Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

Observing H -> W*W* -> e mu pT(miss) in weak boson fusion with dual forward jet tagging at the LHC

D. Rainwater, D. Zeppenfeld

TL;DR

The paper investigates observing an intermediate-mass Higgs via H -> W(*)W(*) in weak-boson fusion with dual forward jet tagging at the LHC, focusing on the e mu plus missing pT final state. Using a parton-level Monte Carlo framework, it shows that forward tagging, central jet vetoes, b-jet vetoes, and kinematic/angular cuts can suppress dominant backgrounds enough to yield a robust signal at modest luminosities, with S/B ranging around 1/2 to 2 depending on mH. It also analyzes minijet radiation patterns with TSA and exponentiation models to quantify the effectiveness of a central minijet veto, enabling further background suppression with modest signal loss, and demonstrates a feasible mass reconstruction strategy via a transverse mass observable MT_WW. The work highlights experimental calibration via Zjj processes and argues that this WBF channel offers a competitive and complementary path to Higgs discovery in the 130–200 GeV window, alongside gluon-fusion channels.

Abstract

Weak boson fusion promises to be a copious source of intermediate mass Standard Model Higgs bosons at the LHC. The additional very energetic forward jets in these events provide for powerful background suppression tools. We analyze the H -> W^(*)W^(*) -> e mu pTmiss decay mode for a Higgs boson mass in the 130-200 GeV range. A parton level analysis of the dominant backgrounds (production of W pairs, tt~ and Z -> tau tau in association with jets) demonstrates that this channel allows the observation of H -> W^(*)W^(*) in a virtually background-free environment, yielding a significant Higgs boson signal with an integrated luminosity of 5 fb^-1 or less. Weak boson fusion achieves a much better signal to background ratio than inclusive H -> e mu pTmiss and is therefore the most promising search channel in the 130-200 GeV mass range.

Observing H -> W*W* -> e mu pT(miss) in weak boson fusion with dual forward jet tagging at the LHC

TL;DR

The paper investigates observing an intermediate-mass Higgs via H -> W(*)W(*) in weak-boson fusion with dual forward jet tagging at the LHC, focusing on the e mu plus missing pT final state. Using a parton-level Monte Carlo framework, it shows that forward tagging, central jet vetoes, b-jet vetoes, and kinematic/angular cuts can suppress dominant backgrounds enough to yield a robust signal at modest luminosities, with S/B ranging around 1/2 to 2 depending on mH. It also analyzes minijet radiation patterns with TSA and exponentiation models to quantify the effectiveness of a central minijet veto, enabling further background suppression with modest signal loss, and demonstrates a feasible mass reconstruction strategy via a transverse mass observable MT_WW. The work highlights experimental calibration via Zjj processes and argues that this WBF channel offers a competitive and complementary path to Higgs discovery in the 130–200 GeV window, alongside gluon-fusion channels.

Abstract

Weak boson fusion promises to be a copious source of intermediate mass Standard Model Higgs bosons at the LHC. The additional very energetic forward jets in these events provide for powerful background suppression tools. We analyze the H -> W^(*)W^(*) -> e mu pTmiss decay mode for a Higgs boson mass in the 130-200 GeV range. A parton level analysis of the dominant backgrounds (production of W pairs, tt~ and Z -> tau tau in association with jets) demonstrates that this channel allows the observation of H -> W^(*)W^(*) in a virtually background-free environment, yielding a significant Higgs boson signal with an integrated luminosity of 5 fb^-1 or less. Weak boson fusion achieves a much better signal to background ratio than inclusive H -> e mu pTmiss and is therefore the most promising search channel in the 130-200 GeV mass range.

Paper Structure

This paper contains 11 sections, 22 equations, 4 figures, 3 tables.

Table of Contents

  1. Introduction
  2. Calculational Tools
  3. The $qq\to qqH(g)$ signal process
  4. The QCD $t \bar{t} + jets$ backgrounds
  5. The QCD $WW+jj$ background
  6. The EW $WW+jj$ background
  7. The QCD and EW $\tau^+\tau^-$ backgrounds
  8. Detector resolution
  9. Higgs signal and real $W^+W^-$ backgrounds
  10. Radiation patterns of minijets
  11. Discussion

Figures (4)

  • Figure 1: Normalized invariant mass distribution of the two tagging jets for the signal (red) and various backgrounds: $t\bar{t} + jets$ (blue), QCD $WWjj$ (solid green), EW $WWjj$ (solid purple), QCD $\tau\tau +jj$ (dashed green) and EW $\tau\tau +jj$ (dashed purple). The cuts of Eqs. (\ref{['eq:basic']}-\ref{['eq:bveto']}) are imposed.
  • Figure 2: Normalized angular distributions of the charged leptons: azimuthal opening angle, lab opening angle, and separation in the lego plot. Results are shown for a Higgs boson mass of 160 GeV and 190 GeV (solid and dashed red lines) and for the various backgrounds as in Fig. \ref{['fig:Mjj']}. Lepton angular separation is clearly smaller for the $m_H = 160$ GeV scenario. The cuts of Eqs. (\ref{['eq:basic']}-\ref{['eq:bveto']}) are imposed.
  • Figure 3: Normalized distributions of the dilepton invariant mass and maximum charged lepton momentum after the cuts of Eqs. (\ref{['eq:basic']}-\ref{['eq:bveto']}). Results are shown for a Higgs boson mass of 160 GeV and 190 GeV (solid and dashed red lines) and for the various backgrounds as in Fig. \ref{['fig:Mjj']}. The $m_H = 160$ GeV curve peaks at lower values of $m_{e\mu}$ and $p_{T_{\ell,max}}$.
  • Figure 4: Dilepton-$/\!\!\!p_T$ transverse mass distributions expected for a Higgs boson of mass $m_H$ = 130, 160, and 190 GeV (red) after the cuts of Eqs. (\ref{['eq:basic']}-\ref{['eq:adv']}) and application of all detector efficiencies and a minijet veto with $p_{T,{\rm veto}} = 20$ GeV. Also shown is the background only (dashed).