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L. Chikovani

Publications and source records attributed to L. Chikovani.

5 recordsLinked to original sources

Study of ATLAS sensitivity to FCNC top decays

The ATLAS experiment sensitivity to top quark Flavour Changing Neutral Current (FCNC) decays was studied at LHC using ttbar events. While one of the top quarks is expected to follow the dominant Standard Model decay t->bW, the other decays through a FCNC channel, i.e. t-> Z u(c), t-> gamma u(c) or t-> g u(c). Different types of analyses, applied to each FCNC decay mode, were compared. The FCNC branching ratio sensitivity (assuming a 5sigma signal significance) and 95% confidence level limits on the branching ratios (in the hypothesis of signal absence) were obtained.

hep-ex

The Flavour-Changing Neutral Currents Decay t-->Hq at ATLAS Experiment

The sensitivity of the ATLAS experiment to the top-quark rare decay via flavour-changing neutral currents t --> Hq (q represents c and u quarks) has been studied at sqrt{s} = 14 TeV in the decay mode of ttbar --> HqWb --> WW*q,Wb -->l νl νj, l^{\pm} νb, (l=e, μ). The Standard Model backgrounds ttbar, ttbar H, WZ and WH have been analysed. The signal and backgrounds were generated via PYTHIA 5.7 and simulated and analysed using ATLFAST 2.51. A branching ratio for t --> Hq -->WW*q as low as 2.0x10^{-3} for m_H=150 GeV and 2.1x10^{-3} for m_H=160 GeV could be discovered at the 5 σlevel with an integrated luminosity of 100 fb^{-1}.

hep-ex

Study of ATLAS Sensitivity to FCNC TOP Quark Decay t--> Zq

The sensitivity of ATLAS experiment to the top-quark rare decay via flavor- changing neutral currents t \to Zq (q represents c and u quarks) have been studied at \sqrt{s}= 14 TeV in two decay modes: 1. The pure leptonic decay of gauge bosons: t\bar{t} \to ZqWb \to l^{+} l^{-} j l^{+-} nu j_{b} (l=e, mu) 2. The leptonic decay of Z bosons and hadronic decay of W bosons t\bar{t} \to ZqWb \to l^{+} l^{-} jjjj_{b} (l=e, mu) The dominant backgrounds Z-jets, Zw and t\bar{t} has been analysed. The signal and backgrounds were generated via PYTHIA 5.7, simulated and analysed using ATLFAST 2.14. A branching ratio for t \to Zq as low as 1.1x1-^{4} for the leptonic mode and 2.3x10^{4} for hadronic mode could be discovered at the 5σlevel with an integrated luminosity of 10^{5} pb^{-1}.

hep-ex

A-Dependencies of Neutral Strange Particle Yields at $40 GeV/c \bar p$-Nuclei Collisions

The interactions of $\bar p$ with D(2), Li(7), C(12), S(32), Cu(64) and Pb(207) nuclei at $40 GeV/c$ were studied by RISC-streamer chamber spectrometer. The yields of $K^0$ mesons and $Λ$ and $\barΛ$ hyperons as functions of the target nucleus mass numbers are investigated. The experimental results are compared with model predictions using $FRITIOF-7.02$ program package.

hep-ex