Polarized light propagating in a magnetic field as a probe of millicharged fermions

Gies, Holger; Jaeckel, Joerg; Ringwald, Andreas

Abstract

Possible extensions of the standard model of particle physics suggest the existence of particles with small, unquantized electric charge. Photon-initiated pair production of millicharged fermions in a magnetic field would manifest itself as a vacuum magnetic (VM) dichroism. We show that laser polarization experiments searching for this effect yield, in the mass range below 0.1 eV, much stronger constraints on millicharged fermions than previous laboratory searches. VM birefringence due to virtual pair production gives a slightly better constraint for masses between 0.1 and a few eV. We comment on the possibility that the VM dichroism observed by PVLAS arises from pair production of such millicharged fermions rather than from single production of axionlike particles. Such a scenario can be confirmed or firmly excluded by a search for invisible decays of orthopositronium with a branching-fraction sensitivity of about 10-9.

Citation

Gies, H., Jaeckel, J., & Ringwald, A. (2006). Polarized light propagating in a magnetic field as a probe of millicharged fermions. Physical Review Letters, 97, https://doi.org/10.1103/physrevlett.97.140402

• Journal Article Type: Article
• Publication Date: Oct 1, 2006
• Deposit Date: Apr 28, 2008
• Publicly Available Date: Apr 28, 2008
• Journal: Physical Review Letters
• Print ISSN: 0031-9007
• Electronic ISSN: 1079-7114
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 97
• DOI: https://doi.org/10.1103/physrevlett.97.140402
• Public URL: https://durham-repository.worktribe.com/output/1535914
• Publisher URL: http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000097000014140402000001&idtype=cvips&gifs=yes