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Alignment of 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 large number of hadrons. This can be considered as evidence for the existence of coplanar scattering of secondary particles in interaction of particles with superhigh energy, E 0 > ∼ 10 16 eV. Data analysis suggests that production of most aligned groups occurs low above the chamber and is characterized by a coplanar scattering and quasiscaling spectrum of secondaries in the fragmentation region.The most elaborated hypothesis for explanation of alignment is related to the quark-gluon string rupture. However, the problem of theoretical interpretation of our results still remains open.

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An unusual Centauro phenomenon in which cosmic rays enter the atmosphere producing tens of charged hadrons, but virtually no neutral pions, has been a mystery for more than 30 years. Since the discovery of Centauro I in 1972 by the Brazil-Japan Collaboration operating x-ray emulsion chambers at 5200 m on Mt. Chacaltaya in the Bolivian Andes, a variety of models have been proposed ͑including new types of interaction or the creation of new types of matter͒. Here we show that the solution to a long-standing scientific puzzle lies with the details of the Chacaltaya detector. The new analysis of the original Centauro I event reveals that there is a difference in the angle between the upper block and lower block events, so the two are not products of the same interaction. That leaves only the lower chamber data connected to the Centauro I event. It is shown that, with the revised understanding of the event, new physics is no longer required for the explanation.

We present a systematic study of the large asymmetries in neutral pion fraction distribution in high energy cosmic ray families (100 TeVϽE vis Ͻ700 TeV) detected at high mountain altitudes at Pamir ͑4300 m, 595 g/cm 2 ). With this in mind we have constructed robust observables, ratios of factorial moments, in experimental and simulated families in a similar way. We have found that our experimental data do not exclude the possibility of a DCC formation mechanism in high energy interactions. ͓S0556-2821͑99͒06901-5͔ PACS number͑s͒: 96.40.De, 13.85.Tp PHYSICAL REVIEW D, VOLUME 59, 054001 0556-2821/99/59͑5͒/054001͑6͒/$15.00