On the nature of gamma-hadron family alignment

LHC data and cosmic ray coplanarity at superhigh energies

“…A tendency to a coplanarity of the most energetic cores of γ -ray-hadron families observed was first found by the Pamir Collaboration [19][20][21][22][23] and confirmed later in [24][25][26][27]. The probability W f luct tot for the total set of these experimental results to be produced by cascade fluctuations is much lower than 10 −10 [1,28].…”

FANSY 1.0: a phenomenological model for simulation of coplanar particle generation in superhigh-energy hadron interactions

“…On the other hand, such a robust and transparent phenomenon is observed at these energies as a tendency for a coplanarity of most energetic cores of so called γ -ray-hadron families, i.e., groups of highest-energy (E n · 1 TeV) particles in EAS cores). The effect has been first found by the Pamir Collaboration in X-ray-emulsion chamber (XREC) experiments [1][2][3][4][5] and confirmed later in other mountain [6] and stratospheric [7][8][9][10] experiments. While assuming this observable effect to be produced by well-known elementary a e-mail: muhamed@sci.lebedev.ru particles, it is related to hadron-nucleus interactions at superhigh energies (E 0 10 16 eV [11], i.e., √ s 4 TeV) and can be characterized by large average transverse momenta, for instance, up to ∼ n × 10 GeV/c as early as at E 0 ∼ 10 16 eV [12,13].…”

“…Pamir (Pb-XREC) λ 4 ≥ 0.8, E γ ≥ 700 TeV 6 from 14 0.43 ± 0.13 [3] Pamir (C-XREC) λ 4 ≥ 0.8, E γ ≥ 700 TeV 5 from 35 0.15 ± 0.05 [5] Mt.Kanbala (Fe-XREC) λ 3 ≥ 0.8, E γ ≥ 500 TeV 6 from 12 0.5 ± 0.13 [6] the Strana λ 4 = 0.99, E γ 1500 TeV 1 1 [12,13] the JF2af2 the decascading algorithm with z c = 5 TeV·cm for Pamir's XRECs [11,28] Let us attempt to find estimates of probabilities, w i , to gain the real (or larger) experimental number of coplanar families in the framework of different FANSY's versions. Results are shown in Table 4.3.…”

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

“…A connection of alignment to the production of secondaries with high transverse momentum was suggested e.g. in [13,14]. The appearance of an anti-shadow scattering mode at high collision energies as source of alignment was discussed in [21].…”

“…Simulations based on phenomenological models were compared to the PAMIR data in [14,23]. It was pointed out that alignment features produced, e.g., in the first interaction of the primary cosmic ray in air can be washed out by subsequent interactions during the shower evolution.…”