The transverse-momentum (p_{T}) spectra and coalescence parameters B_{2} of (anti)deuterons are measured in p-p collisions at sqrts=13 TeV for the first time in and out of jets. In this measurement, ...the direction of the leading particle with the highest p_{T} in the event (p_{T}^{lead}>5 GeV/c) is used as an approximation for the jet axis. The event is consequently divided into three azimuthal regions, and the jet signal is obtained as the difference between the toward region, that contains jet fragmentation products in addition to the underlying event (UE), and the transverse region, which is dominated by the UE. The coalescence parameter in the jet is found to be approximately a factor of 10 larger than that in the underlying event. This experimental observation is consistent with the coalescence picture and can be attributed to the smaller average phase-space distance between nucleons in the jet cone as compared with the underlying event. The results presented in this Letter are compared to predictions from a simple nucleon coalescence model, where the phase-space distributions of nucleons are generated using pythia8 with the Monash 2013 tuning, and to predictions from a deuteron production model based on ordinary nuclear reactions with parametrized energy-dependent cross sections tuned on data. The latter model is implemented in pythia8.3. Both models reproduce the observed large difference between in-jet and out-of-jet coalescence parameters, although the almost flat trend of the B_{2}^{Jet} is not reproduced by the models, which instead give a decreasing trend.
This Letter presents the observation and measurement of electroweak production of a same-sign W boson pair in association with two jets using 36.1 fb−1 of proton-proton collision data recorded at a ...center-of-mass energy of s=13 TeV by the ATLAS detector at the Large Hadron Collider. The analysis is performed in the detector fiducial phase-space region, defined by the presence of two same-sign leptons, electron or muon, and at least two jets with a large invariant mass and rapidity difference. A total of 122 candidate events are observed for a background expectation of 69±7 events, corresponding to an observed signal significance of 6.5 standard deviations. The measured fiducial signal cross section is σfid=2.89−0.48+0.51(stat)−0.28+0.29(syst) fb.
The condition monitoring of rolling bearings has received much attention in prognostics and health management. Real-time monitoring of the bearings' degradation provides vital information for planned ...maintenance of machinery. However, tracking this degradation is challenging due to the hidden nature of the damages. In this article, the local polynomial phase space warping (LPPSW) algorithm is proposed to monitor the damages of bearings with high accuracy. Damages change the parameters of bearing dynamical systems and warp the trajectory in reconstructed phase space (PS). In the LPPSW algorithm, the kernel function is applied to weigh the local nearest neighbor points in the reconstructed PS. Meanwhile, the quadratic polynomial model is designed to predict the reference PS trajectory. The trajectory error between the reference PS and the damaged PS is then computed by the LPPSW. Finally, the degradation is tracked in real time. Numerical simulations and run-to-failure experiments of bearings are employed to demonstrate the effectiveness of the LPPSW. The experimental results demonstrate that the LPPSW reveals a more obvious degradation trend when compared with PS warping method and commonly used damage indicators. The proposed LPPSW algorithm improves damage monitoring capabilities while boosting the predictive maintenance of bearings.
We present a series of electron holes observed simultaneously on four Magnetospheric Multiscale spacecraft in the plasma sheet boundary layer. The multispacecraft probing shows that the electron ...holes propagated quasi‐parallel to the local magnetic field with velocities of a few thousand kilometers per second with parallel spatial scales of a few kilometers (a few Debye lengths). The simultaneous multispacecraft probing allows analyzing the 3‐D configuration of the electron holes. We estimate the electric field gradients and charge densities associated with the electrons holes. The electric fields are fit to simple 3‐D electron hole models to estimate their perpendicular scales and demonstrate that the electron holes were generally not axially symmetric with respect to the local magnetic field. We emphasize that most of the electron holes had a complicated structure not reproduced by the simple models widely used in single‐spacecraft studies.
