arXiv subjects
Publications and source records attributed to S. A. Sadovsky.
The results of measurements of the characteristics of photodetectors based on large-area SiPM matrices with a wide dynamic range are presented. The potential application of SiPM-based photodetectors for electromagnetic calorimetry in the energy range from hundreds of keV to tens of GeV is explored. The potential application of SiPM in gamma-spectroscopy is also discussed.
The method to calculate the non-linearity correction of the electromagnetic calorimeter response, based on minimisation of the deviation of the measured neutral meson mass on the energies of it decay photons, is described in this paper. This method was developed for the electromagnetic calorimeter LGD2 in the Hyperon-M experiment at U70 accelerator of IHEP. The found correction allowed to reduce significantly variations of the reconstructed $π^0$ and $η$ masses on the minimal energy of the mesons.
A neural network method is developed to discriminate direct photons from the neutral pion background in the PHOS spectrometer of the ALICE experiment at the LHC collider. The neural net has been trained to distinguish different classes of events by analyzing the energy-profile tensor of a cluster in its eigen vector coordinate system. Monte-Carlo simulations show that this method diminishes by an order of magnitude the probability of $π^0$-meson misidentification as a photon with respect to the direct photon identification efficiency in the energy range up to 120 GeV.
We discuss the phenomenological model of Centauro event production in relativistic nucleus-nucleus collisions. This model makes quantitative predictions for kinematic observables, baryon number and mass of the Centauro fireball and its decay products. Centauros decay mainly to nucleons, strange hyperons and possibly strangelets. Simulations of Centauro events for the CASTOR detector in Pb-Pb collisions at LHC energies are performed. The signatures of these events are discussed in detail.
We describe the CASTOR detector designed to probe the very forward, baryon-rich rapidity region in nucleus-nucleus collisions at the LHC. We present a phenomenological model describing the formation of a QGP fireball in a high baryochemical potential environment, and its subsequent decay into baryons and strangelets. The model explains Centauros and the long-penetrating component and makes predictions for the LHC. Simulations of Centauro-type events were done. To study the response of the apparatus to new effects different exotic species (DCC, Centauros, strangelets etc.) were passed through the deep calorimeter. The energy deposition pattern in the calorimeter appears to be a new clear signature of the QGP.
We present a phenomenological model which describes the formation of a Centauro fireball in nucleus-nucleus interactions in the upper atmosphere and at the LHC, and its decay to non-strange baryons and Strangelets. We describe the CASTOR detector for the ALICE experiment at the LHC. CASTOR will probe, in an event-by-event mode, the very forward, baryon-rich phase space 5.6 < η< 7.2 in 5.5 A TeV central Pb + Pb collisions. We present results of simulations for the response of the CASTOR calorimeter, and in particular to the traversal of Strangelets.
The physics motivation for a very forward detector for the ALICE heavy ion experiment at the CERN LHC is discussed. A phenomenological model describing the formation and decay of a Centauro fireball in nucleus-nucleus collisions is presented. The CASTOR detector which is aimed to measure the hadronic and photonic content of an interaction and to identify deeply penetrating objects in the very forward, baryon-rich phase space 5.6 < eta < 7.2 in an event-by-event mode is described. Results of simulations of the expected response of the calorimeter, and in particular to the passage of strangelets, are presented.
The reaction $π^-p \to ηπ^o n$ has been studied with GAMS-2000 spectrometer in the secondary 38 GeV/c $π^-$-beam of the IHEP U-70 accelerator. Partial wave analysis of the reaction has been performed in the $ηπ^o$ mass range up to 1200 MeV. The $a_0(980)$-meson is seen as a sharp peak in S-wave. The $t$-dependence of $a_0(980)$ production cross section has been studied. Dominant production of the $a_0(980)$ at a small transfer momentum $t$ confirms the hypothesis of Achasov and Shestakov about significant contribution of the $ρ_2$ exchange ($I^GJ^{PC}=1^+2^{--}$) in the mechanism of $a_0(980)$ meson production in $t$-channel of the reaction.
We perform the K-matrix analysis of meson partial waves with IJ^{PC} =00^{++}, 10^{++}, 02^{++}, 12^{++} basing on GAMS data on π^-p -> π^0π^0 n, ηηn, ηη' n together with BNL data on π^-p -> K\bar K n and Crystal Barrel data on p\bar p (at rest) -> π^0π^0π^0, π^0ηη, π^0π^0η. The positions of the amplitude poles (physical resonances) are determined as well as the positions of the K-matrix poles (bare states) and the values of bare state couplings to two-meson channels. Nonet classification of the determined bare states is discussed.