arXiv subjects

T. A. Dzhatdoev

Publications and source records attributed to T. A. Dzhatdoev.

21 records · Page 2Linked to original sources

arXiv2014

Search for Neutrino Oscillations in Appearance Mode with the OPERA Experiment

The present paper highlights the data analysis status of the OPERA experiment. The experiment was designed to perform the neutrino interactions analysis on event-by-event basis, and optimized to search for $ν_μ \rightarrow ν_τ$ oscillation in appearance mode, also allowing to perform a $ν_{e}$ appearance search. We review the data simulation and the analysis chains implemented to search for $ν_τ$ interactions. The main kinematical parameters sensitive to the neutrino flavor are discussed, the uncertainties of the event parameter estimation are reviewed, and the main sources of background for the $ν_μ \rightarrow ν_τ$ oscillation search are examined. The topologies of the two first $ν_τ$ candidate events are presented. Finally, we review the status of the $ν_{e}$ appearance search and present the constraints set by the OPERA experiment on the mixing angle $θ_{13}$ and on the LSND/MiniBooNE anomaly.

hep-ex↗

arXiv2012

Results on the primary CR spectrum and composition reconstructed with the SPHERE-2 detector

First preliminary results of the balloon-borne experiment SPHERE-2 on the all-nuclei primary cosmic rays (PCR) spectrum and primary composition are presented. The primary spectrum in the energy range $10^{16}$--$5\cdot10^{17}$ eV was reconstructed using characteristics of Vavilov-Cherenkov radiation of extensive air showers (EAS), reflected from a snow surface. Several sources of systematic uncertainties of the spectrum were analysed. A method for separation of the primary nuclei' groups based on the lateral distribution function' (LDF) steepness parameter is presented. Preliminary estimate of the mean light nuclei' fraction $f_{30-150}$ at energies $3\cdot10^{16}$--$1.5\cdot10^{17}$ eV was performed and yielded $f_{30-150}$= (21$\pm$11)%.

astro-ph.HE↗

arXiv2012

Status of the SPHERE experiment

Here is presented the current state of the SPHERE-2 balloon-borne experiment. The detector is elevated up to 1 km above the snow surface and registers the reflected Vavilov-Cherenkov radiation from extensive air showers. This method has good sensitivity to the mass-composition of the primary cosmic rays due to its high resolution near the shower axis. The detector consists of a 1500 mm spherical mirror with a 109 PMT cluster in its focus. The electronics record a signal pulse profile in each PMT. In the last 2 years the detector was upgraded: time resolution of pulse registration was enhanced up to 12.5 ns, channel sensitivity was increased by a factor of 3, a new LED-based relative PMT calibration method was introduced, and new hardware and etc. was installed.

astro-ph.IM↗