# ICRC 2021

Jul 12 – 23, 2021
Online
Europe/Berlin timezone

## Results on mass composition of cosmic rays as measured with LOFAR

Jul 13, 2021, 6:00 PM
1h 30m
03

#### 03

Talk CRI | Cosmic Ray Indirect

### Speaker

Arthur Corstanje (Free University Brussels)

### 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

Collaboration LOFAR Experimental Results

### Primary authors

Arthur Corstanje (Free University Brussels)

### Presentation materials

There are no materials yet.