First papers published in our Frontiers special topic

Last year, some colleagues (Lu Guo (郭璐), Denis Lacroix, Cédric Simenel, Nicolas Schunck) and I started organising and co-editing a special topic in the Frontiers in Physics journal on "Advances in Time-dependent Methods for Nuclear Structure and Dynamics".  We hoped to get a fairly broad snapshot of the current active work in the area, and a review of important problems.  I'm pleased to say that the first couple of papers have recently been published:

• Collective Inertial Masses in Nuclear Reactions,  Kai Wen and Takashi Nakatsukasa,  Front. Phys. 8, 16 (2020) describes a problem in going from a fully microscopic picture of nuclei (in which you treat each proton and neutron as an individual entity, and keep track of how they are evolving) to a collective picture (in which you characterise the whole nucleus in terms of a few parameters, such as its position, size, deformation).  One can derive collective equations of motion from the more complicated microscopic picture, thus providing a sure footing, but there is always a difficulty of how to deal with the mass in the kinetic energy term.  This paper discusses a particular method to derive these masses from the underlying microscopic theory, and that the results are consistent in the limit of several test cases, as well as showing interesting results for alpha-alpha scattering.

• Time-dependent Approaches to Open Quantum Systems, Maasaki Tokeida, and Kouichi Hagino, Front. Phys. 8, 8 (2020) discusses the problem of describing a quantum system that interacts with its environment, or a quantum system which can lose particles - an "open quantum system".  The loss, or dissipation, of energy, or of particles, or information can be a complicated (and complex in the mathematical sense, for that matter) thing to describe, and the authors develop and present two methods to describe systems which lose information to the environment, using a time-dependent approach, and show how each can be applied to the nuclear physics case of a heavy-ion collision.

There are several more papers to come, and I'm looking forward to reading them all, and having them as a useful collection of papers for everyone working in the field.  The picture is from the Wen and Nakatsukasa paper, showing snapshots of a calculation of and alpha+alpha reaction