# The Search for VH → VWW standard model higgs production in the trilepton signature with 5.9fb<sup>-1</sup> of data from p$\bar{p}$ collisions at √s=1.96 GeV

### Description

We present here the search for Standard Model V H → VWW → lll + E<sub>T</sub> (missing energy due to neutrinos) production, where V is a W or Z weak vector boson, which uses up to 5.9 fb<sup>-1</sup> of integrated luminosity. This analysis has recently added to the CDF high-mass Higgs group three new signal topologies characterized by a tri-lepton signature, which are chosen to isolate the V H → VWW associated production signals in the three-lepton signature. As such, we define three new regions for a WH analysis, a ZH 1-jet analysis, and a ZH ≥ 2-jet analysis with ... continued below

275 p.

### Creation Information

Nett, Jason Michael January 1, 2010.

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### Description

We present here the search for Standard Model V H → VWW → lll + E<sub>T</sub> (missing energy due to neutrinos) production, where V is a W or Z weak vector boson, which uses up to 5.9 fb<sup>-1</sup> of integrated luminosity. This analysis has recently added to the CDF high-mass Higgs group three new signal topologies characterized by a tri-lepton signature, which are chosen to isolate the V H → VWW associated production signals in the three-lepton signature. As such, we define three new regions for a WH analysis, a ZH 1-jet analysis, and a ZH ≥ 2-jet analysis with which we expect to contribute an additional 5.8% (for mH = 165 GeV) acceptance to the current H → WW dilepton analysis. The ZH trilepton regions are defined by events passing a Z-boson selection: events having at least one lepton pairing (among three possible pairings) with opposite sign, same flavor, and a dilepton invariant mass within [76.0, 106.0] GeV–a ± 15 GeV window around the Z-boson mass. TheWH trilepton region is then defined as the set of trilepton events that are complement to those chosen by the Z-boson selection. These three new event topologies make a substantial contribution to the H → WW group result. As a measure of the sensitivity of this search, we compute the median expected limit on the at 95% confidence level (“C.L.”) on the production cross section (effectively the rate of production) for a StandardModel Higgs boson and report the result as a ratio to the theoretical production cross section. An observed limit ratio of one or less at a given mass would rule out the production of a Standard Model Higgs boson at that mass with 95% confidence. At m<sub>H</sub> = 165 GeV, the WH analysis expected limits reach 7.2 times the standard model cross section; the ZH 1-jet analysis is set at 29 times the expected standard model cross section; the ZH ≥ 2-jet analysis is set at 9.9 times the expected standard model cross section; and the combined trilepton analysis is set at 4.9 times the expected standard model cross section. We announce that the combination of this trilepton V H → VWW Higgs boson search and the previous CDF dilepton H → WW search achieves an expected median limit of 1.00 at 165 GeV/c<sup>2</sup>. The expected median limit of 1.00 indicates we anticipate a 50% probability of ruling out the existence of a Standard Model Higgs boson with a mass of 165 GeV/c<sup>2</sup>. This is the first time a single hadron collider experiment has achieved sensitivity to the production of a Standard Model Higgs boson. We do not see evidence for a significant signal of Higgs bosons in the data and place observed limits on the production of a Standard Model Higgs boson of 165 GeV/c<sup>2</sup> at 1.08 times Standard Model production cross section. Matthew

275 p.

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• Report No.: FERMILAB-THESIS--2010-35
• Grant Number: AC02-07CH11359
• DOI: 10.2172/986981 | External Link
• Office of Scientific & Technical Information Report Number: 986981

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#### Office of Scientific & Technical Information Technical Reports

Reports, articles and other documents harvested from the Office of Scientific and Technical Information.

Office of Scientific and Technical Information (OSTI) is the Department of Energy (DOE) office that collects, preserves, and disseminates DOE-sponsored research and development (R&D) results that are the outcomes of R&D projects or other funded activities at DOE labs and facilities nationwide and grantees at universities and other institutions.

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### Creation Date

• January 1, 2010

### Added to The UNT Digital Library

• Oct. 14, 2017, 8:36 a.m.

### Description Last Updated

• Oct. 25, 2017, 4:16 p.m.

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Nett, Jason Michael. The Search for VH → VWW standard model higgs production in the trilepton signature with 5.9fb<sup>-1</sup> of data from p$\bar{p}$ collisions at √s=1.96 GeV, thesis or dissertation, January 1, 2010; Batavia, Illinois. (digital.library.unt.edu/ark:/67531/metadc1013015/: accessed November 17, 2017), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.