July 20th, 2021

лошадь, диаграмма, Фейнман

Настоящее и будущее солнечных нейтрино

The Future of Solar Neutrinos: https://arxiv.org/abs/2107.08613
G. D. Orebi Gann, K. Zuber, D. Bemmerer, A. Serenelli
In this article we review the current state of the field of solar neutrinos, including flavour oscillations, non-standard effects, solar models, cross section measurements, and the broad experimental program thus motivated and enabled. We discuss the historical discoveries that contributed to current knowledge, and define critical open questions to be addressed in the next decade. We discuss the state of the art of standard solar models, including uncertainties and problems related to the solar composition, and review experimental and model solar neutrino fluxes, including future prospects. We review the state of the art of the nuclear reaction data relevant for solar fusion in the proton-proton chain and carbon-nitrogen-oxygen cycle. Finally, we review the current and future experimental program that can address outstanding questions in this field.
лошадь, диаграмма, Фейнман

Ого, как раз пригодится! Измерение продольного распределения заряда в нерелятивистских пучках...

...с помошью когерентного переходного излучения. Как минимум, можно будет тыкать всем задающим вопросы, мол, нафига нерелятивистские задачи и низкие частоты?.. Жаль, с цитированием они мимо меня немножко промазали:(((

Longitudinal charge distribution measurement of non-relativistic ion beams using coherent transition radiation: https://arxiv.org/abs/2107.08689
R. Singh, T. Reichert
Longitudinal charge profile measurements or bunch shape measurements is a challenge for temporally short non-relativistic bunches. The field profile has a larger longitudinal extent compared to the charge profile for such beams. This affects the ability of field sensing devices such as phase pick-ups or wall current monitors to measure charge distribution. Here we evaluate the feasibility for usage of coherent transition and diffraction radiation from non-relativistic beams for bunch shape measurements.

Кстати, обращаю внимание уважаемого mi1kyway :)
лошадь, диаграмма, Фейнман

О квазиклассическом распространении волновых пакетов

Semiclassical propagation of coherent states and wave packets: hidden saddles: https://arxiv.org/abs/2107.08799
Huichao Wang, Steven Tomsovic
Semiclassical methods are extremely important in the subjects of wave packet and coherent state dynamics. Unfortunately, these essentially saddle point approximations are considered nearly impossible to carry out in detail for systems with multiple degrees of freedom due to the difficulties of solving the resulting two-point boundary value problems. However, recent developments have extended the applicability to a broader range of systems and circumstances. The most important advances are first to generate a set of real reference trajectories using appropriately reduced dimensional spaces of initial conditions, and second to feed that set into a Newton-Raphson search scheme to locate the exposed complex saddle trajectories. The arguments for this approach were based mostly on intuition and numerical verification. In this paper, the methods are put on a firmer theoretical foundation and then extended to incorporate saddles hidden from Newton-Raphson searches initiated with real trajectories. This hidden class of saddles is relevant to tunneling-type processes, but a hidden saddle can sometimes contribute just as much as or more than an exposed one.