# EP Articles

Posledne pridané:
2016-05-04
08:04
 Measurement of forward $W$ and $Z$ boson production in association with jets in proton-proton collisions at $\sqrt{s}=8$ TeV / LHCb collaboration The production of $W$ and $Z$ bosons in association with jets is studied in the forward region of proton-proton collisions collected at a centre-of-mass energy of 8~TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98 $\pm$ 0.02 fb$^{-1}$. The $W$ boson is identified using its decay to a muon and a neutrino, while the $Z$ boson is identified through its decay to a muon pair. [...] arXiv:1605.00951; CERN-EP-2016-092; LHCB-PAPER-2016-011.- Geneva : CERN, 2016 - 27 p. - Published in : J. High Energy Phys. 05 (2016) 131 Fulltext: PDF; Related data file(s): ZIP; Related supplementary data file(s): ZIP; Springer Open Access article: PDF; External link: Preprint

2016-04-14
09:52
 Measurement of the properties of the $\Xi_b^{*0}$ baryon / LHCb Collaboration We perform a search for near-threshold $\Xi_b^0$ resonances decaying to $\Xi_b^- \pi^+$ in a sample of proton-proton collision data corresponding to an integrated luminosity of 3 fb$^{-1}$ collected by the LHCb experiment. We observe one resonant state, with the following properties: \begin{eqnarray*} m(\Xi_b^{*0}) - m(\Xi_b^-) - m(\pi^+) &=& 15.727 \pm 0.068 \, (\mathrm{stat}) \pm 0.023 \, (\mathrm{syst}) \, \mathrm{MeV}/c^2, \\ \Gamma(\Xi_b^{*0}) &=& 0.90 \pm 0.16 \, (\mathrm{stat}) \pm 0.08 \, (\mathrm{syst}) \, \mathrm{MeV} [...] arXiv:1604.03896; LHCB-PAPER-2016-010; CERN-EP-2016-082.- Geneva : CERN, 2016 - 18 p. - Published in : J. High Energy Phys. 05 (2016) 161 Fulltext: PDF; Related data file(s): ZIP; Springer Open Access article: PDF; External link: Preprint

2016-04-07
08:52
 Measurement of the mass and lifetime of the $\Omega_b^-$ baryon / LHCb collaboration A proton-proton collision data sample, corresponding to an integrated luminosity of 3 fb$^{-1}$ collected by LHCb at $\sqrt{s}=7$ and 8 TeV, is used to reconstruct $63\pm9$ $\Omega_b^-\to\Omega_c^0\pi^-$, $\Omega_c^0\to pK^-K^-\pi^+$ decays. Using the $\Xi_b^-\to\Xi_c^0\pi^-$, $\Xi_c^0\to pK^-K^-\pi^+$ decay mode for calibration, the lifetime ratio and absolute lifetime of the $\Omega_b^-$ baryon are measured to be \begin{align*} \frac{\tau_{\Omega_b^-}}{\tau_{\Xi_b^-}} &= 1.11\pm0.16\pm0.03, \\ \tau_{\Omega_b^-} &= 1.78\pm0.26\pm0.04\pm0.05~{\rm ps}, \end{align*} where the uncertainties are statistical, systematic and from the calibration mode (for $\tau_{\Omega_b^-}$ only). [...] arXiv:1604.01412; CERN-EP-2016-081; LHCB-PAPER-2016-008.- Geneva : CERN, 2016 - 21 p. - Published in : Phys. Rev. D 93 (2016) 092007 APS Open Access article: PD; Fulltext: PDF; Related data file(s): ZIP; External link: Preprint

2016-03-30
08:08
 Search for resonances in the mass distribution of jet pairs with one or two jets identified as $b$-jets in proton--proton collisions at $\sqrt{s}=13$ TeV with the ATLAS detector / ATLAS Collaboration Searches for high-mass resonances in the dijet invariant mass spectrum with one or two jets identified as $b$-jets are performed using an integrated luminosity of $3.2$ fb$^{-1}$ of proton--proton collisions with a centre-of-mass energy of $\sqrt{s}=13$ TeV recorded by the ATLAS detector at the Large Hadron Collider. No evidence of anomalous phenomena is observed in the data, which are used to exclude, at 95% credibility level, excited $b^{*}$ quarks with masses from 1.1 TeV to 2.1 TeV and leptophobic $Z'$ bosons with masses from 1.1 TeV to 1.5 TeV. [...] arXiv:1603.08791; CERN-EP-2016-066.- Geneva : CERN, 2016 - 32 p. - Published in : Phys. Lett. B 759 (2016) 229-246 Elsevier Open Access article: PDF; Fulltext: PDF; External links: Preprint; Previous draft version

2016-03-24
08:21
 Search for $B_c^+$ decays to the $p\overline p\pi^+$ final state / LHCb collaboration A search for the decays of the $B_c^+$ meson to $p\overline p\pi^+$ is performed for the first time using a data sample corresponding to an integrated luminosity of 3.0 $\mathrm{fb}^{-1}$ collected by the LHCb experiment in $pp$ collisions at centre-of-mass energies of $7$ and $8$ TeV. No signal is found and an upper limit, at 95$\%$ confidence level, is set, $\frac{f_c}{f_u}\times\mathcal{B}(B_c^+\to p\overline p\pi^+)<3.6\times10^{-8}$ in the kinematic region $m(p\overline p)<2.85\mathrm{\,Ge\kern -0.1em V\!/}c^2$, $p_{\rm T}(B)<20\mathrm{\,Ge\kern -0.1em V\!/}c$ and $2.0< {y}(B)<4.5$, where $\mathcal{B}$ is the branching fraction and $f_c$ ($f_u$) is the fragmentation fraction of the $b$ quark into a $B_c^+$ ($B^+$) meson.. arXiv:1603.07037; LHCB-PAPER-2016-001; CERN-EP-2016-072.- Geneva : CERN, 2016 - 17 p. - Published in : Phys. Lett. B 759 (2016) 313-321 Elsevier Open Acesss article: PDF; Fulltext: PDF; Related data file(s): ZIP; External link: Preprint

