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 measurements with the LOFAR telescope of the depth of shower maximum, $X_{\mathrm{max}}$.
We review the improvements to the simulation-based reconstruction setup, as well as the selection method to obtain a minimally biased $X_\mathrm{max}$-dataset. Systematic uncertainties on $X_\mathrm{max}$ have been lowered to an estimated 7 to 9 $\mathrm{g/cm^2}$, at a resolution of about 20 $\mathrm{g/cm^2}$ per shower.
Results include estimates of the mean and standard deviation of the $X_\mathrm{max}$-distribution. A statistical analysis at distribution level has been done as well, using a 4-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 Xmax and mass composition.
Keywords
air showers; cosmic rays; mass composition; shower maximum; Xmax
| Subcategory | Experimental Results |
|---|---|
| Collaboration | LOFAR |
