Search for the Higgs boson produced with $Z \to \ell^+\ell^-$ in $p\bar{p}$ collisions at $\sqrt{s}=$ 1.96 TeV

TL;DR

This paper reports a search for the Higgs boson produced with a Z boson decaying into leptons in proton-antiproton collisions at 1.96 TeV, using neural networks for event analysis, but finds no evidence and sets upper limits on production rates.

Contribution

It introduces the use of artificial neural networks for jet correction and background discrimination in Higgs searches at the Tevatron.

Findings

No evidence for Higgs production was observed.

Set 95% CL upper limits on cross section times branching ratio.

Limits range from 1.5 pb to 1.2 pb for Higgs masses 110-150 GeV/c^2.

Abstract

We present a search for the Higgs boson in the process $q\bar{q} \to ZH \to \ell^+\ell^- b\bar{b}$. The analysis uses an integrated luminosity of 1 fb$^{-1}$ of $p\bar{p}$ collisions produced at $\sqrt{s} =$ 1.96 TeV and accumulated by the upgraded Collider Detector at Fermilab (CDF II). We employ artificial neural networks both to correct jets mismeasured in the calorimeter, and to distinguish the signal kinematic distributions from those of the background. We see no evidence for Higgs boson production, and set 95% CL upper limits on $\sigma_{ZH} \cdot {\cal B}(H \to b\bar{b}$), ranging from 1.5 pb to 1.2 pb for a Higgs boson mass ($m_H$) of 110 to 150 GeV/$c^2$.