Post LSND results, sterile neutrinos have drawn attention and motivated the high energy physics, astronomy and cosmology to probe physics beyond the standard model considering minimal 3+1 (3 active and 1 sterile) to 3+N neutrino schemes. The analytical equations for neutrino conversion probabilities are developed in this work for 3+1 neutrino scheme. Here, we have tried to explore the possible signals of T and CPT violations with four flavor neutrino scheme at neutrino factory. Values of sterile parameters considered in this analysis are taken from two different types of neutrino experiments viz. long baseline experiments and reactor+atmospheric experiments. In this work golden and discovery channels are selected for the investigation of T violation. While observing T violation we stipulate that neutrino factory working at 50 GeV energy have the potential to observe the T violation signatures for the considered range of baselines(3000 km-7500 km). The ability of neutrino factory for constraining CPT violation is enhanced with increase in energy for normal neutrino mass hierarchy(NH). Neutrino factory with the exposure time of 500 kt-yr will be able to capture CPT violation with $ δc_{31}\geq 3.6\times10^{-23} $ GeV at 3$ σ$ level for NH and for IH with $ δc_{31}\geq 4\times10^{-23} $ GeV at 3$ σ$ level.
最近，巴克桑无菌跃迁实验（BEST）的结果证实了镓异常--在SAGE和GALLEX校准时缺乏电子中微子$ν_e$--统计显著性超过5 $\,σ$。这一结果与镓异常的解释是一致的，即电子中微子振荡成无菌中微子，$ν_s$。在这个解释范围内，BEST实验本身在中微子领域所有先前的异常结果中为不育中微子提供了最强有力的证据。我们结合镓实验的结果与搜索无菌中微子在反应堆反中微子实验（假设CPT守恒的$3+1$中微子部门）。虽然“镓”在模型参数空间中的最佳拟合点（无菌中微子质量平方$m_{ν_s}^2\approx 1.25\,$ eV $^2$，无菌电子中微子混合$\sin^22θ\approx 0.34$）被排除在这些搜索之外，但部分最受欢迎的2 $\,σ$区域与$m^2_{ν_s}>5\,$ eV $^2$是一致的。值得注意的是，NEUTRINO-4实验异常结果所宣扬的区域与BEST实验的区域重叠：联合分析的最佳拟合点是$\sin^22θ\approx 0.38$、$m_{ν_s}^2\approx7.3\,$ eV $^2$，有利区域将由KATRIN实验探索。对BEST结果的无菌中微子解释不仅意味着粒子物理学标准模型的扩展，而且意味着对标准宇宙模型和太阳模型的重大修改，或者对抑制早期宇宙和太阳中无菌中微子产生所需的无菌扇区进行特定修改。
