Towards a cosmic-ray mass-composition study at Tunka Radio Extension

D Kostunin,R Hiller,L A Kuzmichev,M Kleifges,R Wischnewski,A Haungs,O Krömer,Oleg Fedorov ,В В Просин ,Р Р Миргазов ,P A Bezyazeekov,Н Лубсандоржиев ,Г Рубцов ,T Huege ,Р Монхоев ,V Kungel ,O Gress ,Е Е Коростелева ,E Osipova ,L Pankov,А Пахоруков ,Y Kazarina ,Н М Буднев ,Frank G Schröder ,А Загородников

doi:10.1051/epjconf/201713501005

Abstract

The Tunka Radio Extension (Tunka-Rex) is a radio detector at the TAIGA facility located in Siberia nearby the southern tip of Lake Baikal. Tunka-Rex measures air-showers induced by high-energy cosmic rays, in particular, the lateral distribution of the radio pulses. The depth of the air-shower maximum, which statistically depends on the mass of the primary particle, is determined from the slope of the lateral distribution function (LDF). Using a model-independent approach, we have studied possible features of the one-dimensional slope method and tried to find improvements for the reconstruction of primary mass. To study the systematic uncertainties given by different primary particles, we have performed simulations using the CONEX and CoREAS software packages of the recently released CORSIKA v7.5 including the modern high-energy hadronic models QGSJet-II.04 and EPOS-LHC. The simulations have shown that the largest systematic uncertainty in the energy deposit is due to the unknown primary particle. Finally, we studied the relation between the polarization and the asymmetry of the LDF.

Highlights

The Tunka Radio Extension (Tunka-Rex) is a radio detector at the TAIGA facility located in Siberia nearby the southern tip of Lake Baikal
The asymmetry caused by interference between the Askaryan effect and the geomagnetic effect has already been treated within all modern approaches, and has been measured by means of the polarization study [8, 9]
In the work [5] it is shown that the charge-excess asymmetry has a non-trivial dependence on the distance to the shower axis, the asymmetry features a local maximum depending on the distance to the shower maximum

Summary

Introduction

Parameters, describing two gaussian functions shifted respective to each other) [6]; and the straightforward LOFAR approach (full simulation of radio footprints for each antenna position) [7]. The asymmetry caused by interference between the Askaryan effect and the geomagnetic effect has already been treated within all modern approaches, and has been measured by means of the polarization study [8, 9]. In the present paper we will discuss its impact on the lateral distribution and the connection of the asymmetry with the shower maximum. We study the model-independent behavior of the radio emission, we check the influence and uncertainties given by different hadronic models. We discuss possible improvements for the reconstruction of the shower maximum

Model-independent considerations and model-dependent uncertainties

Hints from the charge-excess asymmetry

Summary