Speaker
Description
We present an updated analysis of the mass composition of cosmic rays in the $10^{17}$ to $10^{18}$ eV energy range. It is based on radio measurements of the depth of shower maximum $X_{\rm max}$, done with the LOFAR telescope.
We review the improvements to the reconstruction setup based on Corsika/CoREAS simulations, as well as the selection method to obtain a minimally biased $X_{\rm max}$-dataset. Systematic uncertainties on Xmax have been lowered to an estimated 7 to 9 g/cm$^2$, at a resolution of 20 g/cm$^2$ per shower.
Results include estimates of the mean and standard deviation of the $X_{\rm max}$-distribution. A statistical analysis at distribution level has been done as well, using a four-component model of light to heavy nuclei.
It confirms our previous results showing a significant low-mass fraction in this energy range.
We discuss consistency with existing results on $X_{\rm max}$ and mass composition.
