Alignment in γ-hadron families of cosmic rays

Alignment of the main fluxes of energy in a target plane is found in families of cosmic ray particles detected in deep lead x-ray chambers. The fraction of events with alignment is unexpectedly large for families with high energy and a large number of hadrons. This can be considered as evidence for the existence of coplanar scattering of secondary particles in the interaction of particles with superhigh energy, ${\mathit{E}}_{0}$\ensuremath{\gtrsim}${10}^{16}$ eV. Data analysis suggests that the production of most aligned groups occurs slightly above the chamber and is characterized by a coplanar scattering and quasiscaling spectrum of secondaries in the fragmentation region. The most elaborated hypothesis for the explanation of alignment is related to the quark-gluon string rupture. However, the problem of the theoretical interpretation of our results still remains open.