EP Articles

Posledne pridané:
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 $pK^- \pi^+$. [...] CERN-EP-2017-037; arXiv:1703.04639; LHCB-PAPER-2017-002.- Geneva : CERN, 2017 - Published in : Phys. Rev. Lett. 118 (2017) 182001 Supplementary information: ZIP; External links: 00001 Distribution of the reconstructed invariant mass $m(\Xicp \Km)$ for all candidates passing the likelihood ratio selection; the solid (red) curve shows the result of the fit, and the dashed (blue) line indicates the fitted background. The shaded (red) histogram shows the corresponding mass spectrum from the \Xicp sidebands and the shaded (light gray) distributions indicate the feed-down from partially reconstructed $\Omegares_\cquark(X)^0$ resonances.; 00002 Distribution of the reconstructed invariant mass $m(\Xicp \Km)$ for all candidates passing the likelihood ratio selection, shown as black points with error bars, and the wrong-sign $m(\Xicp \Kp)$ spectrum scaled by a factor of 0.95, shown as a solid (red) histogram.; 00000 Distribution of the reconstructed invariant mass $m(\pkpi)$ for all candidates in the inclusive \Xicp sample passing the likelihood ratio selection described in the text. The solid (red) curve shows the result of the fit, and the dashed (blue) line indicates the fitted background.; Fulltext

2017-03-20
12:28
 Measurement of the $B^0_s\to\mu^+\mu^-$ branching fraction and effective lifetime and search for $B^0\to\mu^+\mu^-$ decays / LHCb Collaboration A search for the rare decays $B^0_s\to\mu^+\mu^-$ and $B^0\to\mu^+\mu^-$ is performed at the LHCb experiment using data collected in $pp$ collisions corresponding to a total integrated luminosity of 4.4 fb$^{-1}$. An excess of $B^0_s\to\mu^+\mu^-$ decays is observed with a significance of 7.8 standard deviations, representing the first observation of this decay in a single experiment. [...] CERN-EP-2017-041; LHCB-PAPER-2017-001; arXiv:1703.05747; CERN-EP-2017-041-LHCB-PAPER-2017-001.- Geneva : CERN, 2017 - 19 p. - Published in : Phys. Rev. Lett. 118 (2017) 191801 APS Open Access Article: PDF; Fulltext: 10.1103_PhysRevLett.118.191801 - PDF; arXiv:1703.05747 - PDF; Related data file(s): ZIP; Related supplementary data file(s): ZIP;

2017-03-01
14:47
 Observation of the decay $\Lambda^0_b \to p K^- \mu^+ \mu^-$ and a search for $C\!P$ violation / LHCb Collaboration A search for CP violation in the decay Λ$_{b}^{0}$  → pK$^{−}$ μ$^{+}$ μ$^{−}$ is presented. This decay is mediated by flavour-changing neutral-current transitions in the Standard Model and is potentially sensitive to new sources of CP violation. [...] LHCB-PAPER-2016-059; CERN-EP-2017-032; arXiv:1703.00256.- Geneva : CERN, 2017-06-21 - 19 p. - Published in : JHEP 1706 (2017) 108 Fulltext: PDF; Related data file(s): ZIP; Related supplementary data file(s): ZIP;

2017-03-01
12:41
 Neutron capture cross section measurement of $^{238}$U at the n_TOF CERN facility in the energy region from 1 eV to 700 keV / n_TOF Collaboration The aim of this work is to provide a precise and accurate measurement of the $^{238}$U(n,$\gamma$) reaction cross section in the energy region from 1 eV to 700 keV. This reaction is of fundamental importance for the design calculations of nuclear reactors, governing the behaviour of the reactor core. [...] arXiv:1612.00200.- Bologna : Istituto Nazionale di Fisica Nucleare, 2016 - 14 p.

2017-02-20
09:47
 Test of an additive diquark spectator model for meson-baryon quasi-two-body reactions / Zralek, M (Nijmegen U.) ; Metzger, W J (Nijmegen U.) ; Van de Walle, R T (Nijmegen U.) ; Dionisi, C (CERN) ; Gurtu, A (CERN) ; Mazzucato, M (CERN) ; Foster, B (Oxford U.) /for the Amsterdam-CERN-Nijmegen-Oxford Collaboration 1978 Fulltext: PDF; In : Meeting on Exotic Resonances, Hiroshima, Japan, 1 - 2 Sep 1978, pp.131

2017-01-31
07:18
 Observation of the suppressed decay $\Lambda^{0}_{b}\rightarrow p\pi^{-}\mu^{+}\mu^{-}$ / LHCb Collaboration The suppressed decay $\Lambda^{0}_{b}\rightarrow p\pi^{-}\mu^{+}\mu^{-}$, excluding the $J/\psi$ and $\psi(2S)\rightarrow \mu^{+}\mu^{-}$ resonances, is observed for the first time with a significance of 5.5 standard deviations. The analysis is performed with proton-proton collision data corresponding to an integrated luminosity of $3\mathrm{fb}^{-1}$ collected with the LHCb experiment. [...] LHCB-PAPER-2016-049; CERN-EP-2016-312; arXiv:1701.08705.- Geneva : CERN, 2017 - 16 p. - Published in : JHEP 04 (2017) 029 Fulltext: PDF; Related data file(s): ZIP; Related supplementary data file(s): ZIP; Springer Open Access article: PDF;

