New method of probing an oscillating EDM induced by axionlike dark matter using an rf Wien filter in storage rings

Abstract

A hypothetical pseudo-scalar particle axion, which is an immediate result of the Peccei-Quinn solution to the strong CP problem, may couple to gluons and lead to an oscillating electric dipole moment (EDM) of fundamental particles. This paper proposes a novel method of probing the axioninduced oscillating EDM in storage rings, using a radiofrequency (RF) Wien Filter. The Wien Filter at the frequency of the sidebands of the axion and g − 2 frequency, faxion ± fg−2, generates a spin resonance in the presence of an oscillating EDM, as confirmed both by an analytical estimation of the spin equations and independently by simulation. A brief systematic study also shows that this method is unlikely to be limited by Wien Filter misalignment issues.

The storage ring proton EDM experiment

“…In preparing for the technical design report (TDR), we will assess the relevant concepts and techniques that have been studied so far [3,4,23,[28][29][30][31][32][33][34][35][36][37][38][39][40][41][42]. We will also:…”

“…• Sensitive to dark matter, vector dark matter/dark energy (DM/DE) models [3,4]. DM/DE signal proportional to β = v/c.…”

Electric dipole moments and the search for new physics

“…Such a ring requires a large electric field (≈ 10MV/m) and a proton momentum of 707 MeV/c, resulting in a storage ring of ≈ 500 m circumference. Recently, it was realized that, before starting the construction of a such a ring, an intermediate step, a so-called prototype with approximately 100 m circumference, is needed, which demonstrates the functionality of all components and allows for a first direct measurement of the proton EDM as well as searches for axions/axion-like-particles [360][361][362]. The current state-of-the-art of the development is summarized in a recent CERN Yellow Report [89].…”

“…Under optimized running conditions, where the beam storage duration is for half the SCT, the EDM statistical sensitivity of the method is given by [362], where P 0 (∼ 0.8) is the horizontal beam polarization, A (∼ 0.6) is the asymmetry, E (3.3 MV/m = 4.4 MV/m × 600 m/800 m) is the average radial electric field integrated around the ring, k (1%) is the polarimeter detector efficiency, N cyc (∼ 2 × 10 10 ) is the stored particles per cycle, T exp (1 × 10 8 s) is the total duration of the experiment and τ p (2 × 10 3 s) is the in-plane (horizontal) beam polarization lifetime (equivalent to SCT). The SCT of 2 × 10 3 s, i.e., an optimum storage time of 10 3 s, is assumed here in order to achieve a statistical sensitivity at 10 −29 e • cm level, while assuming the total experiment duration is 80 million seconds (in practice, corresponding to roughly five calendar years).…”

General relativity effects in precision spin experimental tests of fundamental symmetries

“…In the scheme adopted in the JEDI experiment, the spin of the bunch of deuterons lies in the ring plane and the linear in time accumulation of the vertical polarization serves as an axion signal [61,428,429,434]. All the other RF spin rotators in the ring, including the RF Wien filter discussed in [435], are better switched off.…”