# PH-EP Articles

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

2016-04-13
15:15
 Search for the Standard Model Higgs boson decaying into $b\bar{b}$ produced in association with top quarks decaying hadronically in $pp$ collisions at $\sqrt{s}$=8 TeV with the ATLAS detector / ATLAS Collaboration A search for Higgs boson production in association with a pair of top quarks ($t\bar{t}H$) is performed, where the Higgs boson decays to $b\bar{b}$, and both top quarks decay hadronically. The data used correspond to an integrated luminosity of 20.3 fb$^{-1}$ of $pp$ collisions at $\sqrt{s}=8$ TeV collected with the ATLAS detector at the Large Hadron Collider. [...] arXiv:1604.03812; CERN-EP-2016-058.- Geneva : CERN, 2016 - 48 p. - Published in : J. High Energy Phys. 05 (2016) 160 Fulltext: PDF; External links: Previous draft version; 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

2016-03-23
17:44
 Beam-induced and cosmic-ray backgrounds observed in the ATLAS detector during the LHC 2012 proton-proton running period / ATLAS Collaboration This paper discusses various observations on beam-induced and cosmic-ray backgrounds in the ATLAS detector during the LHC 2012 proton-proton run. Building on published results based on 2011 data, the correlations between background and residual pressure of the beam vacuum are revisited. [...] arXiv:1603.09202; CERN-EP-2016-029.- Geneva : CERN, 2016 - 65 p. - Published in : JINST 11 (2016) P05013 Fulltext: PDF; External links: Previous draft version; Preprint

2016-03-21
23:25
 Measurement of the top quark mass using charged particles in $pp$ in collisions at $\sqrt{s}=$ 8 TeV / CMS Collaboration A novel technique for measuring the mass of the top quark that uses only the kinematic properties of its charged decay products is presented. Top quark pair events with final states with one or two charged leptons and hadronic jets are selected from the data set of 8 TeV proton-proton collisions, corresponding to an integrated luminosity of 19.7 fb$^{-1}$. [...] arXiv:1603.06536; CMS-TOP-12-030-003; CERN-EP-2016-062.- Geneva : CERN, 2016 - 46 p. - Published in : Phys. Rev. D 93 (2016) 092006 APS Open Access article: PDF; Fulltext: PDF; External link: Preprint

2016-03-17
17:28
 Muon reconstruction performance of the ATLAS detector in proton--proton collision data at $\sqrt{s}$=13 TeV / ATLAS Collaboration This article documents the performance of the ATLAS muon identification and reconstruction using the first LHC dataset recorded at $\sqrt{s}$ = 13 TeV in 2015. Using a large sample of $J/\psi\to\mu\mu$ and $Z\to\mu\mu$ decays from 3.2 fb$^{-1}$ of $pp$ collision data, measurements of the reconstruction efficiency, as well as of the momentum scale and resolution, are presented and compared to Monte Carlo simulations. [...] arXiv:1603.05598; CERN-EP-2016-033.- Geneva : CERN, 2016 - 45 p. - Published in : Eur. Phys. J. C 76 (2016) 292 Fulltext: PDF; Springer Open Access article: PDF; External links: Previous draft version; Preprint