Results on two-particle angular correlations for charged particles produced in pp collisions at a centerof-mass energy of 13 TeV are presented. The data were taken with the CMS detector at the LHC and correspond to an integrated luminosity of about 270 nb −1 . The correlations are studied over a broad range of pseudorapidity (jηj < 2.4) and over the full azimuth (ϕ) as a function of charged particle multiplicity and transverse momentum (p T ). In high-multiplicity events, a long-range (jΔηj > 2.0), near-side (Δϕ ≈ 0) structure emerges in the two-particle Δη-Δϕ correlation functions. The magnitude of the correlation exhibits a pronounced maximum in the range 1.0 < p T < 2.0 GeV=c and an approximately linear increase with the charged particle multiplicity, with an overall correlation strength similar to that found in earlier pp data at ffiffi ffi s p ¼ 7 TeV. The present measurement extends the study of near-side long-range correlations up to charged particle multiplicities N ch ∼ 180, a region so far unexplored in pp collisions. The observed longrange correlations are compared to those seen in pp, pPb, and PbPb collisions at lower collision energies.

Abstract:The oxidation behavior of International Thermonuclear Experimental Reactor (ITER) reference tungsten grade has been evaluated in dry air in the temperature range 600 800 °C. At 600 °C, the scale remained protective while the integrity of W 18 O 49 layer was kept. Rapid increase in mass gain resulted from mas sive cracking at local areas in the W 18 O 49 layer. Then, a coarse non protective columnar WO 2.92 scale was developed which favoured rapid inward oxygen transport into the alloy. At 700 and 800 °C, growth stres ses in the scale were released through local cracking. At this stage, WO 2.92 became progressively trans formed into WO 3 when the oxygen partial pressure increased across the scale thickness.

Measurements of the top quark-antiquark (tt) spin correlations and the top quark polarization are presented for tt pairs produced in pp collisions at √ s = 8 TeV. The data correspond to an integrated luminosity of 19.5 fb −1 collected with the CMS detector at the LHC. The measurements are performed using events with two oppositely charged leptons (electrons or muons) and two or more jets, where at least one of the jets is identified as originating from a bottom quark. The spin correlations and polarization are measured from the angular distributions of the two selected leptons, both inclusively and differentially, with respect to the invariant mass, rapidity, and transverse momentum of the tt system. The measurements are unfolded to the parton level and found to be in agreement with predictions of the standard model. A search for new physics in the form of anomalous top quark chromo moments is performed. No evidence of new physics is observed, and exclusion limits on the real part of the chromo-magnetic dipole moment and the imaginary part of the chromo-electric dipole moment are evaluated.The central feature of the CMS apparatus is a superconducting solenoid of 6 m internal diameter, providing a magnetic field of 3.8 T. Within the solenoid volume are a silicon pixel and strip tracker, a lead tungstate crystal electromagnetic calorimeter, and a brass and scintillator hadron calorimeter, each composed of a barrel and two endcap sections. Forward calorimeters extend the pseudorapidity coverage provided by the barrel and endcap detectors. Muons are measured in gas-ionization detectors embedded in the steel flux-return yoke outside the solenoid. The first level of the CMS trigger system, composed of custom hardware processors, uses information from the calorimeters and muon detectors to select the most interesting events in a fixed time interval of less than 4 µs. The high-level trigger processor farm further decreases the event rate from around 100 kHz to less than 1 kHz, before data storage. A more detailed description of the CMS detector, together with a definition of the coordinate system used and the relevant kinematic variables, can be found in Ref. [16]. Event samples 3.1 Object definition and event selectionEvents are selected using triggers that require the presence of at least two leptons (electrons or muons) with transverse momentum (p T ) greater than 17 GeV for the highest-p T lepton and 8 GeV for the second-highest p T lepton. The trigger efficiency per lepton, measured relative to the full offline lepton selection detailed in this section using a data sample of Drell-Yan (Z/γ → ) events, is about 98% (96%) for electrons (muons), with variations at the level of several percent depending on the pseudorapidity η and p T of the lepton. 3.2 Signal and background simulation 6 5 Event yields and measurements at the reconstruction level

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