On the methods to determine signal attenuation curve for different surface arrays

TL;DR

This paper investigates various methods for determining the signal attenuation curve in surface arrays of cosmic ray experiments, analyzing how assumptions in these methods can influence physics results like energy spectrum and anisotropy detection.

Contribution

It provides a comparative analysis of different attenuation curve determination methods using Toy Monte Carlo and CORSIKA simulations, highlighting potential biases.

Findings

Assumptions in attenuation curve methods can bias energy spectrum results.

Different surface array sensitivities affect attenuation correction accuracy.

Methodological choices influence anisotropy and composition analyses.

Abstract

Large surface arrays of current cosmic ray experiments measure the signals of electromagnetic or muonic components or their combination. The correction to the zenith angle (the attenuation curve) has to be taken into account before the signal is converted to the shower energy. Either Monte Carlo simulations or indirect estimation using collected data (Constant Intensity Cut method) can be used. However, the assumptions of composition or isotropy used for the determination of the attenuation curve can still influence the final physics results such as the energy spectrum, or modify anisotropy searches and composition analysis. Using simplified Toy Monte Carlo with an output from CORSIKA simulations we try to find several examples of what kind of effects can be caused by the methods of inferring the attenuation curve. Surface arrays of different sensitivities to electromagnetic and muonic components were considered.