The dynamics of a quantum wave packet of a neutron bouncing under the influence of gravity - Newton's law and the question of extra dimensions of space-time

中子量子波包在引力影响下弹跳的动力学——牛顿定律和时空额外维度问题

• 批准号: 66291586
• 负责人: Professor Dr. Hartmut Abele
• 金额: --
• 依托单位: Atominstitut
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2010-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/66291586?language=en
• 关键词: dynamics; quantum; wave; packet; neutron

The dynamics of a quantum mechanical wave packet bouncing off a hard surface in the gravitational field of the earth combines quantum theory with aspects of Newtonian mechanics at short distances. We propose to realize such a quantum bouncing ball with ultracold neutrons in a system, in which we have measured before the lowest stationary quantum states in the earth’s gravitational field. For the new purpose, a careful measurement of the neutron density distribution above the mirror is necessary, and spatial neutron detectors must be developed. This experiment is sensitive to gravity-like forces at a length scale below 10 μm, where we already place limits. The limits can be significantly improved by studying the dynamics of the wave packets, because Newtonian gravity and hypothetical fifth forces evolve with different phase information. Such forces can be mediated from gauge bosons propagating in a higher dimensional space and this experiment can therefore test speculations on large extra dimensions of submillimeter size of space-time or the origin of the cosmological constant in the universe, where effects are predicted in the interesting range of this experiment and might give a signal in an improved setup.

量子力学波包在地球引力场中从坚硬表面反弹的动力学结合了量子理论和短距离牛顿力学的各个方面。我们建议在一个系统中实现这样一个带有超冷中子的量子弹跳球，在这个系统中，我们在地球引力场中测量了最低定态量子态。为了实现这一新的目标，必须仔细测量反射镜上方的中子密度分布，并研制空间中子探测器。这个实验对10 μ m以下长度尺度的类重力敏感，我们已经对此进行了限制。通过研究波包的动力学，极限可以得到显著的改善，因为牛顿引力和假设的第五种力具有不同的相位信息。这种力可以从在高维空间中传播的规范玻色子中传递出来，因此这个实验可以测试对时空亚毫米尺寸的大额外维度或宇宙学常数起源的猜测，在这个实验的有趣范围内预测效果，并可能在改进的设置中给出信号。