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Constraints on the parity-violating couplings of a new gauge boson

C. Bouchiat·P. Fayet
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Abstract

High-energy particle physics experiments allow for the possible existence of a new light, very weakly coupled, neutral gauge boson (the U boson). This one permits for light (spin-1/2 or spin-0) particles to be acceptable Dark Matter candidates, by inducing sufficient (stronger than weak) annihilation cross sections into e+e-. They could be responsible for the bright 511 keV gamma ray line observed by INTEGRAL from the galactic bulge. Such a new interaction may have important consequences, especially at lower energies. Parity-violation atomic-physics experiments provide strong constraints on such a U boson, if its couplings to quarks and electrons violate parity. With the constraints coming from an unobserved axionlike behaviour of this particle, they privilegiate a pure vector coupling of the U boson to quarks and leptons, unless the corresponding symmetry is broken sufficiently above the electroweak scale.

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C. Bouchiat, P. Fayet. 2004-10-19. Constraints on the parity-violating couplings of a new gauge boson. https://doi.org/10.1016/j.physletb.2004.12.065

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