The possible members of the 51S05^1S_0 meson nonet

The strong decays of the $5^1S_0$ $q\bar{q}$ states are evaluated in the $^3P_0$ model with two types of space wave functions. Comparing the model expectations with the experimental data for the $\pi(2360)$, $\eta(2320)$, $X(2370)$, and $X(2500)$, we suggest that the $\pi(2360)$, $\eta(2320)$, and $X(2500)$ can be assigned as the members of the $5^1S_0$ meson nonet, while the $5^1S_0$ assignment for the $X(2370)$ is not favored by its width. The $5^1S_0$ kaon is predicted to have a mass of about 2418 MeV and a width of about 163 MeV or 225 MeV.Comment: 10 pages, 5 figures, version accepted by Eur. Phys. J.

Towards the Implementation and Evaluation of Semi-Partitioned Multi-Core Scheduling

Recent theoretical studies have shown that partitioning-based scheduling has better real-time performance than other scheduling paradigms like global scheduling on multi-cores. Especially, a class of partitioning-based scheduling algorithms (called semi-partitioned scheduling), which allow to split a small number of tasks among different cores, offer very high resource utilization, and appear to be a promising solution for scheduling real-time systems on multi-cores. The major concern about the semi-partitioned scheduling is that due to the task splitting, some tasks will migrate from one core to another at run time, and might incur higher context switch overhead than partitioned scheduling. So one would suspect whether the extra overhead caused by task splitting would counteract the theoretical performance gain of semi-partitioned scheduling. In this work, we implement a semi-partitioned scheduler in the Linux operating system, and run experiments on a Intel Core-i7 4-cores machine to measure the real overhead in both partitioned scheduling and semi-partitioned scheduling. Then we integrate the obtained overhead into the state-of-the-art partitioned scheduling and semi-partitioned scheduling algorithms, and conduct empirical comparison of their real-time performance. Our results show that the extra overhead caused by task splitting in semi-partitioned scheduling is very low, and its effect on the system schedulability is very small. Semi-partitioned scheduling indeed outperforms partitioned scheduling in realistic systems

Canonical interpretation of the X(4140)X(4140) state within the 3P0^3P_0 model

Recently, the LHCb Collaboration has confirmed the state $X(4140)$, with a mass $M=4146.5\pm 4.5^{+4.6}_{-2.8}$~MeV, and a much larger width $\Gamma=83\pm21^{+21}_{-14}$~MeV than the previous experimental measurements, which has confused the understanding of its nature. We will investigate the possibility of the $\chi_{c1}(3P)$ interpretation for the $X(4140)$, considering the mass spectra predicted in the quark model, and the strong decay properties within the $^3P_0$ model. We also predict the strong decay properties of the charmonium states $\chi_{c0}(3P)$ and $\chi_{c2}(3P)$. Our results show that the $X(4140)$ state with the small width given in PDG can be explained as the charmonium state $\chi_{c1}(3P)$ in the $^3P_0$ model, and high precision measurement of the width of the $X(4140)$ is crucial to understand its nature.Comment: 9 pages, 3 figures, the version to be published in EPJ

Utilization-Based Scheduling of Flexible Mixed-Criticality Real-Time Tasks

Mixed-criticality models are an emerging paradigm for the design of real-time systems because of their significantly improved resource efficiency. However, formal mixed-criticality models have traditionally been characterized by two impractical assumptions: once \textit{any} high-criticality task overruns, \textit{all} low-criticality tasks are suspended and \textit{all other} high-criticality tasks are assumed to exhibit high-criticality behaviors at the same time. In this paper, we propose a more realistic mixed-criticality model, called the flexible mixed-criticality (FMC) model, in which these two issues are addressed in a combined manner. In this new model, only the overrun task itself is assumed to exhibit high-criticality behavior, while other high-criticality tasks remain in the same mode as before. The guaranteed service levels of low-criticality tasks are gracefully degraded with the overruns of high-criticality tasks. We derive a utilization-based technique to analyze the schedulability of this new mixed-criticality model under EDF-VD scheduling. During runtime, the proposed test condition serves an important criterion for dynamic service level tuning, by means of which the maximum available execution budget for low-criticality tasks can be directly determined with minimal overhead while guaranteeing mixed-criticality schedulability. Experiments demonstrate the effectiveness of the FMC scheme compared with state-of-the-art techniques.Comment: This paper has been submitted to IEEE Transaction on Computers (TC) on Sept-09th-201

The ϕ(2170)\phi(2170) production in the process γp→ηϕp\gamma p\to \eta \phi p

We have studied the $\gamma p\to \eta \phi p$ reaction within the effective Lagrangian approach, and our results show that there may be a peak, at least a bump structure around 2180 MeV associated to the resonance $\phi(2170)$ in the $\eta\phi$ mass distribution. We suggest to search for the resonance $\phi(2170)$ in this reaction, which would be helpful to shed light on its nature.Comment: 4 pages, 2 figures, contribution to 18th International Conference on Hadron Spectroscopy and Structure (HADRON 2019