The field inside a random distribution of parallel dipoles

We determine the probability distribution for the field inside a random uniform distribution of electric or magnetic dipoles. For parallel dipoles, simulations and an analytical derivation show that although the average contribution from any spherical shell around the probe position vanishes, the Levy stable distribution of the field is symmetric around a non-vanishing field amplitude. In addition we show how omission of contributions from a small volume around the probe leads to a field distribution with a vanishing mean, which, in the limit of vanishing excluded volume, converges to the shifted distribution.Comment: RevTeX, 4 pages, 3 figures. Submitted to Phys. Rev. Let

Photocatalytic Activity and Mechanical Properties of Cements Modified with TiO2/N

In this paper, studies of the mechanical properties and photocatalytic activity of new photoactive cement mortars are presented. The new building materials were obtained by the addition of 1, 3, and 5 wt % (based on the cement content) of nitrogen-modified titanium dioxide (TiO2/N) to the cement matrix. Photocatalytic active cement mortars were characterized by measuring the flexural and the compressive strength, the hydration heat, the zeta potential of the fresh state, and the initial and final setting time. Their photocatalytic activity was tested during NOx decomposition. The studies showed that TiO2/N gives the photoactivity of cement mortars during air purification with an additional positive effect on the mechanical properties of the hardened mortars. The addition of TiO2/N into the cement shortened the initial and final setting time, which was distinctly observed using 5 wt % of the photocatalyst in the cement matrix

Search for new particles in events with one lepton and missing transverse momentum in pp collisions at s√ = 8 TeV with the ATLAS detector

This paper presents a search for new particles in events with one lepton (electron or muon) and missing transverse momentum using 20.3 fb−1 of proton-proton collision data at s√ = 8 TeV recorded by the ATLAS experiment at the Large Hadron Collider. No significant excess beyond Standard Model expectations is observed. A W ′ with Sequential Standard Model couplings is excluded at the 95% confidence level for masses up to 3.24 TeV. Excited chiral bosons (W *) with equivalent coupling strengths are excluded for masses up to 3.21 TeV. In the framework of an effective field theory limits are also set on the dark matter-nucleon scattering cross-section as well as the mass scale M * of the unknown mediating interaction for dark matter pair production in association with a leptonically decaying W

Search for supersymmetry at √s= 8 TeV in final states with jets and two same-sign leptons or three leptons with the ATLAS detector

A search for strongly produced supersymmetric particles is conducted using signatures involving multiple energetic jets and either two isolated leptons (e or μ) with the same electric charge, or at least three isolated leptons. The search also utilises jets originating from b-quarks, missing transverse momentum and other observables to extend its sensitivity. The analysis uses a data sample corresponding to a total integrated luminosity of 20.3 fb-1 of √s = 8 TeV proton-proton collisions recorded with the ATLAS detector at the Large Hadron Collider in 2012. No deviation from the Standard Model expectation is observed. New or significantly improved exclusion limits are set on a wide variety of supersymmetric models in which the lightest squark can be of the first, second or third generations, and in which R-parity can be conserved or violated

Survival Analysis of Complete Veneer Crowns vs. Multisurface Restorations: A Dental School Patient Population

The purpose of this study was to compare the longevity of crowns versus large multisurface restorations in posterior teeth. The investigation used the treatment database at Virginia Commonwealth University School of Dentistry. The inclusion criteria for the final data set used for analysis were: only one restored tooth per patient, premolars with three or more restored surfaces, molars with four or more restored surfaces, molars and premolars restored with complete veneer metal crowns, or crowns veneered with metal and porcelain. The Kaplan-Meier approach was used to visualize the survival curves, and the Cox proportional hazards model was used for analysis of predictor variables. The investigation indicates crowns survive longer than large restorations and premolar restorations survive longer than molar restorations. The median survival for crowns exceeded 16.6 years, with the median survival of premolar restorations being 4.4 years and molar restorations 1.3 years. An interaction between age and treatment was discovered, with overall survival decreasing as patient age increases. The doctor supervising the treatment also affected survival with treatment supervised by specialists lasting longer than treatment supervised by nonspecialists

