High-precision search for dark photon dark matter with the Parkes Pulsar Timing Array

Abstract

The nature of dark matter remains obscure in spite of decades of experimental efforts. The mass of dark matter candidates can span a wide range, and its coupling with the Standard Model sector remains uncertain. All these unknowns make the detection of dark matter extremely challenging. Ultralight dark matter, with m ∼ 10 −22 eV, is proposed to reconcile the disagreements between observations and predictions from simulations of small-scale structures in the cold dark matter paradigm, while remaining consistent with other observations. Because of its large de Broglie wavelength and large local occupation number within galaxies, ultralight dark matter behaves like a coherently oscillating background field with an oscillating frequency dependent on its mass. If the dark matter particle is a spin-1 dark photon, such as the U(1) B or U(1) B−L gauge boson, it can induce an external oscillating force and lead to displacements of test masses. Such an effect would be observable in the form of periodic variations in the arrival times of radio pulses from highly stable millisecond pulsars. In this study, we search for evidence of ultralight dark photon dark matter (DPDM) using 14-year high-precision observations of 26 pulsars collected with the Parkes Pulsar Timing Array. While no statistically significant signal is found, we place constraints on coupling constants for the U(1) B and U(1) B−L DPDM. Compared with other experiments, the limits on the dimensionless coupling constant achieved in our study are improved by up to two orders of magnitude when the dark photon mass is smaller than 3 × 10 −22 eV (10 −22 eV) for the U(1) B (U(1) B−L ) scenario.

Neutron Stars with Baryon Number Violation, Probing Dark Sectors

“…[470,471]; the resulting exclusions are between one and two orders of magnitude weaker than the projection shown here. Similar projections have been made for other future GW observatories [472,473] as well as pulsar timing arrays [474,475]; see also Sec. V of Ref.…”

Neutron Stars with Baryon Number Violation, Probing Dark Sectors

“…[453,454]; the resulting exclusions are between one and two orders of magnitude weaker than the projection shown here. Similar projections have been made for other future GW observatories [455,456] as well as pulsar timing arrays [457,458]; see also Sec. V of Ref.…”

Vector wave dark matter and terrestrial quantum sensors

“…See figure 1 for a visualization and a description of this evolution, and visit this webpage for a video. Such elliptical motion is appropriately used in, for example, [66][67][68].…”