(1S) \pi^-$ resonant state. [...] arXiv:1809.07416; LHCb-PAPER-2018-034; CERN-EP-2018-245.- Geneva : CERN, 2018-12-17 - 39 p. - Published in : Eur. Phys. J. C 78 (2018) 1019 Article from SCOAP3: PDF; Fulltext: 1809.07416 - PDF; LHCb-PAPER-2018-034 - PDF; Related data file(s): ZIP; External link: Figures, tables and other information

2018-08-24
11:51
 Search for lepton-flavour-violating decays of Higgs-like bosons / LHCb Collaboration A search is presented for a Higgs-like boson with mass in the range 45 to 195 GeV/$c^2$ decaying into a muon and a tau lepton. The dataset consists of proton-proton interactions at a centre-of-mass energy of 8 TeV, collected by the LHCb experiment, corresponding to an integrated luminosity of 2 fb$^{-1}$. [...] arXiv:1808.07135; CERN-EP-2018-210; LHCb-PAPER-2018-030.- Geneva : CERN, 2018-12-12 - 20 p. - Published in : 10.1140/epjc/s10052-018-6386-8 Article from SCOAP3: PDF; Fulltext: LHCb-PAPER-2018-030 - PDF; 1808.07135 - PDF; Related data file(s): ZIP; External link: Figures, tables and other information

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 Article from SCOAP3: PDF; Fulltext: 1808.06127 - PDF; LHCb-PAPER-2018-031 - PDF; Fulltext from Publisher: 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: LHCb-PAPER-2018-029 - PDF; 1808.00264 - 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: 1807.06544 - PDF; LHCb-PAPER-2018-025 - PDF; Preprint: PDF; Related data file(s): ZIP; Supplementary Information: ZIP; External link: Figures, tables and other information