The Exponentially Modified Gaussian Function as a Tool for Deconvolution of Astroparticle Physics data.
| dc.contributor.author | Ochilo, Livingstone | |
| dc.date.accessioned | 2020-11-04T13:39:29Z | |
| dc.date.available | 2020-11-04T13:39:29Z | |
| dc.date.issued | 2016-03 | |
| dc.identifier.uri | http://ir.jooust.ac.ke:8080/xmlui/handle/123456789/8858 | |
| dc.description.abstract | An analysis of the mass composition of UHECRs based on the Xmax elongation rate (ER) within the energy range 1017.8−1020.0eV is performed, using Xmax data collected by the Pierre Auger Observatory from December 2004 to December 2012.The development of ER with energy is investigated by estimating the ER and the rate of change of ER with energy in sliding windows. In order to make it easier to observe the effect of a change in the proton fraction on the overall primary cosmic ray composition, the data has been truncated into ‘light’ and ‘heavy’ components based on a cut on the Xmax value above which 50% of helium showers produced with EPOS-LHC survive. The ‘light’ component should be dominated by proton and helium nuclei. The behavior of the ER of the ‘light’ part potentially allows one to distinguish changes in the mass composition from changes in the properties of hadronic interactions. The rate of change of ER with energy is observed to be negative and differs from zero for lg(E/eV)≈18.2−18.5 by∼3σ: primary mass is increasing and the rate of change of primary mass might not be constant. The increase in primary mass might be mostly due to a reduction of the fraction of protons. The ‘heavy’ subset seems to be consistent with a constant primary mass. An interpretation of the data as being due to a pure proton composition with an unexpectedly large increase in interaction cross-section might be in tension with the behavior of ER of the ‘light’ component. | en_US |
| dc.language.iso | en | en_US |
| dc.publisher | University of Siegen | en_US |
| dc.subject | mass composition of UHECRs | en_US |
| dc.subject | Xmax elongation rate | en_US |
| dc.title | The Exponentially Modified Gaussian Function as a Tool for Deconvolution of Astroparticle Physics data. | en_US |
| dc.type | Thesis | en_US |
