0000000001318465
AUTHOR
H. Nishioka
Star orbits in metal clusters
A possibility that classical five-point star orbits play a dominant role for shell structures of large metal clusters is investigated quantum mechanically. With a soft Woods-Saxon spherical potential a signature of the five-point star orbit is found in the level densities. Quantum numbers of degenerate levels in the soft Woods-Saxon potential differ by 2 and 5 in radial nodes and angular momenta, respectively. Unlike the experimental observation the peaks in the mass spectrum are not equally spaced as a function of N 1/3 . The self-consistent jellium model does not reproduce the degeneracy associated with the five-point star orbits. It is demonstrated that by covering high-density metal clu…
Odd-even staggering in simple models of metal clusters
The odd-even staggering of free-electron metal clusters is studied using several simple models: Noninter-acting electrons in a rectangular box, triaxial harmonic oscillator, and Huckel model. Finite temperature effects are studied using the Monte Carlo method. All the models show qualitatively similar odd-even staggering. In the ground state the HOMO-LUMO gap is larger than the neighbouring energy gaps. The reduction of the odd-even staggering due to exchange and correlation is studied using the local-spin-density approximation.
3C 279 Event Horizon Telescope imaging
3C 279 is an archetypal blazar with a prominent radio jet that show broadband flux density variability across the entire electromagnetic spectrum. We use an ultra-high angular resolution technique - global Very Long Baseline Interferometry (VLBI) at 1.3mm (230GHz) - to resolve the innermost jet of 3C 279 in order to study its fine-scale morphology close to the jet base where highly variable gamma-ray emission is thought to originate, according to various models. The source was observed during four days in April 2017 with the Event Horizon Telescope (EHT) at 230 GHz, including the phased Atacama Large Millimeter/submillimeter Array (ALMA), at an angular resolution of ~20uarcsec (at a redshif…