We consider a non-supersymmetric $E_6$ Grand Unified Theory (GUT) with intermediate trinification symmetry $SU{(3)}_C\times SU{(3)}_L\times SU{(3)}_R\times D$ (D denoted as D-parity for discrete left-right symmetry) and study the effect of one-loop threshold corrections arising due to every class of superheavy particles (scalars, fermions and vectors). It is observed that, the intermediate mass scale $M_I$ and ${\sin }^2{\theta }_W$ remain unaffected by GUT threshold contributions. The threshold modified unification mass scale $M_U$ is in excellent agreement with the present experimental proton decay constraint. The novel feature of the model is that GUT threshold uncertainty of $M_U$ is found to be controlled by superheavy scalars only, leading to a very predictive scenario for proton decay, which can be verifiable within the foreseeable experiments.

我们认为是非超对称 ${Ë}_6$ 具有中间三等分对称性的大统一理论（GUT） $\mathrm{小号}ü{（3）}_C\times \mathrm{小号}ü{（3）}_{\mathrm{大号}}\times \mathrm{小号}ü{（3）}_{\mathrm{[R}}\times d$（对于离散的左右对称性，D表示为D奇偶性），并研究由于每类超重粒子（标量，费米子和向量）引起的单循环阈值校正的效果。据观察，中等质量规模${\mathrm{中号}}_{\mathrm{一世}}$ 和 ${\mathrm{罪}}^2{\theta }_{\mathrm{w\; ^}}$不受GUT阈值贡献的影响。门槛修正统一量表${\mathrm{中号}}_{ü}$与目前的实验质子衰变约束非常吻合。该模型的新颖之处在于GUT阈值不确定性${\mathrm{中号}}_{ü}$ 被发现仅受超重标量控制，导致质子衰减的非常可预测的情况，这可以在可预见的实验中得到验证。