Compressive deformation and failure of CrAlN/Si3N4 nanocomposite coatings

The deformation and failure mechanisms of CrAlN/Si3N4 coatings containing grains a few nanometres in size have been compared with those of conventional CrN-based coatings. It is shown that the addition of amorphous Si3N4 phase increased the yield stress and hardness of the coating material, but did not change their ratio. This is consistent with theoretical predictions using existing models. However, cracking in conventional CrN-based coatings was catastrophic, whereas that in the fine-grained CrAlN/Si3N4 structure was much more benign, suggesting that the improved performance of these materials is associated with their fracture behaviours.This research was funded by A*STAR, Singapore and the Engineering and Physical Sciences Research Council (EPSRC) and Rolls-Royce Strategic Partnership “Structural Metallic Systems for Advanced Gas Turbine Applications” (EP/H500375/1).This is the accepted version of an article published in Applied Physics Letters. The final version is available online at http://scitation.aip.org/content/aip/journal/apl/104/8/10.1063/1.4867017. © 2014 AIP Publishing LL

Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

Observation of a ppb mass threshoud enhancement in \psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) decay

The decay channel $\psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p})$ is studied using a sample of $1.06\times 10^8$ $\psi^\prime$ events collected by the BESIII experiment at BEPCII. A strong enhancement at threshold is observed in the $p\bar{p}$ invariant mass spectrum. The enhancement can be fit with an $S$-wave Breit-Wigner resonance function with a resulting peak mass of $M=1861^{+6}_{-13} {\rm (stat)}^{+7}_{-26} {\rm (syst)} {\rm MeV/}c^2$ and a narrow width that is $\Gamma<38 {\rm MeV/}c^2$ at the 90% confidence level. These results are consistent with published BESII results. These mass and width values do not match with those of any known meson resonance.Comment: 5 pages, 3 figures, submitted to Chinese Physics

AlN/CrN multilayer structures with increased thermal stability

CrAlYN nanolayered coatings of greatly enhanced thermal stability have been developed by doping with levels of Y up to 9 at.%. This prevented the complete dissolution of the layered structure after annealing at 1100 °C in Ar for 1 h, commonly observed in coatings with little or no Y content, although the bilayer period increased from ~ 5 nm to ~ 10 nm. The improved thermal stability is attributed to the formation of a continuous YN layer between the CrN and AlN layers, reducing the rate of interdiffusion

Improved measurement of the reactor antineutrino flux and spectrum at Daya Bay

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Experimental studies of e + e -→ some charmless processes containing K S0 at √s = 3.773 and 3.65 GeV

We measure the observed cross sections for the charmless processes e + e -→K S0 K - K - K + π ++ c.c., K S0 K - π + η+c.c., K S0 K - π + π + π - η+c.c., K S0 K - K - K + π + η+c.c., K S0 K - K - K + π + π 0+c.c., K S0 K - ρ ++c.c. and K S0 K - π + ρ 0+c.c. We also extract upper limits on the branching fractions for ψ(3770) decays into these final states at 90% C.L. Analyzed data samples correspond to 17.3 pb-1 and 6.5 pb-1 integrated luminosities registered, respectively, at √s = 3.773 and 3.65 GeV, with the BES-II detector at the BEPC collider. © 2009 Springer-Verlag / Società Italiana di Fisica.published_or_final_versionSpringer Open Choice, 21 Feb 201

Measurement of the matrix element for the decay η′→ηπ +π -

The Dalitz plot of η⊃′→ηπ⊃+π⊃- decay is studied using (225.2±2.8)×106 J/ψ events collected with the BESIII detector at the BEPCII e⊃+e⊃- collider. With the largest sample of η⊃′ decays to date, the parameters of the Dalitz plot are determined in a generalized and a linear representation. Also, the branching fraction of J/ψ→γη⊃′ is determined to be (4.84±0.03±0.24)×10⊃-3, where the first error is statistical and the second systematic. © 2011 American Physical Society.published_or_final_versio

Determination of the number of J/ψ events with J/ψ → inclusive decays

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Search for a Light Sterile Neutrino at Daya Bay

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