PH-EP Articles

2014-11-27
08:06
 Measurement of the lifetime of the $B_c^+$ meson using the $B_c^+ \rightarrow J/\psi\pi^+$ decay mode / LHCb collaboration The difference in total widths between the $B_c^+$ and $B^+$ mesons is measured using 3.0fb$^{-1}$ of data collected by the LHCb experiment in 7 and 8 TeV centre-of-mass energy proton-proton collisions at the LHC. Through the study of the time evolution of $B_c^+ \rightarrow J/\psi \pi^+$ and $B^+\rightarrow J/\psi K^+$ decays, the width difference is measured to be $\Delta\Gamma \equiv \Gamma_{B_c^+} - \Gamma_{B^+} = 4.46 \pm 0.14 \pm 0.07mm^{-1}c,$ where the first uncertainty is statistical and the second systematic. [...] arXiv:1411.6899; CERN-PH-EP-2014-283; LHCB-PAPER-2014-060.- Geneva : CERN, 2015 - 19 p. - Published in : Phys. Lett. B 742 (2015) 29-37 Fulltext: PDF; Related data file(s): ZIP; External link: Preprint

2014-11-25
10:28
 Search for long-lived neutral particles decaying to quark-antiquark pairs in proton-proton collisions at $\sqrt{s}$ = 8 TeV / CMS Collaboration A search is performed for long-lived massive neutral particles decaying to quark-antiquark pairs. The experimental signature is a distinctive topology of a pair of jets, originating at a secondary vertex. [...] arXiv:1411.6530; CMS-EXO-12-038; CERN-PH-EP-2014-256.- Geneva : CERN, 2015 - 35 p. - Published in : Phys. Rev. D 91 (2015) 012007 Fulltext: PDF; External link: Preprint

2014-11-24
17:23
 Searches for heavy long-lived charged particles with the ATLAS detector in proton--proton collisions at $\sqrt{s}$ = 8 TeV / ATLAS Collaboration Searches for heavy long-lived charged particles are performed using a data sample of 19.8 fb$^{-1}$ from proton--proton collisions at a centre-of-mass energy of $\sqrt{s}$ = 8 TeV collected by the ATLAS detector at the Large Hadron Collider. No excess is observed above the estimated background and limits are placed on the mass of long-lived particles in various supersymmetric models. [...] arXiv:1411.6795; CERN-PH-EP-2014-252.- Geneva : CERN, 2015 - 37 p. - Published in : J. High Energy Phys. 01 (2015) 068 Fulltext: PDF; External links: Previous draft version; Preprint

2014-11-21
22:07
 Search for disappearing tracks in proton-proton collisions at $\sqrt{s}$ = 8 TeV / CMS Collaboration A search is presented for long-lived charged particles that decay within the CMS detector and produce the signature of a disappearing track. Disappearing tracks are identified as those with little or no associated calorimeter energy deposits and with missing hits in the outer layers of the tracker. [...] arXiv:1411.6006; CMS-EXO-12-034; CERN-PH-EP-2014-273.- Geneva : CERN, 2015 - 37 p. - Published in : J. High Energy Phys. 01 (2015) 096 Fulltext: PDF; External link: Preprint

2014-11-19
09:27
 Observation of two new $\Xi_b^-$ baryon resonances / LHCb collaboration Two structures are observed close to the kinematic threshold in the $\Xi_b^0\pi^-$ mass spectrum in a sample of proton-proton collision data, corresponding to an integrated luminosity of 3.0 fb$^{-1}$ recorded by the LHCb experiment. In the quark model, two baryonic resonances with quark content $bds$ are expected in this mass region: the spin-parity $J^P = \frac{1}{2}^+$ and $J^P=\frac{3}{2}^+$ states, denoted $\Xi_b^{\prime -}$ and $\Xi_b^{*-}$. [...] arXiv:1411.4849; CERN-PH-EP-2014-279; LHCB-PAPER-2014-061.- Geneva : CERN, 2015 - 17 p. - Published in : Phys. Rev. Lett. 114 (2015) 062004 APS Open Access article: PDF; Fulltext: PDF; Related data file(s): ZIP; Related supplementary data file(s): ZIP; External link: Preprint

