Speaker
Description
The axion was initially posed as a solution to the CP problem of QCD, but axion-like particles (ALPs) also arise in string theory and are a dark matter (DM) candidate. Most laboratory axion searches concentrate on the 0.001-0.1 meV mass range, however there is growing interest in heavier (DFSZ) axions (above 10 meV) which avoid the cosmological domain wall catastrophe[1] and may explain stellar energy losses beyond those accounted for by neutrino emission[2].
Here we describe new laboratory searches for axions performed at EuXFEL. These are sensitive to an axion/ALP mass range including 1 meV-1 eV, which is unconstrained by astrophysical arguments if axions constitute DM. Similar searches were previously performed on a 3rd generation synchrotron[3]; however limited flux prevented those experiments probing down to DM relevant couplings. This work is the first step in developing a platform with improved sensitivity due to an increase in brightness by $\sim10^{10}$ when using EuXFEL. Initial work has confirmed previous bounds on the axion-photon coupling[3] and considered a previously unexplored axion mass range. In future we expect to probe down to the coupling in the keV mass range for which QCD axions can be DM.
[1]K.Beyer & S.Sarkar arXiv:2211.14635v5. (2023)
[2]M.Giannotti+ JCAP 2017.10 (2017)
[3]T.Yamaji+ Phys.Lett.B 782, 523–527 (2018)
Funded by the UK EPSRC (EP/X01133X/1 & EP/X010791/1). SS & GG are members of the QSHS consortium funded by the UK STFC (ST/T006277/1).
| Submitted on behalf of a Collaboration? | No |
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