PASSAT: particle accelerator helioScopes for Slim Axion-like-particle deTection

Abstract

We propose a novel method to search for axion-like particles (ALPs) at particle accelerator experiments. ALPs produced at the target via the Primakoff effect subsequently enter a region with a magnetic field, where they are converted to photons that are then detected. Dubbed Particle Accelerator helioScopes for Slim Axion-like-particle deTection (PASSAT), our proposal uses the principle of the axion helioscope but replaces ALPs produced in the Sun with those produced in a target material. Since we rely on ALP-photon conversions, our proposal probes light (slim) ALPs that are otherwise inaccessible to laboratory-based experiments which rely on ALP decay, and complements astrophysical probes that are more model-dependent. As a first application, we reinterpret existing data from the NOMAD experiment in light of PASSAT, and constrain the parameter space for ALPs lighter than ∼ 100 eV and ALP-photon coupling larger than ∼ 10 −4 GeV −1 . As benchmarks of feasible low-cost experiments improving over the NOMAD limits, we study the possibility of reusing the magnets of the CAST and the proposed BabyIAXO experiments and placing them at the proposed BDF facility at CERN, together with some new detectors. We find that these realizations of PASSAT allow for a direct probe of the parameter space for ALPs lighter than ∼ 100 eV and ALP-photon coupling larger than ∼ 4 × 10 −6 GeV −1 , which are regions that have not been probed yet by experiments with laboratory-produced ALPs. In contrast to other proposals aiming at detecting single or two-photon only events in hadronic beam dump environments, that rely heavily on Monte Carlo simulations, the background in our proposal can be directly measured in-situ, its suppression optimized, and the irreducible background statistically subtracted. Sensitivity evaluations with other beams will be the subject of a future paper. The measurements suggested in this paper represent an additional physics case for the BDF at CERN beyond those already proposed.

Implications of the XENON1T excess on the dark matter interpretation

“…[28][29][30][31][32][33][34], for which concise summaries are referred to Refs. [35,36]. Furthermore, Ref.…”

Exploring the robustness of stellar cooling constraints on light particles

“…However, the mechanism proposed in this paper is different from those previously proposed in that it employs a light scalar field to generate large masses for new particles within stars, a mechanism that is generically applicable to a wide variety of models of new physics. In light of recent results from the EDGES and Xenon1T collaborations that suggest new physics in regions of parameter space solely excluded by stellar cooling, we demonstrate that this mechanism can reopen parameter space and motivate new experimental searches in "excluded" regions [10,11].…”

Axions: From Magnetars and Neutron Star Mergers to Beam Dumps and BECs

“…The laboratory-produced ALP searches are extensively performed in beam-dump type experiments (i.e., fixed target experiments) including E137 [297], E141 [298], reanalyses [299] of CHARM [300] and NuCal [301] ALP searches, NOMAD [302], and NA64 [280], and reactor experiments [303][304][305][306][307][308][309][310][311] for the past decades, and an increasing number of studies have pointed out that the next-generation beam neutrino experiments [277,299,[312][313][314][315][316][317][318][319] and high-power reactor neutrino experiments [285,293] can explore a wider range of ALP parameter space. 15 We provide summaries tabulating key specifications of existing and future beam-dump type (neutrino) experiments in Table I 16 and reactor (neutrino) experiments in Table II.…”

“…One may estimate the photon fluxes induced by the first two mechanisms (semi-)analytically. For example, production of pions through energetic proton beams on target is empirically parametrized by the Sanford-Wang description [332] and the BMPT model [333], and their decay photons can be used as an injection photon flux [316]. For another example, the equivalent photon approximation, also known as Fermi-Weizsäker-Williams method [334][335][336], provides a convenient framework to estimate bremsstrahlung photons from an energetic charged particle.…”

“…[349,350], LSW-type experiments [351], NOMAD [302], and beam-dump experiments [297]. Future expected limits include a PASSAT interpretation [316] of NOMAD [302], PASSAT implementations at the BDF facility with the CAST or BabyIAXO magnets with 2 × 10 20 POTs [316], a PASSAT implementation at the DUNE MPD with a 7-year exposure [319], PASSAT implementations at DUNE with the CAST or BabyIAXO magnets with a 7-year exposure [319], and reactor searches at CONNIE, CONUS, and MINER [285]. Right panel: Limits for ma > 10 MeV to which the decay channels in beam-dump and reactor neutrino experiments are relevant.…”