Articolele autorului Mircea Pentia
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Evidence for pi K atoms with DIRAC

We present evidence for the first observation of electromagnetically bound pi^+/- K^-/+ pairs (piK-atoms) with the DIRAC experiment at the CERN-PS. The piK-atoms are produced by the 24 GeV/c proton beam in a thin Pt-target and the pi^+/- and K^-/+ mesons from the atom dissociation are analyzed in a two-arm magnetic spectrometer. The observed enhancement at low relative momentum corresponds to the production of 173+/-54 piK-atoms. The mean life of

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The C-4_F-10 Cherenkov detector for DIRAC-II

A new threshold Cherenkov detector using C4F10 gas radiator was built and put into operation in the DIRAC-II experiment at CERN. Running on the C4F10 at room temperature and atmospheric pressure, the detector discriminates between pions and kaons in the momentum range of 4-8 GeV/c. A compact radiator-gas recirculation system including a gas-liquid separation unit, hollow-fibre membranes and molecular sieves ensures gas purity for a long term of operation

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Preshower detector for pi+ pi- hadronic atom studies

A preshower(PSh) detector has been prepared,tested and used at the CERN-DIRAC experiment. The aim of this experiment was to test some nonperturbative QCD predictions by measuring pionium(pi+pi- hadronic atom)lifetime. In this context the PSh detector,together with the Cherenkov detector, pursued to reject the background electron pairs in the region 1-4GeV where the pion pairs from atom breakup were present. The technique used for pion/electron separation

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Statistical Fluctuations in Nuclear Processes

Fluctuatii in masurari. Erori aleatorii si sistematice. Populatii de date si esantioane din populatii de date. Functii de densitate de probabilitate (Distributii). Analiza datelor. Estimarea parametrilor. Fitare prin metoda celor mai mici patrate. Estimarea corectitudinii unui fit. Fluctuations in measurements. Random and systematic errors. Population and Sample of population data. Probability density functions (Distributions). Data analysis. Parameter

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A Fast Procedure for Geometric Parameter Determination of aSilicon Vertex Tracker

Este prezentata o dependenta analitica a parametrului sigma(vertex), ce masoara dispersia punctelor de vertex obtinute prin reconstructia track-ului de particule in urma imprastierii Coulombiene multiple si a nedeterminarii in masurarea coordonatelor de track, in functie de parametrii geometrici ai unui detector de vertex pe baza de siliciu. An analytical dependence of the sigma(vertex) parameter, measuring the spread of the particle track reconstructed

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DIRAC Experiment and Test of Low-energy QCD

Se face o trecere in revista a prezicerilor QCD la transferuri mici de impuls, ce urmeaza a fi testate cu ajutorul experimentului DIRAC. Sunt prezentate: metoda experimentala precum si caracteristicile si performantele instalatiei experimentale. Analiza preliminara a datelor experimentale indica performante bune ale detectorului: eroarea de aliniere masurata cu ajutorul masei hiperonului Lambda m_Lambda = 1115.6 MeV/c^2, cu o eroare sigma = 0.92

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