J. Pilot

Jet substructure has emerged to play a central role at the Large Hadron Collider, where it has provided numerous innovative ways to search for new physics and to probe the Standard Model, particularly in extreme regions of phase space. In this article we focus on a review of the development and use of state-of-the-art jet substructure techniques by the ATLAS and CMS experiments.

This report of the BOOST2012 workshop presents the results of four working groups that studied key aspects of jet substructure. We discuss the potential of first-principle QCD calculations to yield a precise description of the substructure of jets and study the accuracy of state-of-the-art Monte Carlo tools. Limitations of the experiments' ability to resolve substructure are evaluated, with a focus on the impact of additional (pile-up) proton proton collisions on jet substructure performance in future LHC operating scenarios. A final section summarizes the lessons learnt from jet substructure analyses in searches for new physics in the production of boosted top quarks.

This report summarizes the work of the Energy Frontier Top Quark working group of the 2013 Community Summer Study (Snowmass).

At the Large Hadron Collider, numerous physics processes expected within the standard model and theories beyond it give rise to very-high-momentum particles decaying to multihadronic final states. Development of algorithms for efficient identification of such ``boosted'' particles while rejecting the background from multihadron jets from light quarks and gluons can greatly aid in the sensitivity of measurements and new particle searches. This paper presents a new method for identifying boosted high-mass particles using event shapes in Lorentz-boosted reference frames. Variables calculated in these frames for multihadronic jets can then be used as input to a large artificial neural network to discriminate their origin.

The increased center-of-mass energy of proton-proton collisions at the LHC allows for higher and higher mass scales to be probed in the search for new physics. These searches for new physics can often involve the reconstruction of top quark decays. In this high-mass regime, event topologies can change and top quark decay products become highly boosted, requiring the use of special identification algorithms. This report summarizes the latest techniques used in the reconstruction of boosted top quarks, and highlights several new physics searches from ATLAS and CMS where they are utilized. Such analyses include the search for top quark pair resonances as is expected from Z’ decays, as well as top quark partner searches, such as fourth generation vector-like quarks, excited top quarks, and top quark partners with non-standard charges

This report describes the studies performed for the Snowmass "Top algorithms and detectors" High Energy Frontier Study Group.

The CMS detector currently includes three different muon detector types: drift tubes (DT) in the central region, cathode strip chambers (CSC) in the forward regions, and resistive plate chambers (RPC) in both the forward and central regions. Several upgrade projects are planned to maintain high data-taking efficiency with the planned running conditions for the high-luminosity upgrade of the LHC. These upgrades are designed to ensure detector longevity and increase redundancy, while mitigating rate increases and retaining sensitivity to phyics processes. This involves changes to electronics and infrastructure of existing detectors, and adding new detectors in the forward region of the CMS experiment. Plans for each of the muon subsystems are described here in the context of the Phase-II upgrade schedule of the CMS experiment.

We present a search for the Standard Model Higgs Boson using the process $ZH\to\mu^+\mu^- b\bar{b}$. We use a dataset corresponding to 9.2 fb$^{-1}$ of integrated luminosity from proton-antiproton collisions with center-of-mass energy 1.96 TeV at the Fermilab Tevatron, collected with the CDF II detector. This analysis benefits from several new multivariate techniques that have not been used in previous analyses at CDF. We use a multivariate function to select muon candidates, increasing signal acceptance while simultaneously keeping fake rates small. We employ an inclusive trigger selection to further increase acceptance. To enhance signal discrimination, we utilize a multi-layer approach consisting of expert discriminants. This multi-layer discriminant method helps isolate the two main classes of background events, $t\bar{t}$ and $Z$+jets production. It also includes a flavor separator, to distinguish light flavor jets from jets consistent with the decay of a $B$-hadron. Wit h this novel multi-layer approach, we proceed to set limits on the $ZH$ production cross section times branching ratio. For a Higgs boson with mass 115 GeV/$c^2$, we observe (expect) a limit of 8.0 (4.9) times the Standard Model prediction.

The CMS detector currently includes three different muon detector types: drift tubes (DT) in the central region, cathode strip chambers (CSC) in the forward regions, and resistive plate chambers (RPC) in both the forward and central regions.Several upgrade projects are planned to maintain high data-taking efficiency with the planned running conditions for the high-luminosity upgrade of the LHC.These upgrades are designed to ensure detector longevity and increase redundancy, while mitigating rate increases and retaining sensitivity to phyics processes.This involves changes to electronics and infrastructure of existing detectors, and adding new detectors in the forward region of the CMS experiment.Plans for each of the muon subsystems are described here in the context of the Phase-II upgrade schedule of the CMS experiment.

This contribution details results of recently completed searches for massive vector-like top and bottom quark partners using proton-proton collision data collected with the CMS detector at the CERN LHC at a center-of-mass energy of 13 TeV. Single and pair production of vector-like quarks are studied, with decays into a variety of final states, containing top and bottom quarks, electroweak gauge and Higgs bosons. Analyses utilize several categories of reconstructed objects, from multi-leptonic to fully hadronic final states. Improved exclusion limits on both the vector-like quark mass and cross sections are obtained, for combinations of the possible vector-like quark branching ratios.

The New Hampshire state police are using portable videotape units for apprehension and conviction of traffic violators. Acceptable proof is recorded for tailgating (close following), driving too slowly, driving under the influence, and other violations. The role of videotape in highway safety is briefly discussed. KEYWORDS: Drunk driving; Highway safety; Police; Portable equipment; Slow moving vehicles; Tailings; Television; Traffic violators; Close following Language: en