Seach For Second Generation Leptoquarks In Proton Anti Proton Collisions

Seach for Second - Generation Leptoquarks in Proton - Anti-proton Collisions

This document describes the search for second-generation leptoquarks (LQ{sub 2}) in around 114pb{sup -1} of p{bar p} collisions, recorded with the D0 detector between September 2002 and June 2003 at a centre-of-mass energy of {radical}s = 1.96TeV. The predictions of the Standard Model and models including scalar leptoquark production are compared to the data for various kinematic distributions. Since no excess of data over the Standard Model prediction has been observed, a lower limit on the leptoquark mass of M{sub LQ{sub 2}}{sup {beta}=1}> 200GeV has been calculated at 95% confidence level (C.L.), assuming a branching fraction of {beta} = BF(LQ{sub 2} {yields} {mu}j) = 100% into a charged lepton and a quark. The corresponding limit for {beta} = 1/2 is M{sub LQ{sub 2}}{sup {beta}=1/2}> 152 GeV. Finally, the results were combined with those from the search in the same channel at D0 Run I. This combination yields the exclusion limit of M{sub LQ{sub 2}}{sup {beta}=1}> 222 GeV (177GeV) for (beta) = 1 (1/2) at 95% C.L., which is the best exclusion limit for scalar second-generation leptoquarks (for {beta} = 1) from a single experiment to date.

The Evidence for the Top Quark

The Evidence for the Top Quark offers both a historical and philosophical perspective on an important recent discovery in particle physics: the first evidence for the elementary particle known as the top quark. Drawing on published reports, oral histories, and internal documents from the large collaboration that performed the experiment, Kent Staley explores in detail the controversies and politics that surrounded this major scientific result.At the same time the book seeks to defend an objective theory of scientific evidence based on error probabilities.

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