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- Aaltonen, T., et al.
(författare)
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Tevatron Run II combination of the effective leptonic electroweak mixing angle
- 2018
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Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 97:11
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Tidskriftsartikel (refereegranskat)abstract
- Drell-Yan lepton pairs produced in the process p (p) over bar -> l(+)l(-) + X through an intermediate gamma*/Z boson have an asymmetry in their angular distribution related to the spontaneous symmetry breaking of the electroweak force and the associated mixing of its neutral gauge bosons. The CDF and D0 experiments have measured the effective-leptonic electroweak mixing parameter sin(2) theta(lept)(eff) using electron and muon pairs selected from the full Tevatron proton-antiproton data sets collected in 2001-2011, corresponding to 9-10 fb(-1) of integrated luminosity. The combination of these measurements yields the most precise result from hadron colliders, sin(2)theta(lept)(eff) = 0.23148 +/- 0.00033. This result is consistent with, and approaches in precision, the best measurements from electron-positron colliders. The standard model inference of the on-shell electroweak mixing parameter sin(2) theta(W), or equivalently the W-boson mass M-W, using the ZFITTER software package yields sin(2) theta(W) = 0.22324 +/- 0.00033 or equivalently, M-W = 80.367 +/- 0.017 GeV/c(2).
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| 2. |
- Cheng, Q., et al.
(författare)
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Unveiling anneal hardening in dilute Al-doped AlxCoCrFeMnNi (x=0, 0.1) high-entropy alloys
- 2021
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Ingår i: Journal of Materials Science & Technology. - : Elsevier BV. - 1005-0302. ; 91, s. 270-277
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Tidskriftsartikel (refereegranskat)abstract
- Anneal hardening has been one of the approaches to improve mechanical properties of solid solution alloys with the face-centered cubic (FCC) structure, whereby a considerable strengthening can be attained by annealing of cold-worked alloys below the recrystallization temperature (T-rx). Microscopically, this hardening effect has been ascribed to several mechanisms, i.e. solute segregation to defects (dislocation and stacking fault) and short-range chemical ordering, etc. However, none of these mechanisms can well explain the anneal hardening recently observed in phase-pure and coarse-grained FCC-structured high-entropy alloys (HEAs). Here we report the observations, using high-resolution electron channeling contrast imaging and transmission electron microscopy, of profuse and stable dislocation substructures in a cold-rolled CoCrFeMnNi HEA subject to an annealing below T-rx. The dislocation substructures are observed to be thermally stable up to T-rx, which could arise from the chemical complexity of the high-entropy system where certain elemental diffusion retardation occurs. The microstructure feature is markedly different from that of conventional dilute solid solution alloys, in which dislocation substructures gradually vanish by recovery during annealing, leading to a strength drop. Furthermore, dilute addition of 2 at.% Al leads to a reduction in both microhardness and yield strength of the cold-rolled and subsequently annealed (<= 500 degrees C) HEA. This Al induced softening effect, could be associated with the anisotropic formation of dislocation substructure, resulting from enhanced dislocation planar slip due to glide plane softening effect. These findings suggest that the strength of HEAs can be tailored through the anneal hardening effect from dislocation substructure strengthening.
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| 3. |
- Lin, J., et al.
(författare)
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Detection of magnetic circular dichroism in amorphous materials utilizing a single-crystalline overlayer
- 2017
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Ingår i: Physical Review Materials. - 2475-9953. ; 1:7
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Tidskriftsartikel (refereegranskat)abstract
- Electron energy-loss magnetic chiral dichroism (EMCD) is a novel technique that allows magnetic information determination down to the nanoscale. However, constrained by the predefined diffraction geometry in regular EMCD experiments, it has not yet been feasible to obtain EMCD signals from amorphous materials, due to the lack of long-range ordering. Here we propose a protocol for EMCD detection in amorphous materials utilizing a single-crystalline overlayer acting as a two-beam splitter. Phase locking of the EMCD signals is observed and explained by two conceivable scenarios. Both experimental results and theoretical calculations demonstrate significant EMCD signals of amorphous materials.
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