Stellar probes of dark sector-photon interactions

Abstract

Electromagnetically neutral dark sector particles may directly couple to the photon through higher dimensional effective operators. Considering electric and magnetic dipole moment, anapole moment, and charge radius interactions, we derive constraints from stellar energy loss in the Sun, horizontal branch and red giant stars, as well as from cooling of the proto-neutron star of SN1987A. We provide the exact formula for in-medium photon-mediated pair production to leading order in the dark coupling, and compute the energy loss rates explicitly for the most important processes, including a careful discussion on resonances and potential double counting between the processes. Stringent limits for dark states with masses below 3 keV (40 MeV) arise from red giant stars (SN1987A), implying an effective lower mass-scale of approximately 10 9 GeV (10 7 GeV) for mass-dimension five, and 100 GeV (2.5 TeV) for mass-dimension six operators as long as dark states stream freely; for the proto-neutron star, the trapping of dark states is also evaluated. Together with direct limits previously derived by us in Chu et al. (2018), this provides the first comprehensive overview of the viability of effective electromagnetic dark-state interactions below the GeV mass-scale.

Dark sector-photon interactions in proton-beam experiments

“…For dimension-5 operators, future experiments such as DUNE (10-year) and SHiP will improve the sensitivity by a factor of 2-3, and become stronger than LEP for m χ < 1 GeV due to their high intensity. It is worth pointing out that the astrophysical bound from SN1987A constrains the MeV-region below 10 −8 µ B [58], well below the current and projected experimental sensitivity. For dimension-6 operators, the production and detection rates of light dark states are even more sensitive to the center-of-mass energy, suggesting it is unlikely for low-energy experiments to play any role in the foreseeable future.…”

“…[48][49][50][51][52] and precision observables such as (g − 2) of the muon [53][54][55][56] or constraints on the running of the fine-structure constant [57] were worked out. These studies of electromagnetic moment dark states in the MeV-GeV mass bracket were then further complemented by a detailed astrophysical study of stellar cooling constraints, once the mass drops below the MeV case [58]; see also related [59].…”

Detecting Light Dark Matter with Magnons

“…[61] onto the gray contours in Fig. 1, e.g., excluding g χ g e m χ =Λ χ ∈ ð10 −12 ; 10 −10 Þm χ =m e for magnetic dipole DM from SN1987A-in this case, there is a large region of unconstrained parameter space above this band (even after imposing big bang nucleosynthesis constraints) [61], which can be fully covered by our projected magnon reach. The anapole model is more challenging to discover via magnons due to the high power of momentum suppression, but the magnon sensitivity region still accommodates viable UV models, such as those involving two dark photons [62] which evade astrophysical and cosmological bounds altogether.…”

“…On the other hand, if Λ χ ≳ Oð100 MeVÞ, we can map the constraints derived in Ref. [61] onto the gray contours in Fig. 1, e.g., excluding g χ g e m χ =Λ χ ∈ ð10 −12 ; 10 −10 Þm χ =m e for magnetic dipole DM from SN1987A-in this case, there is a large region of unconstrained parameter space above this band (even after imposing big bang nucleosynthesis constraints) [61], which can be fully covered by our projected magnon reach.…”

Plasmon production from dark matter scattering

“…Plasmons can significantly impact several aspects of dark matter production and detection. Dark sector particles can be produced through plasmon decay or conversion in stars [32,[62][63][64][65][66][67][68] or in the early universe [69]. Plasmons also play a role in the interaction of charged DM in Galactic dynamics [70].…”