Measurement of the Top Pair Production Cross section at ATLAS

We present the measurement of the production cross section for top quark pair ($t\bar{t}$) in pp collisions at $\sqrt{s}$ = 7 TeV using the data recorded with the ATLAS detector at the Large Hadron Collider (LHC). Events are selected in single lepton (electron or muon) and dilepton ($ee$, $\mu\mu$, $e\mu$) topologies with multi-jets, and large missing transverse energy (MET). The combined result from these measurements is $\sigma_{t\bar{t}}$ = $176 \pm 5 \mathrm{(stat.)} ^{+13}_{-10}\mathrm{(syst.)} \pm 7 \mathrm{(lumi.)} \mathrm{pb}$, which is in good agreement with the Standard Model prediction.Comment: 8 pages, 9 figures, Proceedings of the DPF-2011 Conference, Providence, RI, August 8-13, 201

Study of Inflationary Generalized Cosmic Chaplygin Gas for Standard and Tachyon Scalar Fields

We consider an inflationary universe model in the context of generalized cosmic Chaplygin gas by taking matter field as standard and tachyon scalar fields. We evaluate the corresponding scalar fields and scalar potentials during intermediate and logamediate inflationary regimes by modifying the first Friedmann equation. In each case, we evaluate the number of e-folds, scalar as well as tensor power spectra, scalar spectral index and important observational parameter, i.e., tensor-scalar ratio in terms of inflatons. The graphical behavior of this parameter shows that the model remains incompatible with WMAP7 and Planck observational data in each case.Comment: 20 pages, 8 figures, Accepted for publication in EPJ

QCD analysis of neutrino charged current structure function F2 in deep inelastic scattering

An analytic expression for the neutrino charged current structure function F sub 2 (x, Q sup 2) in deep inelastic scattering, consistent with quantum chromodynamics, is proposed. The calculated results are in good agreement with experiment