The standard model of particle physics accurately describes all particle physics measurements made so far in the laboratory. However, it is unable to answer many questions that arise from cosmological observations, such as the nature of dark matter and why matter dominates over antimatter throughout the Universe. Theories that contain particles and interactions beyond the standard model, such as models that incorporate supersymmetry, may explain these phenomena. Such particles appear in the vacuum and interact with common particles to modify their properties. For example, the existence of very massive particles whose interactions violate time-reversal symmetry, which could explain the cosmological matter–antimatter asymmetry, can give rise to an electric dipole moment along the spin axis of the electron. No electric dipole moments of fundamental particles have been observed. However, dipole moments only slightly smaller than the current experimental bounds have been predicted to arise from particles more massive than any known to exist. Here we present an improved experimental limit on the electric dipole moment of the electron, obtained by measuring the electron spin precession in a superposition of quantum states of electrons subjected to a huge intramolecular electric field. The sensitivity of our measurement is more than one order of magnitude better than any previous measurement. This result implies that a broad class of conjectured particles, if they exist and time-reversal symmetry is maximally violated, have masses that greatly exceed what can be measured directly at the Large Hadron Collider.An experimental measurement of the electric dipole moment of the electron with sensitivity an order of magnitude better than previous studies increases the accessible mass range of fundamental particles by a factor of three.

中文翻译：

---

改进了对电子电偶极矩的限制

粒子物理学的标准模型准确地描述了迄今为止在实验室中进行的所有粒子物理学测量。然而，它无法回答宇宙学观测中出现的许多问题，例如暗物质的性质以及为什么物质在整个宇宙中比反物质占主导地位。包含超出标准模型的粒子和相互作用的理论，例如包含超对称性的模型，可以解释这些现象。这些粒子出现在真空中并与普通粒子相互作用以改变它们的特性。例如，相互作用违反时间反演对称性的超大质量粒子的存在可以解释宇宙学物质 - 反物质的不对称性，可以产生沿电子自旋轴的电偶极矩。没有观察到基本粒子的电偶极矩。然而，据预测，偶极矩仅略小于当前的实验界限，是由比已知存在的任何粒子都大的粒子产生的。在这里，我们提出了对电子电偶极矩的改进实验限制，该限制是通过测量受到巨大分子内电场的电子量子态叠加中的电子自旋进动而获得的。我们测量的灵敏度比之前的任何测量都要好一个数量级以上。这一结果意味着，如果存在一大类推测粒子，并且时间反转对称性被最大程度地破坏，则其质量将大大超过大型强子对撞机可以直接测量的质量。