Results of emulsion chamber experiments with very high-energy cosmic rays which are difficult to explain in the framework of the standard model

Abstract

Recent results of emulsion chamber experiments on the observation of unusual events and new phenomena in cosmic ray particle interactions in the energy range beyond 10 PeV are presented in this review. Particular attention is given to the following items: 1. 1. Centauro-type events with violation of charge (isotopic) symmetry in hadron production; 2. 2. fan-shaped events which argue in favour of a new mechanism of coplanar emission of secondaries; 3. 3. events with halos produced by collimated bundles of high energy gammas and hadrons; 4. 4. penetrating hadrons with abnormal absorption in lead. The present paper contains main characteristics of the events and phenomena under review as well as discussion of their possible interpretation. It is conceivable that the observed events are the manifestation of New Physics beyond the Standard Model. Further progress in studying the new phenomena in cosmic ray experiments for the next few years, in view of LHC startup, is considered.