2016-03-24
08:21
 Observation of $\Lambda_b^0 \to \psi(2S)pK^-$ and $\Lambda_b^0 \to J/\psi \pi^+ \pi^- pK^-$ decays and a measurement of the $\Lambda_b^0$ baryon mass / LHCb collaboration The decays $\Lambda_b^0 \to \psi(2S)pK^-$ and $\Lambda_b^0 \to J/\psi \pi^+ \pi^- pK^-$ are observed in a data sample corresponding to an integrated luminosity of 3fb$^{-1}$, collected in proton-proton collisions at 7 and 8TeV centre-of-mass energies by the LHCb detector. The $\psi(2S)$ mesons are reconstructed through the decay modes $\psi(2S)\to\mu^+\mu^-$ and $\psi(2S)\to J/\psi\pi^+\pi^-$ [...] arXiv:1603.06961; CERN-EP-2016-070; LHCB-PAPER-2015-060.- Geneva : CERN, 2016 - 20 p. - Published in : J. High Energy Phys. 05 (2016) 132 Fulltext: PDF; Related data file(s): ZIP; Related supplementary data file(s): ZIP; Springer Open Access article: PDF; External link: Preprint

2016-03-10
12:57
 Observation of the $\Lambda_b^0\to\Lambda\phi$ decay / LHCb collaboration The $\Lambda_b^0\to\Lambda\phi$ decay is observed using data corresponding to an integrated luminosity of 3.0fb$^{-1}$ recorded by the LHCb experiment. The decay proceeds at leading order via a $b\to s\bar{s}s$ loop transition and is therefore sensitive to the possible presence of particles beyond the Standard Model. [...] arXiv:1603.02870; LHCB-PAPER-2016-002; CERN-EP-2016-047.- Geneva : CERN, 2016 - 22 p. - Published in : Phys.Lett. B 759 (2016) 282-292 Fulltext: PDF; Related data file(s): ZIP; External link: Preprint

2016-03-08
16:18
 Observation of $B^0_s\to\bar{D}^0 K^0_S$ and evidence for $B^0_s\to\bar{D}^{*0} K^0_S$ decays / LHCb Collaboration The first observation of the $B^0_s\to\bar{D}^0 K^0_S$ decay mode and evidence for the $B^0_s\to\bar{D}^{*0} K^0_S$ decay mode are reported. The data sample corresponds to an integrated luminosity of 3.0 $\text{fb}^{-1}$ collected in $pp$ collisions by LHCb at center-of-mass energies of 7 and 8 TeV. [...] arXiv:1603.02408; LHCB-PAPER-2015-050; CERN-EP-2016-053.- Geneva : CERN, 2016 - 16 p. - Published in : Phys. Rev. Lett. 116 (2016) 161802 APS Open Access article: PDF; Fulltext: PDF; Related data file(s): ZIP; External link: Preprint

2016-03-02
11:22
 Observations of $\Lambda_b^0 \to \Lambda K^+\pi^-$ and $\Lambda_b^0 \to \Lambda K^+K^-$ decays and searches for other $\Lambda_b^0$ and $\Xi_b^0$ decays to $\Lambda h^+h^{\prime -}$ final states / LHCb collaboration A search is performed for the charmless three-body decays of the $\Lambda_b^0$ and $\Xi_b^0$ baryons to the final states $\Lambda h^+h^{\prime -}$, where $h^{(\prime)} = \pi$ or $K$. The analysis is based on a data sample, corresponding to an integrated luminosity of $3 \rm fb^{-1}$ of $pp$ collisions, collected by the LHCb experiment. [...] arXiv:1603.00413; CERN-EP-2016-038; LHCB-PAPER-2016-004.- Geneva : CERN, 2016 - 24 p. - Published in : J. High Energy Phys. 05 (2016) 081 Fulltext: PDF; Related data file(s): ZIP; Related supplementary data file(s): ZIP; Springer Open Access article: PDF; External link: Preprint

2016-02-25
08:58
 Measurement of the $B_{s}^{0} \rightarrow D_{s}^{(*)+}D_{s}^{(*)-}$ branching fractions / LHCb collaboration The branching fraction of the decay $B_{s}^{0} \rightarrow D_{s}^{(*)+}D_{s}^{(*)-}$ is measured using $pp$ collision data corresponding to an integrated luminosity of $1.0fb^{-1}$, collected using the LHCb detector at a centre-of-mass energy of $7$TeV. It is found to be \begin{align*} {\mathcal{B}}(B_{s}^{0}\rightarrow~D_{s}^{(*)+}D_{s}^{(*)-}) = (3.05 \pm 0.10 \pm 0.20 \pm 0.34)\%, \end{align*} where the uncertainties are statistical, systematic, and due to the normalisation channel, respectively. [...] arXiv:1602.07543; CERN-EP-2016-028; LHCB-PAPER-2015-053.- Geneva : CERN, 2016 - 20 p. - Published in : Phys. Rev. D 93 (2016) 092008 APS Open Access article: PDF; Fulltext: PDF; Related data file(s): ZIP; External link: Preprint