Revision of the energy calibration of the Yakutsk extensive air shower array

Abstract

Responses of surface and underground scintillation detectors of Yakutsk array are calculated for showers initiated by primary particles with energy E 0 ≥ 10 17 eV within the frameworks of QGSJet01d, QGSJet-II-04, SIBYLL-2.1 and EPOS-LHC hadron interaction models. A new estimation of E 0 is obtained with the use of various methods. The resulting energy is lower compared to the obtained with earlier method by factor ∼ 1.33.

Energy spectrum of ultra-high energy cosmic rays according to surface detectors of Yakutsk EAS array

“…Calculations have revealed, that in relations (1.1) and (1.4) the energy dissipated in the atmosphere in the form of electromagnetic component, was overestimated by (12)(13)(14)(15)(16)(17)% depending on the shower maximum x max (see Fig. 2).…”

“…FLUKA model [22] was chosen for treatment of of low energy hadron interactions. The details of the detector response estimation were outlined in [15,16].…”

“…is the fraction of primary energy carried by electrons and positrons to the observation level. It was estimated by integrating the differential energy deposit over the cascade curve N e (x) below the observation level x obs (see [15,16]).…”

“…The intensity of CR spectrum derived from (1.4) was significantly higher than all the world data. In works [15,16] we reconsidered the energy calibration of the array with the use of CORSIKA program [17] which is described further.…”

Search for ultra high energy primary photons at the Pierre Auger Observatory

“…3(a). The cut was chosen at the mean of the Fisher distribution for photons so the photon detection efficiency is 50% by [7]), from AGASA (A) [11] and Yakutsk (Y) [15]. The shaded region and the lines give predictions for the GZK photon flux [17] and for "top-down" models (TD, Z-Burst, SHDM from [17] and SHDM' from [18]).…”