2017-01-27
16:36
 Study of the $D^0 p$ amplitude in $\Lambda_b^0\to D^0 p \pi^-$ decays / LHCb Collaboration An amplitude analysis of the decay $\Lambda_b^0\to D^0 p \pi^-$ is performed in the part of the phase space containing resonances in the $D^0 p$ channel. The study is based on a data sample corresponding to an integrated luminosity of 3.0 fb$^{-1}$ of $pp$ collisions recorded by the LHCb experiment. [...] CERN-EP-2017-007; LHCB-PAPER-2016-061; arXiv:1701.07873.- Geneva : CERN, 2017 - 41 p. - Published in : JHEP 05 (2017) 030 Fulltext: PDF; Related data file(s): ZIP; Springer Open Access article: PDF;

2017-01-21
07:23
 Measurement of the $B^{\pm}$ production asymmetry and the $CP$ asymmetry in $B^{\pm} \to J/\psi K^{\pm}$ decays / LHCb Collaboration The $B^{\pm}$ meson production asymmetry in $pp$ collisions is measured using $B^+ \to \bar{D}^0 \pi^+$ decays. The data were recorded by the LHCb experiment during Run 1 of the LHC at centre-of-mass energies of $\sqrt{s}=$ 7 and 8 TeV [...] LHCB-PAPER-2016-054; CERN-EP-2016-325; arXiv:1701.05501; LHCB-PAPER-2016-054-CERN-EP-2016-325; LHCB-PAPER-2016-054.- Geneva : CERN, 2017 - 19 p. - Published in : Phys. Rev. D 95 (2017) 052005 APS Open Access article: PDF; Fulltext: arXiv:1701.05501 - PDF; 10.1103_PhysRevD.95.052005 - PDF; Related data file(s): ZIP; Related supplementary data file(s): ZIP;

2017-01-19
09:34
 Study of $J/\psi$ production in jets / LHCb Collaboration The production of $J/\psi$ mesons in jets is studied in the forward region of proton-proton collisions using data collected with the LHCb detector at a center-of-mass energy of 13 TeV. The fraction of the jet transverse momentum carried by the $J/\psi$ meson, $z \equiv p_{\rm T}(J/\psi)/p_{\rm T}({\rm jet})$, is measured using jets with $p_{\rm T}({\rm jet}) > 20$ GeV in the pseudorapidity range $2.5 < \eta({\rm jet}) < 4.0$. [...] LHCB-PAPER-2016-064; CERN-EP-2017-006; arXiv:1701.05116; LHCB-PAPER-2016-064.- Geneva : CERN, 2017 - 23 p. - Published in : Phys. Rev. Lett. 118 (2017) 192001 Fulltext: 10.1103_PhysRevLett.118.192001 - PDF; arXiv:1701.05116 - PDF; paper-2016-064 - PDF; Related data file(s): ZIP; Related supplementary data file(s): ZIP;

2017-01-09
11:46
 Measurement of $CP$ asymmetries in $D^{\pm}\rightarrow \eta^{\prime} \pi^{\pm}$ and $D_s^{\pm}\rightarrow \eta^{\prime} \pi^{\pm}$ decays / LHCb Collaboration A search for $CP$ violation in $D^{\pm}\rightarrow \eta^{\prime} \pi^{\pm}$ and $D^{\pm}_{s}\rightarrow \eta^{\prime} \pi^{\pm}$ decays is performed using proton-proton collision data, corresponding to an integrated luminosity of $3$ fb$^{-1}$, recorded by the LHCb experiment at centre-of-mass energies of $7$ and $8$ TeV. The measured $CP$-violating charge asymmetries are $A_{CP}(D^{\pm} \rightarrow \eta^{\prime} \pi^{\pm})=(-0.61\pm 0.72 \pm 0.53 \pm 0.12)\%$ and $A_{CP}(D^{\pm}_{s}\rightarrow \eta^{\prime} \pi^{\pm})=(-0.82\pm 0.36 \pm 0.22 \pm 0.27)\%$, where the first uncertainties are statistical, the second systematic, and the third are the uncertainties on the $A_{CP}(D^{\pm} \rightarrow K^0_S \pi^{\pm})$ and $A_{CP}(D^{\pm}_{s}\rightarrow \phi \pi^{\pm})$ measurements used for calibration. [...] LHCB-PAPER-2016-041; CERN-EP-2016-315; arXiv:1701.01871.- Geneva : CERN, 2017 - 20 p. - Published in : Phys. Lett. B 771 (2017) 21-30 Elsevier Open Access article: PDF; Fulltext: PDF; Related data file(s): ZIP; Related supplementary data file(s): ZIP;