在Nuclotron/NICA、HIAF及更高能装置中对极化氘核的新探索
Fresh Look at Polarized Deuterons at the Nuclotron/NICA \& HIAF and Beyond
AI总结：
该研究针对Nuclotron/NICA、HIAF等装置，开发了JEDI的傅里叶分析技术，解析了张量极化退相干，证实氘核极化寿命可达数小时，为自旋结构、宇称及T破坏研究提供可行方法。
AI中文摘要：
氘核作为自旋为1的粒子，极化后可提供丰富的张量可观测量。在未来对撞机中，利用极化氘核开展自旋物理研究的核心是探寻张量不对称性，这要求储存环或氘靶中频繁进行张量极化翻转。本文聚焦JEDI开发的连续射频驱动自旋翻转下水平极化振荡的傅里叶分析技术，该技术产生的带时间戳的储存粒子振荡螺旋度，为核子/原子核自旋结构研究及宇称破坏搜寻提供了途径。同时，该技术可生成一整套张量自旋不对称性，包括超出标准模型的T破坏搜寻所需的非对角张量自旋不对称性。关键要素是长极化寿命，本文首次对连续射频自旋翻转下张量极化的退相干进行了解析处理。主要结论是，在低能和中能加速器中，氘核极化寿命可达数小时量级，使该振荡极化方法在Nuclotron/NICA和HIAF上具备可行性。此外，本文探讨了内部靶中氘核相互作用截面的平顶自旋-张量二向色性的效用，其可作为张量极化的监测手段，同时二向色性效应可用于测量自旋进动频率，并作为共磁计同步对撞机中对撞束团的自旋相位。
英文摘要：
Being a spin-1 particle, the deuteron, when polarized, offers access to a wide range of interesting tensor observables. A quest for tensor asymmetries is at the heart of the spin physics with polarized deuterons at future colliders, and calls for frequent tensor polarization flips in storage rings or in deuterium targets. Here we focus on the JEDI developed technique of the Fourier analysis of the horizontal polarization oscillations under continuous radiofrequency driven spin flips. The so generated time-stamped oscillating helicity of stored particles paves the way to the nucleon/nucleus spin structure studies and to the search for the parity violation. Simultaneously a whole set of tensor spin asymmetries, including the off-diagonal ones needed for searches for the T-violation beyond the Standard Model, will be produced. A crucial ingredient is a long polarization lifetime, and we report the first analytic treatment of decoherence of the tensor polarization under continuous radiofrequency spin flips. Our principal conclusion is that at low- and intermediate-energy accelerators the deuteron polarization lifetime could be in the ballpark of several hours, making the oscillating polarization approach viable at Nuclotron/NICA and HIAF. We comment on a utility of the flattop spin-tensor dichroism via oscillations in the cross section of interaction of deuterons in the internal target as a monitor of the tensor polarization. Simultaneously, the dichroism effect can be used for measuring the spin precession frequences and as a comagnetometer to synchronize spin phases of colliding bunches in a collider.
