Search for second generation leptoquarks in $\sqrt{s}$ = 1.8-TeV $p^-$ pbar at CDF and silicon detector readout electronics development with ATLAS

Abstract

In this thesis, a search for second generation leptoquark is presented. It is based on the data collected at the Collider Detector at Fermilab with the Tevatron proton-antiproton collisions of $\sqrt{s}$ = 1.8 TeV. A total integrated luminosity of 110 pb-1 collected during runs in 1992-1995 is used. The search was performed on the charged dimuon plus dijet channel. No evidence for existence of leptoquark was found, and a new production cross section limit is set as a result of this analysis. Using the most recent theoretical calculation of pair leptoquark production [1], a new lower mass limit for second generation scalar leptoquark is extracted. The new limit excludes M(LQ2)< 202 GeV/c2. The Large Hadron Collider (LHC), a proton-proton collider with a center of mass energy ($\sqrt{s}$) of 14 TeV, is currently under the construction at CERN. It will be utilised to extend the searches for the leptoquarks to higher mass regions. As in CDF, tracking detectors are essential to identify charged leptons decaying from leptoquarks. A silicon strip tracking detector is being developed for the ATLAS experiment. A dense and fast readout system with a good signal to noise ratio and low power consumption are required with high luminosity and short event collision interval (25 ns) expected at the LHC. A description of a prototype front-end micro-electronic chip, the ADAM, for silicon strip detector readout application is presented. Results from a complete laboratory test as well as its performance on a test beam at CERN are reported.