Search for quantum black hole production in high-invariant-mass lepton + jet final states using pp collisions at √s = 8 TeV and the ATLAS detector

A search is reported for a neutral Higgs boson in the decay channel H→Zγ, Z→ℓ +ℓ - (ℓ = e, μ), using 4.5 fb-1 of pp collisions at s=7 TeV and 20.3 fb-1 of pp collisions at s=8 TeV, recorded by the ATLAS detector at the CERN Large Hadron Collider. The observed distribution of the invariant mass of the three final-state particles, mℓℓγ, is consistent with the Standard Model hypothesis in the investigated mass range of 120-150 GeV. For a Higgs boson with a mass of 125.5 GeV, the observed upper limit at the 95% confidence level is 11 times the Standard Model expectation. Upper limits are set on the cross section times branching ratio of a neutral Higgs boson with mass in the range 120-150 GeV between 0.13 and 0.5 pb for s=8 TeV at 95% confidence level

Measurement of the production of a W boson in association with a charm quark in pp collisions at s√ = 7 TeV with the ATLAS detector

The production of a W boson in association with a single charm quark is studied using 4.6 fb−1 of pp collision data at s√ = 7 TeV collected with the ATLAS detector at the Large Hadron Collider. In events in which a W boson decays to an electron or muon, the charm quark is tagged either by its semileptonic decay to a muon or by the presence of a charmed meson. The integrated and differential cross sections as a function of the pseudorapidity of the lepton from the W-boson decay are measured. Results are compared to the predictions of next-to-leading-order QCD calculations obtained from various parton distribution function parameterisations. The ratio of the strange-to-down sea-quark distributions is determined to be 0.96+0.26−0.30 at Q 2 = 1.9 GeV2, which supports the hypothesis of an SU(3)-symmetric composition of the light-quark sea. Additionally, the cross-section ratio σ(W + + c¯)/σ(W − + c) is compared to the predictions obtained using parton distribution function parameterisations with different assumptions about the s−s¯ quark asymmetry

Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at √s=8 TeV with the ATLAS detector

The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1 fb−1 of proton-proton collision data at s√ = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via t¯ →tχ¯01 or t¯ →bχ¯±1 →bW(∗)χ¯01, where χ¯01 (χ¯±1) denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction of t¯ →tχ¯01. For a branching fraction of 100%, top squark masses in the range 270–645 GeV are excluded for χ¯01 masses below 30 GeV. For a branching fraction of 50% to either t¯ →tχ¯01 or t¯ →bχ¯±1, and assuming the χ¯±1 mass to be twice the χ¯01 mass, top squark masses in the range 250–550 GeV are excluded for χ¯01 masses below 60 GeV

Search for supersymmetry in events with large missing transverse momentum, jets, and at least one tau lepton in 20 fb−1 of √s = 8 TeV proton-proton collision data with the ATLAS detector

A search for supersymmetry (SUSY) in events with large missing transverse momentum, jets, at least one hadronically decaying tau lepton and zero or one additional light leptons (electron/muon), has been performed using 20.3fb−1 of proton-proton collision data at √s = 8 TeV recorded with the ATLAS detector at the Large Hadron Collider. No excess above the Standard Model background expectation is observed in the various signal regions and 95% confidence level upper limits on the visible cross section for new phenomena are set. The results of the analysis are interpreted in several SUSY scenarios, significantly extending previous limits obtained in the same final states. In the framework of minimal gauge-mediated SUSY breaking models, values of the SUSY breaking scale Λ below 63 TeV are excluded, independently of tan β. Exclusion limits are also derived for an mSUGRA/CMSSM model, in both the R-parity-conserving and R-parity-violating case. A further interpretation is presented in a framework of natural gauge mediation, in which the gluino is assumed to be the only light coloured sparticle and gluino masses below 1090 GeV are excluded