A. Voronin

Observation of a narrow baryon resonance decaying to pK S 0 in proton-nucleus interactions at 70 GeV/c with the SVD-2 setup

AbstractData from the SVD-2 experiment that were obtained at the IHEP accelerator in 70-GeV/c proton-nucleus interactions are analyzed with the aim of searches for an exotic Θ+ baryon that decays through the pKS0 channel. The reaction pN → pKS0 + X characterized by a bounded multiplicity of charged secondaries is used for this analysis. A resonance of mass M = 1526 ± 3(stat.) ± 3(syst.) MeV/c2 and width Γ < 24 MeV/c2 is observed in the invariant-mass spectrum of the pKS0 system at a statistical significance of 5.6σ. The mass and the width of this resonance correspond to the recently found positive-strangeness Θ+ baryon, which was predicted to be an exotic baryon consisting of five quarks (pentaquark),

Spectrometer with a vertex detector for experiments at the IHEP accelerator

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A study of the coordinate gas-filled detectors based on the GEM and TGEM technologies for the muon tracking system of the CBM experiment

. The total cross section for the production of a Θ+ baryon in pA interactions is estimated at a value within the range 30–120 μb for xF ≥ 0. An analysis of the A dependence of the cross section for Θ+-baryon production does not reveal a significant deviation from the A dependence for inelastic events (∼A0.7).

Testing a 32-channel integrated circuit for recording signals of silicon detectors

A front-end ASIC for GEM detectors readout in the CBM experiment is presented. The design has the following features: dynamic range of 100 fC, channel hit rate of 2 MHz, ENC of 1000 e- at 50 pF, power comsumption of 10 mW per channel, 6 bit SAR ADC. The chip includes 8 analog processing chains, each consisting of preamplifier, two shapers (fast and slow), differential comparator and an area efficient 6 bit SAR ADC with 1.2 mW power consunption at 50 Msps. The chip also includes the threshold DAC and the digital part.

Testing the prototype of the NUCLEON setup on the pion beam of the SPS accelerator (CERN)

The stages of development and the current status of the versatile “Spectrometer with a Vertex Detector” setup designed for physics experiments at the U-70 accelerator of the Institute for High Energy Physics (Protvino) is described. The main detectors of the setup are the vertex detector based on silicon microstrip detectors, the wide-aperture magnetic spectrometer based on multiwire proportional chambers, and the lead-glass hodoscope γ detector. In the setup, there is a fast two-level trigger system for selecting required particle interactions. The key characteristics of the setup systems are presented, and the physical results obtained on it are briefly listed.

The NUCLEON experiment: The current status

While preparing for the NUCLEON experiment, a prototype of the experimental setup was tested on a beam of high-energy ions. The response of the charge-measuring system was investigated. The test experiment was simulated. The simulated charge distributions were compared to the experimental data.

Development and experimental study of the readout ASIC for muon chambers of the CBM experiment

Prototypes of the gas-filled detectors based on the GEM and TGEM technologies have been studied in the multistage gas amplification circuit with the aim of selecting variants for tracking detectors of the muon system capable of operating at high counting rates in the CBM experiment. Two- and three-component mixtures based on Ar and He are used as the working gas. Their key characteristics are presented. The gas amplification factors are measured for various high-voltage modes. The charge collection times determining the response speed of the tested detectors are estimated.

Read-out ASIC for microstrip detectors

A 32-channel integrated microcircuit for microstrip silicon detectors of the “Nuklon” project for studying ionizing radiation in space conditions is tested. The microcircuit allows one to record signals of relativistic particles and nuclei with a charge from Z = 1 up to Z > 50 from silicon detectors. A structural diagram of the microcircuit and its main experimental characteristics are given. The power consumption does not exceed 1.5 mW/channel, and the dynamic range of recorded signals is not smaller than 100 pC.