Delayed muons in extensive air showers and double-front showers

The results of a long-term experiment performed in the period between 1995 and 2006 with the aid of the MUON-T underground (20 mwe) scintillation facility arranged at the Tien Shan mountain research station at an altitude of 3340 m above sea level are presented. The time distribution of delayed muons with an energy in excess of 5 GeV in extensive air showers of energy not lower than 106 GeV with respect to the shower front was obtained with a high statistical significance in the delay interval between 30 and 150 ns. An effect of the geomagnetic field in detecting delayed muons in extensive air showers was discovered. This effect leads to the asymmetry of their appearance with respect to the north-south direction. The connection between delayed muons and extensive air showers featuring two fronts separated by a time interval of several tens of to two hundred nanoseconds is discussed. This connection gives sufficient grounds to assume that delayed muons originate from the decays of pions and kaons produced in the second, delayed, front of extensive air showers.     

Charge Transfer between Neutron-Induced and Activator Centers in LuAG:Pr Single Crystal

Optics and Spectroscopy - The spectra of absorption and gamma luminescence and integral thermoluminescence curves (300–605 K) of nominally pure LuAG crystals and praseodymium-doped LuAG:Pr...     

Determinability of a Completely Decomposable Block-Rigid Torsion-Free Abelian Group by Its Automorphism Group

In this paper, we consider the question of determinability of an Abelian group by its automorphism group in the class of completely decomposable block-rigid torsion-free Abelian groups.     

Retarded penetrating particles in EAS

We present the results of long-term (1995–2006) exploitation of the underground scintillation MUON-T unit at the Tien-Shan mountain scientific station. In 2000, the unit was supplied with a chronotron. The time distribution of retarded (relative to the EAS front) penetrating particles at a depth of 20 m.w.e. was obtained with high statistical confidence. The effect of the geomagnetic field on retardation of penetrating EAS particles, leading to asymmetry of their registration relative to the North-South direction, is confirmed.     

Kinetic Study of the Oxidation of Hydrogen Sulfide and Ethyl Mercaptan with Molecular Oxygen in the Presence of an Ammonia Solution of Cobalt Phthalocyanine Derivatives

Kinetics and Catalysis - The main kinetic tendencies in the individual oxidation of hydrogen sulfide and simultaneous oxidation of hydrogen sulfide and ethyl mercaptan with molecular oxygen in the...     

Superyoung EAS with N e>107. The ?Hadron? experiment

Summary The combined (EAS+EC) ?Hadron? experiment was made at Tien-Shan Station during 1985–1991. A large statistic of gamma-hadron families, combined with EAS, is now analysed. The result of the leader effect disappearance forN _e>10⁷ was reported earlier and at this Conference too. Here we present new results about the existence of Super Young Showers (SYS) with ageS<0.1, containing gamma-hadron families with visible energy ≥10 TeV. Namely, SYS have anomalous soft-energy spectra of particles at gamma-hadron families. These events may be connected with Young Air Showers (YAS) and Narrow Air Showers (NAS). Paper presented at the Special Session on very high-energy cosmic-ray interactions (superfamilies) of the XXIV International Cosmic-Ray Conference, Rome, August 28–September 8, 1995.     

Effect of the J–J Interaction of Excited States of the Rare-Earth Ion Pr3+ on Magnetically Polarized Luminescence of Praseodymium-Yttrium Aluminum Garnet

Physics of the Solid State - The spectra of luminescence and magnetic circular polarization of luminescence of praseodymium–yttrium aluminum garnet Pr3+ : Y3Al5O12 (PrYAG) are studied in the...     

Ortho-para splitting of the exciton ground state in a strong magnetic field

Exciton spectra in bulk semiconductor in strong magnetic fields were studied in the two-band Dirac model. An expression for the energy of ortho-para splitting of the ground state was derived.     

Spectrum of the graphene-based planar quantum dot

The dependence of energy levels of the planar narrow-gap semiconductor quantum dot on its radius, energy gap, and potential barrier height was calculated in the two-band approximation. Based on the results obtained, the energy spectrum of the graphene-based planar quantum dot was studied in detail.     

Are there tachyons in extensive air showers?

The results obtained by studying double-front extensive air showers in which more than 107 particles are contained and in which the fronts are separated by a time interval of Δt ∼ 100 ns are presented. Serious difficulties in explaining “delayed” showers are revealed. In this connection, a hypothesis that the “leading” showers are initiated by tachyons produced in the first interaction of primary particles is proposed.