skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Search for the Standard Model Higgs Boson in ZH → μ+μ-b$$\bar{b}$$ Production at DØ and Evidence for the H→ b$$\bar{b}$$ Decay at the Tevatron

Thesis/Dissertation ·
DOI:https://doi.org/10.2172/1155870· OSTI ID:1155870
 [1]
  1. Univ. of Michigan, Ann Arbor, MI (United States)

search for ZH → μ+μ-b$$\bar{b}$$ is presented, using a Run 2 dataset with an integrated luminosity of 9.7 fb-1 collected by the DØ detector. Selected events contain at least two reconstructed jets and a Z candidate reconstructed with two opposite-sign charged muons. Random forests of decision trees are trained to distinguish between signal and background events in two orthogonal b-tag samples. The ZH → μ+μ-b$$\bar{b}$$b analysis is then combined with ZH → e+e-b$$\bar{b}$$ analysis. For the combined results of ZH → ℓ+ℓ-b$$\bar{b}$$b, no Higgs signal is observed, limits are set on the ZH cross-section BR(H→ b$$\bar{b}$$) for different Higgs masses, from 90 to 150 GeV. For a Standard Model (SM) Higgs boson of mass 125 GeV, the observed cross-section limit is 7.1 times the SM cross-section with an expected sensitivity of 5.1 times the SM cross section. The result of ZH → ℓ+ℓ-b$$\bar{b}$$b channel has been combined with searches in other Higgs decay channels at the Tevatron, which led to the first evidence of H → b$$\bar{b}$$.

Research Organization:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Organization:
USDOE Office of Science (SC), High Energy Physics (HEP)
DOE Contract Number:
AC02-07CH11359
OSTI ID:
1155870
Report Number(s):
FERMILAB-THESIS-2014-12
Country of Publication:
United States
Language:
English