Abstract In this article, we will review beam dynamics of a Fixed Field Alternating Gradient Accelerator (FFA). Difference between scaling and nonscaling design, some novel concepts studied recently are explained. Longitudinal dynamics specific to an FFA is introduced. Techniques for modeling of linear and nonlinear dynamics are discussed.
In recent decades, the spectroscopy of singly heavy baryons has made significant progress, with many excited states observed experimentally. Among the various theoretical approaches used to study their properties, the QCD sum rule method has been widely applied. In this paper, we review QCD sum rule studies of singly heavy baryons, with particular emphasis on our systematic investigations of P -wave states over the past ten years using QCD sum rules and light-cone sum rules within the framework of heavy quark effective theory. These studies provide plausible interpretations for many observed excited heavy baryons, including the Λ_c(2595)^+ , Λ_c(2625)^+ , Ξ_c(2790)^0/+ , Ξ_c(2815)^0/+ , Σ_c(2800)^0 , Ξ_c(2882)^0 , Ξ_c(2923)^0 , Ξ_c(2939)^0 , Ξ_c(2965)^0 , Ω_c(3000)^0 , Ω_c(3050)^0 , Ω_c(3066)^0 , Ω_c(3090)^0 , Ω_c(3119)^0 , Λ_b(5912)^0 , Λ_b(5920)^0 , Ξ_b(6087)^0 , Ξ_b(6095)^0/Ξ_b(6100)^- , Σ_b(6097)^± , Ξ_b(6227)^- , Ω_b(6316)^- , Ω_b(6330)^- , Ω_b(6340)^- , and Ω_b(6350)^- . While the absolute masses extracted from QCD sum rules may have sizable systematic uncertainties, the relative mass splittings and qualitative decay patterns are generally more robust and thus provide useful guidance for phenomenological assignments and future experimental searches. We also predict a number of yet-unobserved P -wave singly heavy baryons, many of which are expected to have relatively narrow decay widths and are therefore promising for experimental observation. More broadly, the study of singly heavy baryons is closely related to two fundamental questions: “What is the shortest possible lifetime of an observable particle” and “How can one generally describe approximate (flavor) symmetries”.
Biomolecule analysis plays a vital role in early disease diagnosis, personalized nutrition, food science, and basic biomedical research. Yet, current technologies face fundamental trade-offs between each pair of the parameters including sensitivity, throughput and cost. In this work, a scalable platform for biomolecule sensing was proposed based on amorphous gallium oxide (a-Ga2O3) thin film considering its remarkable deep ultraviolet (UV) response property and unique low-temperature compatibility with large-area electronics. A single-pixel a-Ga2O3 photodetector with a peak responsivity of 0.65 A/W at 255 nm was first employed to identify four basic biomolecules including adenine, guanine, L-phenylalanine, and L-tyrosine. The concentration-dependent photocurrent varied in good agreement with their distinct UV absorbance properties verified by a commercial UV-Vis spectrometer. Further, a 64 × 64 deep UV imaging array was constructed by directly depositing the a-Ga2O3 film onto a commercial amorphous silicon (a-Si) thin-film transistor (TFT) backplane, successfully achieving a high-throughput imaging of the four biomolecules. These results establish a viable strategy for a portable, miniaturized and cost-effective biomolecule sensing circuit with rapid and label-free detection.
