Confronting spin-3/2 and other new fermions with the muon g-2 measurement

Criado, Juan C.; Djouadi, Abdelhak; Koivunen, Niko; Müürsepp, Kristjan; Raidal, Martti; Veermäe, Hardi

Abstract

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) 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.

Citation

Criado, J. C., Djouadi, A., Koivunen, N., Müürsepp, K., Raidal, M., & Veermäe, H. (2021). Confronting spin-3/2 and other new fermions with the muon g-2 measurement. Physics Letters B, 820, https://doi.org/10.1016/j.physletb.2021.136491

• Journal Article Type: Article
• Acceptance Date: Jun 30, 2021
• Online Publication Date: Jul 3, 2021
• Publication Date: 2021
• Deposit Date: Nov 15, 2021
• Publicly Available Date: Nov 15, 2021
• Journal: Physics Letters B
• Print ISSN: 0370-2693
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 820
• DOI: https://doi.org/10.1016/j.physletb.2021.136491