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

Gies, Holger; Jaeckel, Joerg; Ringwald, Andreas

doi:10.1103/physrevlett.97.140402

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

Gies, Holger; Jaeckel, Joerg; Ringwald, Andreas

Authors

Holger Gies

Joerg Jaeckel

Andreas Ringwald

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
Publisher URL	http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000097000014140402000001&idtype=cvips&gifs=yes