Proposal of Direct Search for Strongly Bound States of ppbar, npbar Systems with High Intensity and Collective pbar beam

In this letter, we discuss the possibility to look for the direct evidence of the existence of the ppbar and npbar bound states. Measurement of the single \gamma ray from the ppbar and npbar systems at rest can directly confirm whether the X(1860) and X(1835) are the resonances which are strongly coupled to ppbar. In addition to the neutral candidate, a charged resonance $X^-$ is also proposed to be searched for in npbar channel. We find that the data from the Crystal Barrel experiment at LEAR/CERN can be used to confirm the X(1835) observed by BES Collaboration. The possibility of measuring the $\gamma$ spectrum below 100 MeV at the new experiment with cold high intensity \pbar beam at GSI is discussed. These new techniques can be used to probe the structure of the X(1860) and X(1835) in the future.Comment: Accepted by Mod. Phys. Lett.

Study of Scalar Mesons at BES-II

Recent results from BES-II experiment on hadron spectroscopy using \jpsi and $\psi^\prime$ data samples collected in $e^+e^-$ annihilation are presented, including study of the scalar particles in \jpsi radiative and hadronic decays, the observation of X(1810) in $J/\psi \to \gamma \phi \omega$, as well as pair productions of scalars in $\chi_{c0}$ hadronic decays.Comment: Talk on "Hadron spectroscopy at BES" at "From Phi to Psi" Workshop February 27 - March 2, 2006, Novosibirsk, Russi

An Investigation of University Students' Classroom Seating Choices

The classroom is crucial for students, and seating position within the classroom can affect students’ performance. This study conducted a survey to investigate the relationship between seating zones and academic performance among 174 university students in Beijing. The results revealed differences in student performance in terms of seating position in small- and medium-sized traditional classrooms. However, the results did not indicate a similar hierarchy of student performance in terms of seating zones in larger traditional classrooms, horseshoe classrooms, collaboration classrooms, and computer classrooms. Additionally, the results revealed that most students considered the layout of a classroom to affect their performance

Electromagnetic modelling using T-A formulation for high-temperature superconductor (RE)Ba2Cu3Oxhigh field magnets

Second generation (2G) high-temperature superconductor (HTS) (RE)Ba2Cu3Ox(REBCO) shows a great potential in building high field magnets beyond 23.5 T. The electromagnetic modelling is vital for the design of HTS magnet, however, this always suffers the challenge of huge computation for high field magnets with large number of turns. This study presents a novel electromagnetic modelling based on T-A formulation for REBCO magnets with thousands of turns. An equivalent turn method is proposed to reduce the number of turns in calculation, so that the computation cost can be reduced significantly, and meanwhile the key electromagnetic behaviour of HTS magnet can be simulated with enough accuracy. The ramping operation of a fully HTS magnet with 12,000 turns are analysed using both the original T-A model with actual turns and improved T-A model with equivalent turns. The two models show a good agreement on the key electromagnetic behaviours of the magnet: distribution of current density, magnetic fields, screen current induced field and magnetisation loss, so that this improved T-A model using equivalent turns is validated. The T-A modelling of REBCO magnet is a powerful tool for the electromagnetic analysis of industry-scale high field magnets