PH-EP Articles

2015-07-14
08:36
 Observation of $J/\psi p$ resonances consistent with pentaquark states in ${\Lambda_b^0\to J/\psi K^-p}$ decays / LHCb collaboration Observations of exotic structures in the $J/\psi p$ channel, that we refer to as pentaquark-charmonium states, in $\Lambda_b^0\to J/\psi K^- p$ decays are presented. The data sample corresponds to an integrated luminosity of 3/fb acquired with the LHCb detector from 7 and 8 TeV pp collisions. [...] arXiv:1507.03414; CERN-PH-EP-2015-153; LHCB-PAPER-2015-029.- Geneva : CERN, 2015 - 48 p. - Published in : Phys. Rev. Lett. 115 (2015) 072001 APS Open Access article: PDF; Fulltext: PDF; Related data file(s): ZIP; Related supplementary data file: PDF; Related supplementary data file(s): ZIP; External link: Preprint

2015-06-30
08:05
 Angular analysis and differential branching fraction of the decay $B^0_s\to\phi\mu^+\mu^-$ / LHCb collaboration An angular analysis and a measurement of the differential branching fraction of the decay $B^0_s\to\phi\mu^+\mu^-$ are presented, using data corresponding to an integrated luminosity of $3.0\, {\rm fb}^{-1}$ of $pp$ collisions recorded by the LHCb experiment at $\sqrt{s} = 7$ and $8\, {\rm TeV}$. Measurements are reported as a function of $q^{2}$, the square of the dimuon invariant mass and results of the angular analysis are found to be consistent with the Standard Model. [...] arXiv:1506.08777; CERN-PH-EP-2015-145; LHCB-PAPER-2015-023.- Geneva : CERN, 2015 - 37 p. - Published in : J. High Energy Phys. 09 (2015) 179 Fulltext: PDF; Related data file(s): ZIP; Related supplementary data file(s): ZIP; External link: Preprint

2015-06-23
14:09
 Measurement of exclusive $\gamma\gamma\rightarrow \ell^+\ell^-$ production in proton--proton collisions at $\sqrt{s} = 7$ TeV with the ATLAS detector / ATLAS Collaboration This Letter reports a measurement of the exclusive $\gamma\gamma\rightarrow \ell^+\ell^- (\ell=e, \mu)$ cross-section in proton--proton collisions at a centre-of-mass energy of 7 TeV by the ATLAS experiment at the LHC, based on an integrated luminosity of $4.6$ fb$^{-1}$. For the electron or muon pairs satisfying exclusive selection criteria, a fit to the dilepton acoplanarity distribution is used to extract the fiducial cross-sections. [...] arXiv:1506.07098; CERN-PH-EP-2015-134.- Geneva : CERN, 2015 - 12 p. - Published in : Phys. Lett. B 749 (2015) 242-261 Fulltext: PDF; External links: Previous draft version; Preprint

2015-06-22
14:26
 Study of $(W/Z)H$ production and Higgs boson couplings using $H \rightarrow WW^{\ast}$ decays with the ATLAS detector / ATLAS Collaboration A search for Higgs boson production in association with a $W$ or $Z$ boson, in the $H \rightarrow WW^{\ast}$ decay channel, is performed with a data sample collected with the ATLAS detector at the LHC in proton-proton collisions at centre-of-mass energies $\sqrt{s}=7$ TeV and 8 TeV, corresponding to integrated luminosities of 4.5 ${\rm fb}^{-1}$ and 20.3 ${\rm fb}^{-1}$, respectively. The $WH$ production mode is studied in two-lepton and three-lepton final states, while two-lepton and four-lepton final states are used to search for the $ZH$ production mode. [...] arXiv:1506.06641; CERN-PH-EP-2015-104.- Geneva : CERN, 2015 - 48 p. - Published in : J. High Energy Phys. 08 (2015) 137 Fulltext: PDF; External links: Previous draft version; Preprint

2015-06-19
14:29
 Search for heavy Majorana neutrinos with the ATLAS detector in pp collisions at $\sqrt{s} = 8$ TeV / ATLAS Collaboration A search for heavy Majorana neutrinos in events containing a pair of high-$p_{\mathrm{T}}$ leptons of the same charge and high-$p_{\mathrm{T}}$ jets is presented. The search uses $20.3 \mathrm{fb}^{-1}$ of $pp$ collision data collected with the ATLAS detector at the CERN Large Hadron Collider with a centre-of-mass energy of $\sqrt{s} = 8$ TeV. [...] arXiv:1506.06020; CERN-PH-EP-2015-070.- Geneva : CERN, 2015 - 28 p. - Published in : J. High Energy Phys. 07 (2015) 162 Fulltext: PDF; Springer Open Access article: PDF; External links: Previous draft version; Preprint

