Search for the standard model Higgs boson in $\bm{\ell\nu}$+jets final states in 9.7~fb$\bm{^{-1}}$ of $\bm{p\bar{p}}$ collisions with the D0 detector

TL;DR

This paper reports a detailed search for the standard model Higgs boson in specific final states using data from the D0 detector, setting upper limits on production at 125 GeV and testing various models.

Contribution

It introduces a comprehensive analysis method for Higgs searches in $m{ ext{l} u}$+jets final states, including categorization and background estimation, with new limits set at 125 GeV.

Findings

Observed data agrees with background expectations.

Set 95% CL upper limit on Higgs production at 125 GeV.

Measured WZ and ZZ production rates consistent with the standard model.

Abstract

We present, in detail, a search for the standard model Higgs boson, $H$, in final states with a charged lepton (electron or muon), missing energy, and two or more jets in data corresponding to 9.7 fb$^{-1}$ of integrated luminosity collected at a center of mass energy of $\sqrt{s}$ = 1.96 TeV with the D0 detector at the Fermilab Tevatron $p\bar{p}$ Collider. The search uses $b$-jet identification to categorize events for improved signal versus background separation and is sensitive to associated production of the $H$ with a $W$ boson, $WH\to\ell\nu b\bar{b}$; gluon fusion with the Higgs decaying to $W$ boson pairs, $H\to WW\to\ell\nu jj$; and associated production with a vector boson where the Higgs decays to $W$ boson pairs, $VH\to VWW \to \ell\nu jjjj$ production (where $V = W$ or $Z$). We observe good agreement between data and expected background. We test our method by measuring $WZ$ and $ZZ$ production with $Z\to b\bar{b}$ and find production rates consistent with the standard model prediction. For a Higgs boson mass of 125 GeV, we set a 95%\ C.L. upper limit on the production of a standard model Higgs boson of \obslimA$\times\sigma_{\rm SM}$, where $\sigma_{\rm SM}$ is the standard model Higgs boson production cross section, while the expected limit is \explimA$\times\sigma_{\rm SM}$. We also interpret the data considering models with fourth generation fermions, or a fermiophobic Higgs boson.