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M. Mosidze

Publications and source records attributed to M. Mosidze.

2 recordsLinked to original sources

Study of the Radiation Hardness of the ATLAS Tile Calorimeter Optical Instrumentation with Run 2 data

This paper presents a study of the radiation hardness of the hadronic Tile Calorimeter of the ATLAS experiment in the LHC Run 2. Both the plastic scintillators constituting the detector active media and the wavelength-shifting optical fibres collecting the scintillation light into the photodetector readout are elements susceptible to radiation damage. The dedicated calibration and monitoring systems of the detector (caesium radioactive sources, laser and minimum bias integrator) allow to assess the response of these optical components. Data collected with these systems between 2015 and 2018 are analysed to measure the degradation of the optical instrumentation across Run 2. Moreover, a simulation of the total ionising dose in the calorimeter is employed to study and model the degradation profile as a function of the exposure conditions, both integrated dose and dose rate. The measurement of the relative light output loss in Run 2 is presented and extrapolations to future scenarios are drawn based on current data. The impact of radiation damage on the cell response uniformity is also analysed.

physics.ins-det

The comparison of characteristics of pi^{-} mesons produced in central Mg-Mg interactions with the quark gluon string model predictions

A detailed study of pion production in central Mg-Mg collisions at a momentum of 4.3 GeV/c per incident nucleon was carried out with use of the setup GIBS. The average kinematical characteristics of pions (multiplicity n_, momentum P, transverse momentum P_{T}, emission angle Q, rapidity Y) and corresponding distributions have been obtained. The experimental results have been compared with the predictions of the Quark Gluon String Model (QGSM) and satisfactory agreement between the experimental data and the model has been found. The QGSM reproduces also the dependence of average P_{T} on n_{-}. The temperatures of pi^{-} mesons have been estimated in the rapidity interval of 0.5<=Y<=2.1. A satisfactory fit for pi^{-} mesons has been achieved by using a form involving two temperatures T_{1} and T_{2}. It was found that the QGSM underestimates T_{2} by (10-15)%. The data have been analyzed using the transverse momentum technique. The observed dependence of the on Y shows the S-shape behaviour. The slope at midrapidity F had been determined. The QGSM reproduces the distribution satisfactorily, but underestimates the parameter F.

hep-ex