2015-06-19
13:51
 Search for the associated production of the Higgs boson with a top quark pair in multilepton final states with the ATLAS detector / ATLAS Collaboration A search for the associated production of the Higgs boson with a top quark pair is performed in multilepton final states using 20.3 fb$^{-1}$ of proton-proton collision data recorded by the ATLAS experiment at $\sqrt{s}=8$ TeV at the Large Hadron Collider. Five final states, targeting the decays $H\to WW^*$, $\tau\tau$, and $ZZ^*$, are examined for the presence of the Standard Model (SM) Higgs boson: two same-charge light leptons ($e$ or $\mu$) without a hadronically decaying $\tau$ lepton; three light leptons; two same-charge light leptons with a hadronically decaying $\tau$ lepton; four light leptons; and one light lepton and two hadronically decaying $\tau$ leptons. [...] arXiv:1506.05988; CERN-PH-EP-2015-109.- Geneva : CERN, 2015 - 14 p. - Published in : Phys. Lett. B 749 (2015) 519-541 Fulltext: PDF; External links: Previous draft version; Preprint

2015-06-05
02:48
 Search for type-III Seesaw heavy leptons in $pp$ collisions at $\sqrt{s}= 8$ TeV with the ATLAS Detector / ATLAS Collaboration A search for the pair-production of heavy leptons ($N^0,L^{\pm}$) predicted by the type-III seesaw theory formulated to explain the origin of small neutrino masses is presented. The decay channels $N^0\rightarrow W^{\pm}l^{\mp}$ ($\ell = e, \mu, \tau$) and $L^{\pm}\rightarrow W^\pm \nu$ ($\nu=\nu_e, \nu_\mu, \nu_\tau$) are considered. [...] arXiv:1506.01839; CERN-PH-EP-2015-094.- Geneva : CERN, 2015 - 22 p. - Published in : Phys. Rev. D 92 (2015) 032001 Fulltext: PDF; External links: Previous draft version; Preprint

2015-06-02
23:10
 Search for the standard model Higgs boson produced through vector boson fusion and decaying to $\mathrm{b\bar{b}}$ / CMS Collaboration A first search is reported for a standard model Higgs boson (H) that is produced through vector boson fusion and decays to a bottom-quark pair. Two data samples, corresponding to integrated luminosities of 19.8 fb$^{-1}$ and 18.3 fb$^{-1}$ of proton-proton collisions at $\sqrt{s} =$ 8 TeV were selected for this channel at the CERN LHC. [...] arXiv:1506.01010; CMS-HIG-14-004; CERN-PH-EP-2015-121.- Geneva : CERN, 2015 - 42 p. - Published in : Phys. Rev. D 92 (2015) 032008 Fulltext: PDF; External link: Preprint

2015-06-01
07:58
 Measurement of the exclusive $\Upsilon$ production cross-section in $pp$ collisions at $\sqrt{s}=$7 TeV and 8 TeV / LHCb collaboration A study is presented of central exclusive production of $\Upsilon(nS)$ states, where the $\Upsilon(nS)$ resonances decay to the $\mu^+\mu^-$ final state, using $pp$ collision data recorded by the LHCb experiment. The cross-section is measured in the rapidity range $2 < y (\Upsilon) < 4.5$ where the muons are reconstructed in the pseudorapidity range $2<\eta(\mu^\pm)<4.5$. [...] arXiv:1505.08139; LHCB-PAPER-2015-011; CERN-PH-EP-2015-123.- Geneva : CERN, 2015 - 21 p. - Published in : J. High Energy Phys. 09 (2015) 084 Fulltext: PDF; Related data file(s): ZIP; External link: Preprint

2015-05-28
08:14
 Measurement of the forward $Z$ boson production cross-section in $pp$ collisions at $\sqrt{s}$ = 7 TeV / LHCb collaboration A measurement of the production cross-section for $Z$ bosons that decay to muons is presented. The data were recorded by the LHCb detector during $pp$ collisions at a centre-of-mass energy of 7 TeV, and correspond to an integrated luminosity of 1.0 fb$^{-1}$ [...] arXiv:1505.07024; LHCB-PAPER-2015-001; CERN-PH-EP-2015-102.- Geneva : CERN, 2015 - 41 p. - Published in : J. High Energy Phys. 08 (2015) 039 Fulltext: PDF; Related data file(s): ZIP; Related supplementary data file(s): ZIP; External link: Preprint