000K utf8 1500 eng 2050 urn:nbn:de:gbv:8:3-2023-00521-8 2051 10.38072/2748-3150/p43 3000 Livada, Maria 3010 Dimosthenous, Nafsika 3010 Mavromichalaki, Helen 3010 Xaplanteris, Loukas 4000 Neutron monitor yield function: improved spectral computations of the Forbush decrease of June 2015 [Livada, Maria] 4209 In this work a new improved coupling function by Xaplanteris et al. (2021) based on Quantum Field Theory is applied for spectral analysis of cosmic rays. This new coupling function had already been confirmed in the application of cosmic rays with the calculation of primary cosmic ray intensity during Forbush decreases and ground level enhancements but this is the first time that it is used for the calculation of spectral index. To describe the rigidity spectrum of the galactic cosmic ray (GCR) during a Forbush decrease, a power law in rigidity is often used. The exponent of this power law, the spectral index, describes the hardness of the GCR spectrum. The spectrum of the GCR becomes harder during the Forbush decrease main phase. For this analysis the Forbush decrease of the cosmic ray intensity observed on June 2015 was chosen. Daily cosmic ray data of the neutron monitor stations obtained from the high-resolution neutron monitor database (NMDB) were used for calculating the cosmic ray density and anisotropy variations. For the spectral analysis of the galactic cosmic rays the technique of Wawrzynczak and Alania (2010) is applied, based on the coupling coefficient method. The obtained results of the Fd analysis by using the new coupling function by Xaplanteris et al. (2021) are compared with the results obtained based on the coupling function by Clem and Dorman (2000). 4950 https://doi.org/10.38072/2748-3150/p43$xR$3Volltext$534 4950 https://nbn-resolving.org/urn:nbn:de:gbv:8:3-2023-00521-8$xR$3Volltext$534 4961 https://macau.uni-kiel.de/receive/macau_mods_00003843 5051 530 5051 600 5550 Forbush decreases 5550 galactic cosmic rays 5550 neutron monitors 5550 spectral analysis 5550 yield functions