Power counting for three-body decays of a near-threshold state

We propose a new power counting for the effective field theory describing a near-threshold state with unstable constituents, such as the X(3872) meson. In this counting, the momenta of the heavy particles, the pion mass and the excitation energy of the unstable constituent -- the D* in the case of the X -- are treated as small scales, of order Q. The difference, delta, between the excitation energy of the D* and the pion mass is smaller than either by a factor ~20. We therefore assign delta an order Q^2 in our counting. This provides a consistent framework for a double expansion in both delta/m_pi and the ratio of m_pi to the high-energy scales in this system. It ensures that amplitudes have the correct behaviour at the three-body threshold. It allows us to derive, within an effective theory, various results which have previously been obtained using physically-motivated approximations.Comment: 5 pages, 1 figure; more discussion of pion exchange adde

An In-Depth Empirical Investigation of State-of-the-Art Scheduling Approaches for Cloud Computing

Recently, Cloud computing has emerged as one of the widely used platforms to provide compute, storage and analytics services to end-users and organizations on a pay-as-you-use basis, with high agility, availability, scalability, and resiliency. This enables individuals and organizations to have access to a large pool of high processing resources without the need for establishing a high-performance computing (HPC) platform. From the past few years, task scheduling in Cloud computing is reckoned as eminent recourse for researchers. However, task scheduling is considered an NP-hard problem. In this research work, we investigate and empirically compare some of the most prominent state-of-the-art scheduling heuristics in terms of Makespan, Average resource utilization (ARUR), Throughput, and Energy consumption. The comparison is then extended by evaluating the approaches in terms of individual VM level load imbalance. After extensive simulation, the comparative analysis has revealed that Task Aware Scheduling Algorithm (TASA) and Proactive Simulation-based Scheduling and Load Balancing (PSSLB) outperformed as compared to the rest of the approaches and seems to be optimal choice keeping in view the trade-of between the complexities involved and the performance achieved concerning Makespan, Throughput, resource utilization, and Energy consumption

The slings and arrows of communication on nanotechnology

According to numerous surveys the perceived risk of nanotechnology is low and most people feel that the benefits outweigh the risks. This article provides greater insight into risk perception and concludes that the positive attitude to nanotechnology is based not on knowledge but on hope and fascination. The perceived risk is low because of a lack of vivid and frightening images of possible hazards. If news flashes were to link nanotechnology to concrete hazards or actual harm to people, attitudes might suddenly change. Risk communication faces the problem of dealing with a public at large that has little or no knowledge about the technology. As it takes time and extensive additional research to develop appropriate communication strategies and disseminate them to the relevant institutions, this exercise should be started immediately