Konstantin Beyer

Abstract:

We investigate the prospect of an alternative laboratory-based search for the coupling of axions and axionlike particles to photons. Here, the collision of two laser beams resonantly produces axions, and a signal photon is detected after magnetic reconversion, as in light-shining-through-walls (LSW) experiments. Conventional searches, such as LSW or anomalous birefringence measurements, are most sensitive to axion masses for which substantial coherence can be achieved; this is usually well below optical energies. We find that using currently available high-power laser facilities, the bounds that can be achieved by our approach outperform traditional LSW at axion masses between 0.5–6 eV, set by the optical laser frequencies and collision angle. These bounds can be further improved through coherent scattering off laser substructures, probing axion-photon couplings down to gaγγ∼10−8GeV−1, comparable with existing CAST bounds. Assuming a day long measurement per angular step, the QCD axion band can be reached.

Abstract:

With the advent of high power lasers, new opportunities have opened up for simulating astrophysical processes in the laboratory. We show that 2nd-order Fermi acceleration can be directly investigated at the National Ignition Facility, Livermore. This requires measuring the momentumspace diffusion of 3 MeV protons produced within a turbulent plasma generated by a laser. Treating Fermi acceleration as a biased diffusion process, we show analytically that a measurable broadening of the initial proton distribution is then expected for particles exiting the plasma.

Abstract:

The collision of two real photons can result in the emission of axions. We investigate the performance of a modified light-shining-through-wall (LSW) axion search aiming to overcome the large signal suppression for axion masses ma ≥ 1 eV. We propose to utilize a third beam to stimulate the reconversion of axions into a measurable signal. We thereby find that with currently available high-power laser facilities we expect bounds at axion masses between 0.5–6 eV reaching gaγγ ≥ 10−7 GeV−1. Combining the use of optical lasers with currently operating x-ray free electron lasers, we extend the mass range to 10–100 eV.

Abstract:

The collision of two real photons can result in the emission of axions. We investigate the performance of a modified light-shining-through-wall (LSW) axion search aiming to overcome the large signal suppression for axion masses $m_a\geq 1 \text{eV}$. We propose to utilise a third beam to stimulate the reconversion of axions into a measurable signal. We thereby find that with currently available high-power laser facilities we expect bounds at axion masses between $0.5-6\text{eV}$ reaching $g_{a\gamma\gamma}\geq 10^{-7}\text{GeV}^{-1}$. Combining the use of optical lasers with currently operating x-ray free electron lasers, we extend the mass range to $10-100\text{eV}$.