Optimizing light-shining-through-a-wall experiments for axion and other weakly interacting slim particle searches

Abstract

One of the prime tools to search for new light bosons interacting very weakly with photons -prominent examples are axions, axion-like particles and extra "hidden" U(1) gauge bosons -are light-shining-through-a-wall (LSW) experiments. With the current generation of these experiments finishing data taking it is time to plan for the next and search for an optimal setup. The main challenges are clear: on the one hand we want to improve the sensitivity towards smaller couplings, on the other hand we also want to increase the mass range to which the experiments are sensitive. Our main example are axion(-like particle)s but we also discuss implications for other WISPs (weakly interacting slim particles) such as hidden U(1) gauge bosons. To improve the sensitivity for axions towards smaller couplings one can use multiple magnets to increase the length of the interaction region. However, naively the price to pay is that the mass range is limited to smaller masses. We discuss how one can optimize the arrangement of magnets (both in field direction as well as allowing for possible gaps in between) to ameliorate this problem. Moreover, future experiments will include resonant, high quality optical cavities in both the production and the regeneration region. To achieve the necessary high quality of the cavities we need to avoid too high diffraction losses. This leads to minimum requirements on the diameter of the laser beam and therefore on the aperture of the cavity. We investigate what can be achieved with currently available magnets and desirable features for future ones.

Proposal for a Cosmic Axion Spin Precession Experiment (CASPEr)

“…It is also sensitive to ALPs that couple to the nucleon EDM, probing sources of symmetry breaking in the ALP sector. The signal in this solid-state NMR-based experiment benefits from the large number (≳10 22 ) of spins in a solid-state system. In conjunction with precision magnetometers, this approach enables sensitivity to this region of parameter space using current technology.…”

“…The energy density in these oscillations can be dark matter [15,16]. Other types of light bosons, often called axionlike particles (ALPs), have attracted significant attention [17][18][19][20][21][22][23][24][25][26][27][28][29][30]. These receive a potential (and a mass) from non-QCD sources and are less constrained than the QCD axion.…”

TeV‐ and MeV‐Physics Out of an Model

“…On the other hand, there has been in the literature a great deal of interest on the activity related to the phenomenology of the so-called hidden sector para-photons and millicharged particles [17][18][19]. In this rich framework, we pursue an investigation to understand whether our proposal could fit to describe physics at the Sub-eV scale of the para-photons.…”

Mixing of photons with light pseudoscalars in time-dependent magnetic fields

“…In the limit m φ ω, and recalling that in resonance λ ≈ m 2 φ /(2ω) = q, we see that the potential gain in probability would be P res This enhancement translates into a gain in sensitivity of three orders of magnitude for the coupling constant g, keeping in mind that a measuring time of 1 h is a conservative estimate, according to the upgrades envisaged for these kinds of experiments [29].…”