Plain Language Summary
We present the first measurement of electron holes (electrostatic solitary waves) by four Magnetospheric Multiscale spacecraft simultaneously. Such observation has allowed us to directly measure the charge density and to address the 3‐D structure of these electron holes both for the first time. The analysis of 3‐D configuration of the electron holes can be valuable for analysis of electron holes observed in space plasmas.
Key Points
Simultaneous observations of electron phase space holes at four MMS spacecraft are presented
The charge density within the electron holes is computed using the electric field measurements at four spacecraft
The three‐dimensional configuration of the electron holes is analyzed, and the perpendicular scales are estimated
Intrinsic electrical and excitonic properties of monolayer transition‐metal dichalcogenides can be revealed on CYTOP fluoropolymer substrates with greatly suppressed unintentional doping and ...dielectric screening. Ambipolar transport behavior is observed in monolayer WS2 by applying solid‐state back gates. The excitonic properties of monolayer MoS2 and WS2 are determined by intricate interplays between the bandgap renormalization, Pauli blocking, and carrier screening against carrier doping.
We present an adaptive algorithm for the optimal phase space sampling in Monte Carlo simulations of 3D Heisenberg spin systems. Based on a golden rule of the Metropolis algorithm which states that an ...acceptance rate of is ideal to efficiently sample the phase space, the algorithm adaptively modifies a cone-based spin update method keeping the acceptance rate close to . We have assessed the efficiency of the adaptive algorithm through four different tests and contrasted its performance with that of other common spin update methods. In systems at low and high temperatures and anisotropies, the adaptive algorithm proved to be the most efficient for magnetization reversal and for the convergence to equilibrium of the thermal averages and the coercivity in hysteresis calculations. Thus, the adaptive algorithm can be used to significantly reduce the computational cost in Monte Carlo simulations of 3D Heisenberg spin systems.
The well-known transport of intensity equation (TIE) allows the phase of a coherent field to be retrieved non-interferometrically given positive defined intensity measurements and appropriate ...boundary conditions. However, in many cases like the optical microscopy, the imaging systems often involve extended and polychromatic sources for which the effect of the partial coherence is not negligible. In this work, we present a phase-space formulation for the TIE for analyzing phase retrieval under partially coherent illumination. The conventional TIE is reformulated in the joint space-spatial frequency domain using Wigner distribution functions. The phase-space formulation clarifies the physical meaning of the phase of partially coherent fields, and enables explicit account of partial coherence effects on phase retrieval. The correspondence between the Wigner distribution function and the light field in geometric optics limit further enables TIE to become a simple yet effective approach to realize high-resolution light field imaging for slowly varying phase specimens, in a purely computational way.
•The conventional TIE is reformulated in the phase-space using Wigner distribution functions.•The phase-space formulation clarifies the physical meaning of the phase of partially coherent fields.•The phase-space representation enables explicit account of partial coherence effects on phase retrieval.•High-resolution light field can be realized in a purely computational way.
This Letter presents a normalized differential cross-section measurement in a fiducial phase-space region where interference effects between top-quark pair production and associated production of a ...single top quark with a W boson and a b-quark are significant. Events with exactly two leptons (ee, μμ, or eμ) and two b-tagged jets that satisfy a multiparticle invariant mass requirement are selected from 36.1 fb−1 of proton-proton collision data taken at s=13 TeV with the ATLAS detector at the LHC in 2015 and 2016. The results are compared with predictions from simulations using various strategies for the interference. The standard prescriptions for interference modeling are significantly different from each other but are within 2σ of the data. State-of-the-art predictions that naturally incorporate interference effects provide the best description of the data in the measured region of phase space most sensitive to these effects. These results provide an important constraint on interference models and will guide future model development and tuning.
The paper is devoted to the study of cardiac rhythm variability (CRV) using the phase and extended phase spaces of instantaneous cardiac rhythm (ICR) obtained from the Holter monitoring (HM) data. In ...order to construct these spaces, a software package is developed and implemented. With specific references, the fractality of the ICR phase space is demonstrated. The fractal phase space volume and fractal entropy definitions of ICR are given. The paper justifies their availability for CRV quantitative assessment.
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