A first measurement of the inelastic cross-section is presented for proton-proton collisions at a center of mass energy sqrt{s}=7 TeV using the ATLAS detector at the Large Hadron Collider. In a dataset corresponding to an integrated luminosity of 20 mub-1, events are selected by requiring hits on scintillation counters mounted in the forward region of the detector. An inelastic cross-section of $60.3 +/- 2.1 mb is measured for xi > 5x10^-6, where xi=M_X^2/s is calculated from the invariant mass, M_X, of hadrons selected using the largest rapidity gap in the event. For diffractive events this corresponds to requiring at least one of the dissociation masses to be larger than 15.7 GeV.
The measured and extrapolated inelastic cross section. The first error is the experimental error and the second (sys) error is the error in the extrapolation.
Results are presented of a search for supersymmetric particles in events with large missing transverse momentum and at least one heavy flavour jet candidate in sqrt{s} = 7 TeV proton-proton collisions. In a data sample corresponding to an integrated luminosity of 35 pb-1 recorded by the ATLAS experiment at the Large Hadron Collider, no significant excess is observed with respect to the prediction for Standard Model processes. For R-parity conserving models in which sbottoms (stops) are the only squarks to appear in the gluino decay cascade, gluino masses below 590 GeV (520 GeV) are excluded at the 95% C.L. The results are also interpreted in an MSUGRA/CMSSM supersymmetry breaking scenario with tan(beta)=40 and in an SO(10) model framework.
Distribution of the effective mass for data and the SM expectation in the zero-lepton plus 3 jet channel.
Distribution of the missing ET for data and the SM expectation in the zero-lepton plus 3 jet channel.
Distribution of the effective mass for data and the SM expectation in the one-lepton plus 2 jet channel.
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