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The three-dimensional structure of nucleons (protons and neutrons) is embedded in so-called generalized parton distributions, which are accessible from deeply virtual Compton scattering. In this process, a high energy electron is scattered off a nucleon by exchanging a virtual photon. Then, a highly-energetic real photon is emitted from one of the quarks inside the nucleon, which carries information on the quark's transverse position and longitudinal momentum. By measuring the cross-section of deeply virtual Compton scattering, Compton form factors related to the generalized parton distributions can be extracted. Here, we report the observation of unpolarized deeply virtual Compton scattering off a deuterium target. From the measured photon-electroproduction cross-sections, we have extracted the cross-section of a quasi-free neutron and a coherent deuteron. Due to the approximate isospin symmetry of quantum chromodynamics, we can determine the contributions from the different quark flavours to the helicity-conserved Compton form factors by combining our measurements with previous ones probing the proton's internal structure. These results advance our understanding of the description of the nucleon structure, which is important to solve the proton spin puzzle.

Due to a resource-constrained environment, network compression has become an important part of deep neural networks research. In this paper, we propose a new compression method, \textit{Inter-Layer Weight Prediction} (ILWP) and quantization method which quantize the predicted residuals between the weights in all convolution layers based on an inter-frame prediction method in conventional video coding schemes. Furthermore, we found a phenomenon \textit{Smoothly Varying Weight Hypothesis} (SVWH) which is that the weights in adjacent convolution layers share strong similarity in shapes and values, i.e., the weights tend to vary smoothly along with the layers. Based on SVWH, we propose a second ILWP and quantization method which quantize the predicted residuals between the weights in adjacent convolution layers. Since the predicted weight residuals tend to follow Laplace distributions with very low variance, the weight quantization can more effectively be applied, thus producing more zero weights and enhancing the weight compression ratio. In addition, we propose a new \textit{inter-layer loss} for eliminating non-texture bits, which enabled us to more effectively store only texture bits. That is, the proposed loss regularizes the weights such that the collocated weights between the adjacent two layers have the same values. Finally, we propose an ILWP with an inter-layer loss and quantization method. Our comprehensive experiments show that the proposed method achieves a much higher weight compression rate at the same accuracy level compared with the previous quantization-based compression methods in deep neural networks., Comment: 12 pages, 7 figures

We predict a geometric quantum phase shift of a moving electric dipole in the presence of an external magnetic field at a distance. On the basis of the Lorentz-covariant field interaction approach, we show that a geometric phase appears under the condition that the dipole is moving in the field-free region, which is distinct from the topological He-McKellar-Wilkens phase generated by a direct overlap of the dipole and the field. We discuss the experimental feasibility of detecting this phase with atomic interferometry and argue that detection of this phase would result in a deeper understanding of the locality in quantum electromagnetic interaction., Comment: 5 pages, 2 figures

We report the first longitudinal/transverse separation of the deeply virtual exclusive $\pi^0$ electroproduction cross section off the neutron and coherent deuteron. The corresponding four structure functions $d\sigma_L/dt$, $d\sigma_T/dt$, $d\sigma_{LT}/dt$ and $d\sigma_{TT}/dt$ are extracted as a function of the momentum transfer to the recoil system at $Q^2$=1.75 GeV$^2$ and $x_B$=0.36. The $ed \to ed\pi^0$ cross sections are found compatible with the small values expected from theoretical models. The $en \to en\pi^0$ cross sections show a dominance from the response to transversely polarized photons, and are in good agreement with calculations based on the transversity GPDs of the nucleon. By combining these results with previous measurements of $\pi^0$ electroproduction off the proton, we present a flavor decomposition of the $u$ and $d$ quark contributions to the cross section., Comment: 6 pages, 6 figures, Submitted to Phys. Rev. Lett

We investigate the measurement-induced dephasing of a qubit coupled with a single-mode cavity in the vacuum limit. Dephasing of the qubit state takes place through the ntanglement of the qubit and the single probe photon sent to the cavity, while the cavity mode never occupies a photon. We find that the qubit state is dephased even if the cavity is always in the vacuum state. This dephasing is caused purely by the interaction between the qubit and the vacuum field. We also show that this vacuum-fluctuation-induced dephasing takes place much faster than the spontaneous decay of the qubit excited state, and therefore our prediction is observable in a real experiment., Comment: 6pages, 5 figures

We address the ultimate charge detection scheme with a quantum point contact. It is shown that a superposed input state is necessary to exploit the full sensitivity of a quantum point contact detector. The coherence of the input state provides an improvement in charge sensitivity, and this improvement is a result of the fundamental property of the scattering matrix. Further, a quantum-limited (maximally efficient) detection is possible by controlling the interference between the two output waves. Our scheme provides the ultimate sensitivity and efficiency of charge detection with a generic quantum point contact., Comment: 11 pages, 3 figures

We present a scheme for tuning two quantum point contacts as a quantum-limited charge detector. Based on the scattering matrix approach, we analyze a general condition of quantum-limited detection with a single-channel quantum detector possessing time-reversal symmetry. From this analysis we find that quantum-limited detection can be easily realized with two quantum point contacts connected in series, which is not possible if only a single quantum point contact is used. We also discuss the sensitivity enhancement due to multiple reflections of the two point contacts., Comment: 9 pages, 2 figures

The purpose of this study was to develop a Framework for Performance Assessment in Science Education (F-PASE). Science educators in the past have paid more attention to science curriculum and teaching strategies than assessment. In recent years attention has turned toward performance assessment which addresses the concerns of science curriculum and instruction and which is consistent with goals of science education at various levels of interests. Science educators are trying to do performance assessment, yet they don't have a highly qualified framework in terms of science educational objectives for the future and advantages of performance assessment. The paper has developed a framework for performance assessment in science education, which may be useful for science teachers to understand and assess their students' abilities. Seven domains, covering students' various abilities, are the important objectives of science performance assessment and can be grouped into three categories: General, Science specific, and Intermediate abilities. A F-PASE, with three dimensional solid figured structure, was developed and illustrated as the configuration of a corn. F-PASE is useful for science teachers to develop and select a science performance assessment as well as have a more advanced understanding of their students' abilities. It is a creative and novel assessment framework in terms of a structure, a configuration, functions and meanings. It also suggests a new vision of an assessment framework in science education. (Contains 16 references.) (Author/CCM)

The abundances of D, He-3, He-4, and Li-7, are presently recalculated within the framework of primordial nucleosynthesis in the standard hot big band model, in order to estimate the primordial abundances of the light elements. A comparison between theory and experiment demonstrates the consistency of standard model predictions; the baryon density parameter is constrained on the basis of a nucleon-to-photon ratio of 2.8-4.0. These bounds imply that the bulk of the baryons in the universe are dark, requiring that the universe be dominated by nonbaryonic matter.

Nucleon-nucleon, axion bremsstrahlung is the primary mechanism for axion emission from the nascent neutron star associated with SN 1987A, and the rate for this process has been calculated in the one pion exchange approximation (OPE). The axion mass limit which follows from SN 1987A, m sub a less than or approx equal to 10 to the -3 eV, is the most stringent astrophysical bound, and has received much scrutiny. It has been suggested that by using OPE to calculate the cross section for the analog process, pp yields pp + pi sup o, and comparing the result of the experimental data one can test the validity of this approximation, and further, that such a comparison indicates that OPE leads to a value for this cross section which is a factor of 30 to 40 too large. If true, this would suggest that the axion mass limit should be revised upward by a factor of approximately 6. The cross section for pp yields pp + pi sup o using OPE is carefully evaluated, and excellent agreement found (to better than a factor of 2) with the experimental data.