The new measurement of the muon's anomalous magnetic moment released by the Muon g-2 experiment at Fermilab sets strong constraints on the properties of many new particles. Using an effective field theory approach to the interactions of higher-spin fields, we evaluate the contribution of an electrically neutral and colour singlet spin-3/2 fermion to ${(g-2)}_{\mu }$ and derive the corresponding constraints on its mass and couplings. These constraints are then compared with the ones on spin-1/2 fermions, such as the vector-like leptons that are predicted by various extensions of the Standard Model, the excited leptons which appear in composite models, as well as the charginos and neutralinos of supersymmetric theories. Unlike these new spin-1/2 fermions, the spin-3/2 particles generate only small contributions to the muon anomalous magnetic moment unless the effective new physics scale is very close to the electroweak scale.

费米实验室的 μ 子 g-2 实验释放的 μ 子异常磁矩的新测量对许多新粒子的性质设置了严格的限制。使用有效的场论方法来研究高自旋场的相互作用，我们评估了电中性和彩色单线态自旋 3/2 费米子对${(G-2)}_{\mu }$并导出对其质量和耦合的相应约束。然后将这些约束与自旋 1/2 费米子上的约束进行比较，例如标准模型的各种扩展预测的类矢量轻子、复合模型中出现的激发轻子，以及 charginos 和中性子超对称理论。与这些新的自旋 1/2 费米子不同，自旋 3/2 粒子对 μ 子异常磁矩的贡献很小，除非有效的新物理尺度非常接近电弱尺度。