Although spirometric results indicate normal lung function, the mean VDI in patients (5.1) found in this study is well above the VDI in healthy subjects (1.6) reported in the literature. A single CPT session induces disparate changes in the distribution and extent of ventilation defects.
We report results of a new technique to measure the electric dipole moment of 129 Xe with 3 He comagnetometry. Both species are polarized using spin-exchange optical pumping, transferred to a measurement cell, and transported into a magnetically shielded room, where SQUID magnetometers detect free precession in applied electric and magnetic fields. The result from a one week measurement campaign in 2017 and a 2.5 week campaign in 2018, combined with detailed study of systematic effects, is dA( 129 Xe) = (1.4 ± 6.6stat ± 2.0syst) × 10 −28 e cm. This corresponds to an upper limit of |dA( 129 Xe)| < 1.4 × 10 −27 e cm (95% CL), a factor of five more sensitive than the limit set in 2001.Searches for permanent electric dipole moments (EDMs) are a powerful way to investigate beyondstandard-model (BSM) physics. An EDM is a charge asymmetry along the total angular momentum axis of a particle or system and is odd under both parity reversal (P) and time reversal (T). Assuming CPT conservation (C is charge conjugation), an EDM is a direct signal of CP violation (CPV), a condition required to generate the observed baryon asymmetry of the universe [1]. The Standard Model incorporates CPV through the phase in the CKM matrix and the QCD parameterθ. However, the Standard Model alone is insufficient to explain the size of the baryon asymmetry [2]. BSM scenarios that generate the observed baryon asymmetry [3] generally also provide for EDMs larger than the SM estimate, which for 129 Xe is |d A ( 129 Xe) SM | ≈ 5 × 10 −35 e cm [4].EDM measurements have provided constraints on how BSM CPV can enter low-energy physics [4]. Diamagnetic systems such as 129 Xe and 199 Hg are particularly sensitive to CPV nucleon-nucleon interactions that induce a nuclear Schiff moment and CPV semileptonic couplings [7]. While the most precise atomic EDM measurement is from 199 Hg [8], there are theoretical challenges to constraining hadronic CPV parameters from 199 Hg alone, and improved sensitivity to the 129 Xe EDM would tighten these constraints [7,9]. Additionally, recent work has shown that contributions from light-axion-induced CPV are significantly stronger for 129 Xe than for 199
The performance characteristics of magnetic nanoparticles toward application, e.g., in medicine and imaging or as sensors, are directly determined by their magnetization relaxation and total magnetic moment. In the commonly assumed picture, nanoparticles have a constant overall magnetic moment originating from the magnetization of the single-domain particle core surrounded by a surface region hosting spin disorder. In contrast, this work demonstrates the significant increase of the magnetic moment of ferrite nanoparticles with an applied magnetic field. At low magnetic field, the homogeneously magnetized particle core initially coincides in size with the structurally coherent grain of 12.8(2) nm diameter, indicating a strong coupling between magnetic and structural disorder. Applied magnetic fields gradually polarize the uncorrelated, disordered surface spins, resulting in a magnetic volume more than 20% larger than the structurally coherent core. The intraparticle magnetic disorder energy increases sharply toward the defect-rich surface as established by the field dependence of the magnetization distribution. In consequence, these findings illustrate how the nanoparticle magnetization overcomes structural surface disorder. This new concept of intraparticle magnetization is deployable to other magnetic nanoparticle systems, where the in-depth knowledge of spin disorder and associated magnetic anisotropies are decisive for a rational nanomaterials design.
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