47 research outputs found
Oscillations of neutrinos produced and detected in crystals
No full textWe analyze neutrino oscillations in a thought experiment in which neutrinos are produced by electrons on target nuclei. The neutrinos are detected through charged lepton production in their collision with nuclei in detector. Both the target and the detector are assumed to be crystals. The neutrinos are described by propagators. We find that different neutrino mass eigenstates have equal energies.
We reproduce the standard phase of oscillations and demonstrate that at large distance from the production point oscillations disappear
Neutrino wave function and oscillation suppression
No full textWe consider a thought experiment, in which a neutrino is produced by an electron on a nucleus in a crystal. The wave function of the oscillating neutrino is calculated assuming that the electron is described by a wave packet. If the electron is relativistic and the spatial size of its wave packet is much larger than the size of the crystal cell, then the wave packet of the produced neutrino has essentially the same size as the wave packet of the electron. We investigate the suppression of neutrino oscillations at large distances caused by two mechanisms: 1) spatial separation of wave packets corresponding to different neutrino masses; 2) neutrino energy dispersion for given neutrino mass eigenstates. We resolve contributions of these two mechanisms
Search for narrow dibaryon resonances in neutral pion photoproduction from the deuteron
No full textThe reaction gammad -< pi X-0 has been measured with TAPS at MAMI in the energy range E-gamma = 140-300 MeV. Using the Glasgow tagging spectrometer a photon energy resolution of 0.8 MeV was achieved. The energy excitation functions of integral and differential total cross-sections show no structures of statistical significance < 2 sigma. Upper limits for the production of narrow isoscalar or isovector dibaryons with masses m less than or equal to 2100 MeV/c(2) were deduced. They are in the range 2-5 mub averaged over the 0.8 MeV energy resolution
Charge “asymmetry” from the isospin symmetry in
No full textCharge “asymmetry” meant as is easy to reproduce by the simple-minded reaction mechanism, which stems on the interference of and excited in one of the colliding protons. High-quality experimental data for the reaction taken at CELSIUS storage ring with the PROMICE/WASA detector can be described by the Lorentz-invariant phenomenological approach. The same approach is applied for the description of the asymmetry between and invariant-mass spectra
IR spectroscopic study of the <tex>HCl\cdots O_{3}$</tex> molecular complex in liquid argon
No full textAbstract: Infrared spectra are reported of ozone and HCl dissolved in liquid argon (86-134 K) at concentrations varying from 5 x 10(-5) to 9 x 10(-6) M for HCl, and from 1 x 10(-3) to 5 x 10(-5) M for ozone. At low concentrations of O-3 and of HCl, no spectral features due to O-3-HCl complex were found. At higher concentrations (1 x 10(-3) of ozone vs 5 x 10(-5)-9 x 10(-6) of HCl), a new band near 2840 cm(-1) due to the HCl center dot center dot center dot O-3 complex was observed. FWHM of nu(HCl) of the complex is 8 cm(-1). From the temperature dependence of the absorption band intensity, the enthalpy of the complex formation was estimated, Delta H degrees = 4.7 +/- 0.4 kJ mole(-1). The optimized geometry of the cis-HCl center dot center dot center dot O-3 complex and a value of 6.3 kJ mole(-1) for its binding energy were determined by ab initio calculations. Crown Copyright (C) 2013 Published by Elsevier B.V. All rights reserved
The He-4(pi+,pi-) reaction at low energies
No full textUsing the CHAOS spectrometer at TRIUMF the total cross sections and outgoing pion momentum distributions for the 4He(π+,π−) reaction were measured for π+ kinetic energies from 70 to 130 MeV. At energies around 100 MeV the total cross sections show an excess by a factor 3 over conventional model calculations which could be ascribed to a contribution from a hypothetical d′ dibaryon
