23,614 research outputs found

    Infrared probe of the anomalous magnetotransport of highly oriented pyrolytic graphite in the extreme quantum limit

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    We present a systematic investigation of the magnetoreflectance of highly oriented pyrolytic graphite in magnetic field B up to 18 T . From these measurements, we report the determination of lifetimes tau associated with the lowest Landau levels in the quantum limit. We find a linear field dependence for inverse lifetime 1/tau(B) of the lowest Landau levels, which is consistent with the hypothesis of a three-dimensional (3D) to 1D crossover in an anisotropic 3D metal in the quantum limit. This enigmatic result uncovers the origin of the anomalous linear in-plane magnetoresistance observed both in bulk graphite and recently in mesoscopic graphite samples

    Metamaterial with polarization and direction insensitive resonant transmission response mimicking electromagnetically induced transparency

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    We report on a planar metamaterial, the resonant transmission frequency of which does not depend on the polarization and angle of incidence of electromagnetic waves. The resonance results from the excitation of high-Q antisymmetric trapped current mode and shows sharp phase dispersion characteristic to Fano-type resonances of the electromagnetically induced transparency phenomenon

    ηc\eta_c mixing effects on charmonium and BB meson decays

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    We include the ηc\eta_c meson into the η\eta-η\eta'-GG mixing formalism constructed in our previous work, where GG represents the pseudoscalar gluball. The mixing angles in this tetramixing matrix are constrained by theoretical and experimental implications from relevant hadronic processes. Especially, the angle between ηc\eta_c and GG is found to be about 1111^\circ from the measured decay widths of the ηc\eta_c meson. The pseudoscalar glueball mass mGm_G, the pseudoscalar densities mqq,ss,ccm_{qq,ss,cc} and the U(1) anomaly matrix elements associated with the mixed states are solved from the anomalous Ward identities. The solution mG1.4m_G\approx 1.4 GeV obtained from the η\eta-η\eta'-GG mixing is confirmed, while mqqm_{qq} grows to above the pion mass, and thus increases perturbative QCD predictions for the branching ratios Br(BηK)Br(B\to\eta'K). We then analyze the ηc\eta_c-mixing effects on charmonium magnetic dipole transitions, and on the Bη()KSB\to\eta^{(\prime)}K_S branching ratios and CP asymmetries, which further improve the consistency between theoretical predictions and data. A predominant observation is that the ηc\eta_c mixing enhances the perturbative QCD predictions for Br(BηK)Br(B\to\eta'K) by 18%, but does not alter those for Br(BηK)Br(B\to\eta K). The puzzle due to the large Br(BηK)Br(B\to\eta'K) data is then resolved.Comment: 12 pages, version to appear in PR

    Orbital symmetry fingerprints for magnetic adatoms in graphene

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    In this paper, we describe the formation of local resonances in graphene in the presence of magnetic adatoms containing localized orbitals of arbitrary symmetry, corresponding to any given angular momentum state. We show that quantum interference effects which are naturally inbuilt in the honeycomb lattice in combination with the specific orbital symmetry of the localized state lead to the formation of fingerprints in differential conductance curves. In the presence of Jahn-Teller distortion effects, which lift the orbital degeneracy of the adatoms, the orbital symmetries can lead to distinctive signatures in the local density of states. We show that those effects allow scanning tunneling probes to characterize adatoms and defects in graphene.Comment: 15 pages, 11 figures. Added discussion about the multi-orbital case and the validity of the single orbital picture. Published versio

    Prior-based Coregistration and Cosegmentation

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    We propose a modular and scalable framework for dense coregistration and cosegmentation with two key characteristics: first, we substitute ground truth data with the semantic map output of a classifier; second, we combine this output with population deformable registration to improve both alignment and segmentation. Our approach deforms all volumes towards consensus, taking into account image similarities and label consistency. Our pipeline can incorporate any classifier and similarity metric. Results on two datasets, containing annotations of challenging brain structures, demonstrate the potential of our method.Comment: The first two authors contributed equall

    Rho primes in analyzing e+e- annihilation, MARK III, LASS and ARGUS data

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    The results of an analysis are presented of some recent data on the reactions e+eπ+ππ+πe^+e^-\to\pi^+\pi^-\pi^+\pi^-, e+eπ+ππ0π0e^+e^-\to\pi^+\pi^-\pi^0\pi^0 with the subtracted ωπ0\omega\pi^0 events, e+eωπ0e^+e^-\to\omega\pi^0, e+eηπ+πe^+e^-\to\eta \pi^+\pi^-, e+eπ+πe^+e^-\to\pi^+\pi^-, Kpπ+πΛK^-p\to\pi^+\pi^-\Lambda, the decays J/ψπ+ππ0J/\psi\to\pi^+\pi^-\pi^0, tauνtauπ+πππ0tau^-\to\nu_tau\pi^+\pi^-\pi^-\pi^0 tauντωπtau^-\to\nu_\tau\omega\pi^-, upon taking into account both the strong energy dependence of the partial widths on energy and the previously neglected mixing of the ρ\rho type resonances. The above effects are shown to exert an essential influence on the specific values of masses and coupling constants of heavy resonances and hence are necessary to be accounted for in establishing their true nature.Comment: 20 pages, ReVTeX, 9 Postscript figures As compared to hep-ph/9607398, new material concerning the analysis of the ARGUS data on the tau decays into four pion hadronic states is adde

    Real-time 3D Tracking of Articulated Tools for Robotic Surgery

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    In robotic surgery, tool tracking is important for providing safe tool-tissue interaction and facilitating surgical skills assessment. Despite recent advances in tool tracking, existing approaches are faced with major difficulties in real-time tracking of articulated tools. Most algorithms are tailored for offline processing with pre-recorded videos. In this paper, we propose a real-time 3D tracking method for articulated tools in robotic surgery. The proposed method is based on the CAD model of the tools as well as robot kinematics to generate online part-based templates for efficient 2D matching and 3D pose estimation. A robust verification approach is incorporated to reject outliers in 2D detections, which is then followed by fusing inliers with robot kinematic readings for 3D pose estimation of the tool. The proposed method has been validated with phantom data, as well as ex vivo and in vivo experiments. The results derived clearly demonstrate the performance advantage of the proposed method when compared to the state-of-the-art.Comment: This paper was presented in MICCAI 2016 conference, and a DOI was linked to the publisher's versio

    Photon assisted tunneling as an origin of the Dynes density of states

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    We show that the effect of a high-temperature environment in current transport through a normal metal-insulator-superconductor tunnel junction can be described by an effective density of states (DOS) in the superconductor. In the limit of a resistive low-ohmic environment, this DOS reduces into the well-known Dynes form. Our theoretical result is supported by experiments in engineered environments. We apply our findings to improve the performance of a single-electron turnstile, a potential candidate for a metrological current source.Comment: 4+3 pages, 4 figures; updated to the published version, includes EPAPS supplementary materia

    The ννγ\nu \nu \gamma Amplitude in an External Homogeneous Electromagnetic Field

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    Neutrino-photon interactions in the presence of an external homogeneous constant electromagnetic field are studied. The ννγ\nu \nu \gamma amplitude is calculated in an electromagnetic field of the general type, when the two field invariants are nonzero.Comment: 7 pages, 1 figur
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