Theoretical Approach to Alignment Phenomenon

Abstract

An explanation of the puzzling alignment effect observed in cosmic ray experiments is suggested Few years ago the observation has been made [1] in cosmic ray experiments that the alignment of the main energy fluxes along a straight line in target (transverse) plane exceeds significantly the background level. More precisely, at superhigh energies of initial particle (E 0 ≥ 10 4 TeV) the secondary particle superfamilies detected by deep lead X-ray emulsion chamber appeared to be situated almost along straight line in target plane (Fig.1). The coplanar scattering of such a type was so surprising that an attempt has been made to revise the result but instead they were confirmed with much better confidence level [2]. The analysis of the alignment effect for 74 high energy γ-families induced by hadrons above and within the chamber has been carried out. Their energies energies are selected to be E γ = 100 ÷ 5000 TeV (hadron energies being restored, accounting that the energy of induced γ-family is about 1/3 of the hadron energy it is originated from). This analysis suggested that superfamily production happened predominantly rather low above the chamber (at the altitude H ≃ 2km, since it seemed that nuclearelectromagnetic cascade development would blur alignment, if several interactions contributed). It confirmed a coplanar scattering and scaling-like fragmentation spectrum of energy distinguished cores. The alignment parameter λ, −0.5 ≤ λ = m i =j =k cos(2φ ijk ) m(m − 1)(m − 2) ≤ 1,

Tests of hadronic interaction models by data of the KASCADE-Grande air-shower experiment

“…Geometric structures in hadronic shower cores at observation level are particularly interesting, as one expects QCD jet production to lead to secondary hadrons being naturally aligned to form line shape patterns [32]. Similar alignment structures might result from exotic hadron production processes [33]. Aligned event structures were, for instance, reported by the PAMIR experiment [34,35,36].…”

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

“…4d in [14]) [15], semihard double diffraction dissociation, which assumes the coplanarity to be a result of a QGS tension in the diffraction cluster between a semihardly scattered constituent quark and other spectator quarks of the projectile hadron and its following rupture (Fig. 4b in [14]) [16]; projectile's diquark breaking [17]; appearance of very-high-spin leading systems [18,19]. This problem seems to be likely resolved by using the first two approaches.…”

“…Several approaches have been proposed [15][16][17][18][19] until now. One cannot exclude other approaches.…”

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

“…Similar alignment structures might result from exotic hadron production processes [8]. Therefore, it is not surprising that the observation of aligned structures in a number of emulsion chamber experiments has initiated considerable experimental and theoretical efforts over the last two decades [7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26].…”

“…The appearance of an anti-shadow scattering mode at high collision energies as source of alignment was discussed in [21]. An onset of semi-hard double inelastic diffraction was proposed in [8], where alignment results as projection from the rupture of a quark-gluon string. The existence of a new particle with a long mean free path, produced in a new type of interaction, was also proposed to explain the PAMIR observation [15,22].…”