C. Calancha

Operational experience, improvements, and performance of the CDF Run II silicon vertex detector

The Collider Detector at Fermilab (CDF) pursues a broad physics program at Fermilabs Tevatron collider. Between Run II commissioning in early 2001 and the end of operations in September 2011, the Tevatron delivered 12 fb-1 of integrated luminosity of pp collisions at s=1.96TeV. The physics at CDF includes precise measurements of the masses of the top quark and W boson, measurement of CP violation and Bs mixing, and searches for Higgs bosons and new physics signatures, all of which require heavy flavor tagging with large charged particle tracking acceptance. To realize these goals, in 2001 CDF installed eight layers of silicon microstrip detectors around its interaction region. These detectors were designed for 2-5 years of operation, radiation doses up to 2 Mrad (0.02 Gy), and were expected to be replaced in 2004. The sensors were not replaced, and the Tevatron run was extended for several years beyond its design, exposing the sensors and electronics to much higher radiation doses than anticipated. In this paper we describe the operational challenges encountered over the past 10 years of running the CDF silicon detectors, the preventive measures undertaken, and the improvements made along the way to ensure their optimal performance for collecting high quality physics data. In addition, we describe the quantities and methods used to monitor radiation damage in the sensors for optimal performance and summarize the detector performance quantities important to CDFs physics program, including vertex resolution, heavy flavor tagging, and silicon vertex trigger performance.

Improved determination of the sample composition of dimuon events produced in pp̄ collisions at √s=1.96 TeV - eScholarship

We use a new method to estimate with 5% accuracy the contribution of pion and kaon in-flight-decays to the dimuon data set acquired with the CDF detector. Based on this improved estimate, we show that the total number and the properties of the collected dimuon events are not yet accounted for by ordinary sources of dimuons which also include the contributions, as measured in the data, of heavy flavor, ϒ, and Drell–Yan production in addition to muons mimicked by hadronic punchthrough. The number of unaccounted events corresponds to (12.8±3.2)% of the

Search for narrow resonances lighter than Υ mesons - eScholarship

b\bar{b}

Limits on Anomalous Trilinear Gauge Couplings in Z

production. We find that (23±6)% of the unaccounted events contain additional muon candidates. For comparison, this fraction is (6.9±0.4)% for events due to

Search for Heavy Bottomlike Quarks Decaying to an Electron or Muon

b\bar{b}

Evidence for t tproduction and measurement oft t = t t

production.