Improving Higgs Sensitivity at CDF by Introducing New Muon Triggers

Buchmann, Marco-Andrea

Fermi National Accelerator Laboratory

关键词: Probability;    Decay;    43 Particle Accelerators;    Sensitivity;    Matrix Elements;   

DOI  :  10.2172/1027474
RP-ID  :  FERMILAB-MASTERS-2010-05
RP-ID  :  AC02-07CH11359
RP-ID  :  1027474

美国|英语

来源: UNT Digital Library

【 摘 要 】

A search for Standard Model Higgs boson production in the H {yields} WW {yields} {ell}{nu}jj channel using 5.7 fb{sup -1} of CDF II data is presented. The search is performed using a matrix element technique in which event probability densities for the signal and background hypotheses are calculated and used to create a powerful disciminator (called the event probability discriminant, EPD). The EPD distributions for signal and background are fit to the data using a binned likelihood approach to search for the Higgs boson signal. To improve the limits on the H production cross section, a new muon category, CMP, is added. No evidence for a Higgs boson signal is observed, and 95% confidence level upper limits on the H cross section times the branching ratio of the Higgs boson to decay to two W of {sigma}(p{bar p} {yields} H) x BR(H {yields} WW)/SM < 7.7 to 62.1 for Higgs boson masses of between m{sub H} = 150 GeV/c{sup 2} and m{sub H} = 200 GeV/c{sup 2} are found. The expected (median) limit estimated in pseudo-experiments is {sigma}(p{bar p} {yields} H) x BR(H {yields} WW)/SM < 12.5 to 41.0 at 95% C.L. The inclusion of the phi gap trigger lead to improvements in the sensitivity of up to 7.3%; on average, the improvement in the sensitivity was 3.3%.