Probing spin-dependent dark matter interactions with 6Li

CRESST is one of the most prominent direct detection experiments for dark matter particles with subGeV/c(2) mass. One of the advantages of the CRESST experiment is the possibility to include a large variety of nuclides in the target material used to probe dark matter interactions. In this work, we discuss in particular the interactions of dark matter particles with protons and neutrons of Li-6. This is now possible thanks to new calculations on nuclear matrix elements of this specific isotope of Li. To show the potential of using this particular nuclide for probing dark matter interactions, we used the data collected previously by a CRESST prototype based on LiAlO2 and operated in an above ground test-facility at Max-Planck-Institut fur Physik in Munich, Germany. In particular, the inclusion of Li-6 in the limit calculation drastically improves the result obtained for spin-dependent interactions with neutrons in the whole mass range. The improvement is significant, greater than two order of magnitude for dark matter masses below 1 GeV/c(2), compared to the limit previously published with the same data.

Automated summary

CRESST is a significant experiment for detecting dark matter particles with subGeV/c(2) mass. The experiment has the advantage of including various nuclides in the target material to study dark matter interactions. This study focuses on the interactions between dark matter particles and protons/neutrons of Li-6, enabled by new calculations on nuclear matrix elements. By analyzing data collected from a CRESST prototype using LiAlO2 at Max-Planck-Institut fur Physik in Munich, Germany, the inclusion of Li-6 in the limit calculation greatly improves the results for spin-dependent interactions with neutrons in the entire mass range.