2014-11-06
08:30
 Measurement of the Z+b-jet cross-section in pp collisions at $\sqrt{s}=7{\mathrm{\,Te\kern -0.1em V}}$ in the forward region / LHCb collaboration The associated production of a Z boson or an off-shell photon $\gamma^*$ with a bottom quark in the forward region is studied using proton-proton collisions at a centre-of-mass energy of $7{\mathrm{\,Te\kern -0.1em V}}$. The Z bosons are reconstructed in the ${\text{Z}/\gamma^*}\rightarrow{\mu^{+}\mu^{-}}$ final state from muons with a transverse momentum larger than $20{\mathrm{\,Ge\kern -0.1em V}}$, while two transverse momentum thresholds are considered for jets ($10{\mathrm{\,Ge\kern -0.1em V}}$ and $20{\mathrm{\,Ge\kern -0.1em V}}$). [...] arXiv:1411.1264; LHCB-PAPER-2014-055; CERN-PH-EP-2014-267.- Geneva : CERN, 2015 - 17 p. - Published in : J. High Energy Phys. 01 (2015) 064 Fulltext: PDF; Related data file(s): ZIP; External link: Preprint

2014-11-05
16:34
 Search for new phenomena in events with a photon and missing transverse momentum in $pp$ collisions at $\sqrt{s}=8$ TeV with the ATLAS detector / ATLAS Collaboration Results of a search for new phenomena in events with an energetic photon and large missing transverse momentum with the ATLAS experiment at the LHC are reported. Data were collected in proton--proton collisions at a center-of-mass energy of 8 TeV and correspond to an integrated luminosity of 20.3 fb$^{-1}$. [...] arXiv:1411.1559; CERN-PH-EP-2014-245.- Geneva : CERN, 2015 - 14 p. - Published in : Phys. Rev. D 91 (2015) 012008 Fulltext: PDF; External links: Previous draft version; Preprint

2014-11-05
11:17
 Study of $\eta-\eta'$ mixing from measurement of $B^0_{(s)}\to J/\psi\eta^{(')}$ decay rates / LHCb Collaboration A study of $B^0$and $B^0_s$ meson decays into $J/\psi\eta$ and $J/\psi\eta^{\prime}$ final states is performed using a data set of proton-proton collisions at centre-of-mass energies of 7 and 8TeV, collected by the LHCb experiment and corresponding to 3.0fb$^{-1}$ of integrated luminosity. The decay $B^0 \rightarrow J/\psi \eta^{\prime}$ is observed for the first time. [...] arXiv:1411.0943; LHCB-PAPER-2014-056; CERN-PH-EP-2014-266.- Geneva : CERN, 2015 - 26 p. - Published in : J. High Energy Phys. 01 (2015) 024 Fulltext: PDF; Related data file(s): ZIP; External link: Preprint

2014-11-03
16:16
 Performance of the CMS missing transverse momentum reconstruction in pp data at $\sqrt{s}$ = 8 TeV / CMS Collaboration The performance of missing transverse energy reconstruction algorithms is presented using $\sqrt{s}$ = 8TeV proton-proton (pp) data collected with the CMS detector. Events with anomalous missing transverse energy are studied, and the performance of algorithms used to identify and remove these events is presented. [...] arXiv:1411.0511; CMS-JME-13-003; CERN-PH-EP-2014-246.- Geneva : CERN, 2015 - Published in : J. Instrum. 10 (2015) P02006 Fulltext: PDF; IOP Open Access article: PDF; External link: Preprint

2014-10-27
00:29
 Measurement of the $WW+WZ$ cross section and limits on anomalous triple gauge couplings using final states with one lepton, missing transverse momentum, and two jets with the ATLAS detector at $\sqrt{\rm{s}} = 7$ TeV / ATLAS Collaboration The production of a $W$ boson decaying to $e\nu$ or $\mu\nu$ in association with a $W$ or $Z$ boson decaying to two jets is studied using $4.6~\mathrm{fb}^{-1}$ of proton--proton collision data at $\sqrt{\rm{s}} = 7$ TeV recorded with the ATLAS detector at the LHC. The combined $WW+WZ$ cross section is measured with a significance of 3.4$\sigma$ and is found to be $68 \pm 7 \ \mathrm{(stat.)} \pm 19 \ \mathrm{(syst.)} \ pb$, in agreement with the Standard Model expectation of $61.1 \pm 2.2 \ \mathrm{pb}$. [...] CERN-PH-EP-2014-244; arXiv:1410.7238.- Geneva : CERN, 2015 - 25 p. - Published in : J. High Energy Phys. 01 (2015) 049 Fulltext: PDF; External links: Previous draft version; Preprint