根据申请人最近发表的PRL 115,182001(2015)中所提出实验方案，我们申请使用低压极化3He气体自旋弛豫时间来探测标准模型之外的新物理。高极化率、高密度极化惰性气体3He的研究在过去二三十年内取得了非常快速的进展。一方面，极化3He具有非常广泛的应用价值，例如：基于极化3He的中子极化技术是目前已知最先进的中子极化技术—这也是研究中子散射的中国绵阳研究堆积极开展极化3He研究的根本原因；另一方面，原子核极化的极化惰性气体是基础核物理、粒子物理等研究领域里的重要目标，极化3He原子核是与自旋相关的超越标准模型之外的新物理良好探针。根据我们在PRL文章中的方案，在极化3He极化中子技术的基础上，如果使用一个mbar量级的低压3He容器，测得约1000小时的纵向弛豫时间并精确的消除磁场梯度所造成的影响，可将已有新物理新相互作用的最好探测结果改善大约100倍。

Based on the recent publication of PRL 115,182001(2015), we propose to detect new physics beyond the standard model using the spin relaxations of low pressure polarized 3He gas. Rapid developments have been occurred on producing high polarization and high density polarized 3He gas in the past a few decades. On one hand, polarized 3He gas has many practical applications, for example, neutron polarizing techniques based on polarized 3He gas is the state of art technology to polarize or analyze neutrons. CMRR(China Mianyang Research Reactor) has investigated a lot of effort on studying polarized 3He gas. On the other hand, polarized noble gases are important research objectives for fundamental nuclear physics and particle physics. Polarized 3He gas is an excellent probe to detect spin dependent new physics beyond the standard model. According to the scheme of the PRL paper, based the polarized 3He neutron spin filter techniques, for a ~mbar low pressure 3He cell, if we can obtain ~1000 hours long longitudinal spin relaxation time and remove the magnetic field gradient effect precisely, we can improve the best known results by a factor of ~100.