Bringing the LHC and ATLAS to a regional planetarium

An outreach effort has started at Michigan State University to bring particle physics, the Large Hadron Collider, and the ATLAS experiment to a general audience at the Abrams planetarium on the MSU campus. A team of undergraduate students majoring in physics, communications arts & sciences, and journalism are putting together short clips about ATLAS and the LHC to be shown at the planetarium.Comment: 5 pages, 5 figures, presented at the 2011 meeting of the Division of Particles and Fields of the American Physical Societ

Single top-quark production with the ATLAS detector in pp collisions at sqrt(s)=7TeV

The ATLAS experiment at the LHC at CERN has analyzed 2010 and 2011 data looking for electroweak production of single top quarks in the lepton+jets and di-lepton final states. The production cross section for the t-channel process is measured to be 76 +41 -21 pb using 156 pb^-1 of 2011 data. A first limit is set on the Wt associated production process using lepton+jets and di-lepton events. The 95% CL upper limit on the Wt production cross section is 158 pb using 35 pb^-1 of 2010 data.Comment: 4 pages, 7 figures, presented at the 2011 Conference on Physics at the LH

Single top quark production and Vtb at the Tevatron

Single top quark production via the electroweak interaction was observed by the D0 and CDF collaborations at the Tevatron proton-antiproton collider at Fermilab. Multivariate analysis techniques are employed to extract the small single top quark signal. The combined Tevatron cross section is 2.76^+0.58_-0.47 pb. This corresponds to a lower limit on the CKM matrix element |Vtb| of 0.77. Also reported are measurements of the t-channel cross section, the top quark polarization in single top quark events, and limits on gluon-quark flavor-changing neutral currents and W' boson production.Comment: Presented at 22nd Rencontres de Blois on Particle Physics and Cosmolog

Top Cross-Sections and Single Top

This paper summarizes top quark cross-section measurements at the Tevatron and the LHC. Top quark pair production cross-sections have been measured in all decay modes by the ATLAS and CMS collaborations at the LHC and by the CDF and D0 collaborations at the Tevatron. Single top quark production has been observed at both the Tevatron and the LHC. The t-channel and associated Wt production modes have been observed at the LHC and evidence for s-channel production has been reported by the Tevatron collaborations.Comment: Proceedings for PIC 201

Single top-quark production at the Tevatron and the LHC

This paper provides a review of the experimental studies of processes with a single top quark at the Tevatron proton-antiproton collider and the LHC proton-proton collider. Single top-quark production in the t-channel process has been measured at both colliders. The s-channel process has been observed at the Tevatron, and its rate has been also measured at the center-of-mass energy of 8 TeV at the LHC in spite of the comparatively harsher background contamination. LHC data also brought the observation of the associated production of a single top quark with a W boson as well as with a Z boson. The Cabibbo-Kobayashi-Maskawa matrix element |Vtb| is extracted from the single-top-quark production cross sections, and t-channel events are used to measure several properties of the top quark and set constraints on models of physics beyond the Standard Model. Rare final states with a single top quark are searched for, as enhancements in their production rates, if observed, would be clear signs of new physics.Comment: 44 pages, accepted by to Review of Modern Physic

Heavy Flavour Working Group Summary

We review theoretical and phenomenological aspects of heavy flavour production as discussed in the heavy flavour working group of the DIS 2012. Recent theoretical progress includes approximate NNLO calculations for heavy quark structure functions in deep inelastic scattering, the extension of the ACOT heavy flavour scheme to jet production, and advances in top physics where the highlight is clearly the first complete NNLO QCD prediction for top pair production in the $q \bar{q}$ annihilation channel. Furthermore, state of the art phenomenological predictions for open charm and bottom, charmonium, and single top and top pair production are discussed in addition to other topics such as the effect of double parton scattering on heavy quark production. New measurements on charm and beauty production presented in the heavy flavor working group are summarized and discussed in comparison with QCD predictions. Top quark strong and weak couplings as well as top quark properties are being measured with precision at the LHC and the Tevatron. We summarize also recent results on spectroscopy of charmonia, bottomonia and $b$-hadrons, along with studies of their decays and properties. Searches for physics beyond Standard Model through precise measurements of rare decays of heavy flavours are discussed as well.Comment: 16 pages, 5 figures, to be published in the Proceedings of the XX International Workshop on Deep Inelastic Scattering, University of Bonn, 26-30th March 201

Next-to-Leading Order Corrections to Single Top Quark Production and Decay at the Tevatron: 1. s-channel Process

We present a study of s-channel single top quark production at the upgraded Tevatron $p\bar{p}$ collider, including the next-to-leading order (NLO) QCD corrections to the production and the decay of the top quark. The "modified" narrow width approximation was adopted to preserve the spin of the top quark in its production and decay. We discuss the effect of the different $O(\alpha_s)$ contributions on the inclusive cross section as well as various kinematic distributions after imposing the relevant cuts to select s-channel single top signal events. In particular the $O(\alpha_s)$ decay contribution, while small in size, has a significant impact on several distributions. With the help of the best-jet algorithm to reconstruct the top quark we demonstrate that it is possible to study kinematical and spin correlations in s-channel single top events. We furthermore compare top quark spin measurements in two different basis and show how NLO corrections have to be taken into consideration in searches for the Higgs boson through $W^{\pm}H$ associated production at the Tevatron.Comment: 39 pages, 37 figure