Multi Jet Analysis For The Top Search At The Fermilab Collider

'Dorigo provides an engaging and insightful perspective on the pursuit of physics discoveries at CDF … Dorigo’s book is thus almost certainly going to be an important source for anyone interested in the history of CDF … It is a personal yet highly informative story of discovery and almost-discovery from the perspective of someone who saw the events firsthand.'Physics TodayFrom the mid-1980s, an international collaboration of 600 physicists embarked on the investigation of subnuclear physics at the high-energy frontier. As well as discovering the top quark, the heaviest elementary particle ever observed, the physicists analyzed their data to seek signals of new physics which could revolutionize our understanding of nature.Anomaly! tells the story of that quest, and focuses specifically on the finding of several unexplained effects which were unearthed in the process. These anomalies proved highly controversial within the large team: to some collaborators they called for immediate publication, while to others their divulgation threatened to jeopardize the reputation of the experiment.Written in a confidential, narrative style, this book looks at the sociology of a large scientific collaboration, providing insight in the relationships between top physicists at the turn of the millennium. The stories offer an insider's view of the life cycle of the 'failed' discoveries that unavoidably accompany even the greatest endeavors in modern particle physics.

We performed a search for"non-standard model tt resonances in the all jets final state channel." The main goal was to examine top-antitop invariant mass spectrum for the presence of narrow resonant states. The data analysis used 2.8fb-1 of CDF data; events were produced at the Tevatron collider in pp collisions with center-of-mass energy of 1.96 TeV. 2086 data events were analyzed and compared to Standard Model expectation. No evidence for new tt resonant production mechanisms was found. Upper limits were placed on the cross-section times branching ratio for resonance production at 805 GeV/c2. For signal modeling we considered leptophobic Z' boson in a topcolor-assisted technicolor model with the width of [Gamma] = 1.2%MX0.

ABSTRACT: We performed a search for"non-standard model tṫ resonances in the all jets final state channel." The main goal was to examine top-antitop invariant mass spectrum for the presence of narrow resonant states. The data analysis used 2.8fb−1 of CDF data; events were produced at the Tevatron collider in p[bar p] collisions with center-of-mass energy of 1.96 TeV. 2086 data events were analyzed and compared to Standard Model expectation. No evidence for new tṫ resonant production mechanisms was found. Upper limits were placed on the cross-section times branching ratio for resonance production at 805 GeV/c2. For signal modeling we considered leptophobic Z' boson in a topcolor-assisted technicolor model with the width of [capital gamma]= 1.2%MX0.

In the scope of the strong ongoing data analysis efforts of the CDF col- laboration at Fermilab, we present a search for the production of mas sive W1 bosons decaying to a top and a bottom quark in p$\bar{p}$ collisions at √s = 1.96 TeV. To perform this search, we select events with large Missing Transverse Energy plus two or three jets, in which the W generated from top decays leptonically, and either the e or μ is lost or the [tau] is reconstructed as a jet. A complete study of the selected sample is discussed, including the creation and subsequent optimization of a Neural Network-based multivariate tool to reject the QCD multijet background from the signal region. Finally, we perform a likelihood-based multichannel Bayesian fit procedure on the invariant transverse mass of the Missing Transverse Energy and jets to extract 95% CL limits on [sigma](p$\bar{p}$ . → W') × B(W' → tb) for MW' = 200 GeV/c2.