118491858
Conformal covariant description of mesons and baryons in composite superconformal string model
Operator nucleon vertices are constructed in composite superconformal string model. Splitting of baryon Regge trajectories with the same quantum numbers but with opposite parity is provided by inclusion of special two-dimensional field to be carried spin-parity quantity on the basic two-dimensional surface. Then conservation of cyclic symmetry of hadron string amplitudes and necessary duality properties requires nucleon vertices with separation of spinor components of different chirality.
124885220
Nonplanar dual model with arbitrary intercept $alpha$(0)
115452072
Production of high-energy muons in extensive air showers from primary el rays
The primary mechanism for the production of high-energy muons (E/sub / > 5 TeV) in extensive air showers from primary el rays is the production of muon pairs by shower photons in the field of a nucleus.
116402726
Superfermionic superconformal string model
119374640
Fermion dominated composite superstring model and unified description of hadron and lepton degrees of freedom in it
New string dynamics is formulated on the basis of the extended set of supergauge constraints including not only supergauge Virasoro conditions but also nilpotent supercurrent constraints . This approach arises from a natural generalization of the classical operator many-string vertices. The formulation of this model leads to three two-dimensional surfaces for description of hadron strings. It gives some dynamical generalization of Chan-Paton factor for string amplitudes in terms of operator vertices. Supersymmetry on the 2-d world surface is present but ten-dimensional supersymmetry is absent. In this approach two-dimensional fermion string fields make it possible to give a unified description of hadron and lepton degrees of freedom and of its dynamics. This model allows to solve the problem of elimination of the most part of parity twins in the baryon spectrum. One-loop (and many-loops perhaps) amplitudes in this model are finite due to the extended set of supergauge constraints and to the significant excess of the total number of fermion two-dimensional fields over the number of boson 2-d fields.
116301993
Quasi-stable states in the physical spectrum of the Neveu-Schwarz dual model
A certain class of states, comprising most of the spectrum for large mass M, is distinguished in the spectum of physical states predicted by the Neveu-Schwarz dual model with intercepts ..cap alpha../sub rho/(0) =1 and ..cap alpha../sub ..pi../(0) =1/2. The massive particles with large spins in this class are quasi-stable. Their couplings with all the other states are of order M/sup -1/ in comparison with the ordinary vertices. For the critical dimensions D=10 these states coincide with the zero-norm spurions. For the anomalous dimensions D=9 some of the quasi-stable states become new zero-norm spurion states. (AIP)
118315137
Background studies for particle astrophysics experiments
Background radiations typical for the high‐sensitivity underground experiments in particle astrophysics are discussed. An emphasis is given to the neutron background coming from spontaneous fission and (α,n) reactions from U and Th traces in rock and detector components, and from cosmic‐ray muons. Gammas from radioactivity in various materials are also considered. Special case of a xenon‐based large‐scale dark matter detector is studied. Several Monte Carlo codes capable of producing, transporting and detecting neutrons are compared with each other and with available experimental data.
125894935
RELATIVISTIC STRING MODEL AND MULTIPLICATIVE DUAL MODEL
3193027
A three-dimensional code for muon propagation through the rock: MUSIC
Abstract We present a new three-dimensional Monte-Carlo code MUSIC (MUon SImulation Code) for muon propagation through the rock. All processes of muon interaction with matter with high energy loss (including the knock-on electron production) are treated as stochastic processes. The angular deviation and lateral displacement of muons due to multiple scattering, as well as bremsstrahlung, pair production and inelastic scattering are taken into account. The code has been applied to obtain the energy distribution and angular and lateral deviations of single muons at different depths underground. The muon multiplicity distributions obtained with MUSIC and CORSIKA (Extensive Air Shower simulation code) are also presented. We discuss the systematic uncertainties of the results due to different muon bremsstrahlung cross-sections.
15110574
Characteristics of alpha, gamma and nuclear recoil pulses from NaI(Tl) at 10–100 keV relevant to dark matter searches
Abstract Measurements of the shapes of scintillation pulses produced by nuclear recoils, alpha particles and photons in NaI(Tl) crystals at visible energies of 10–100 keV have been performed in order to investigate possible sources of background in NaI(Tl) dark matter experiments and, in particular, the possible origin of the anomalous fast time constant events observed in the UK Dark Matter Collaboration experiments at Boulby mine [P.F. Smith et al., Phys. Rep. 307 (1998) 275]. Pulses initiated by X-rays (via photoelectric effect close to the surface of the crystal) were found not to differ from those produced by high-energy photons (via Compton electrons inside the crystal) within experimental errors. However, pulses induced by alpha particles (degraded from an external MeV source) were found to be ∼10% faster than those of nuclear recoils, but insufficiently fast to account for the anomalous events.
117121226
A Dual Model for Fermions Without Parity Degeneracy on the Principal Trajectory