Coplanar emission of neutral and charged components of gamma-hadron families at energies 1015 – 1017 eV

Geometric structures in hadronic cores of extensive air showers observed by KASCADE

“…9, the λ 4 distributions obtained from KAS-CADE and PAMIR data [11,15] are compared for two different primary energies. In the energy range of a few PeV (upper panel of the Figure), i.e.…”

“…For a higher primary energy range, based on λ 4 distributions obtained from PAMIR data such as shown in [11,15] data. In the lower panel, the highest primary energies are selected.…”

“…In the lower panel, the highest primary energies are selected. The two distributions displayed for PAMIR in the lower panel refer to different reconstructions from the same PAMIR data set [11,15]. PAMIR data are slightly displaced horizontally.…”

“…Similar alignment structures might result from exotic hadron production processes [8]. Therefore, it is not surprising that the observation of aligned structures in a number of emulsion chamber experiments has initiated considerable experimental and theoretical efforts over the last two decades [7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26]. Aligned event structures were, for instance, reported by the PAMIR experiment [9,10].…”

“…An excess of events with substructure alignment above background fluctuations was found in the data for primary energies above an energy threshold of 8−10 PeV (see e.g. [10,11,12,13,14,15] and references therein). The most energetic event of ≃10 PeV that was measured in an emulsion experiment during flights with the Concorde airplane also shows alignment [16].…”