Higgs-Boson Production in Association with a Single Bottom Quark

TL;DR

The paper addresses Higgs production in association with a single high-pT bottom quark in models with enhanced bottom Yukawa couplings. It develops a complete NLO QCD calculation of the gb->hb process, including 1/ln(mh/mb) and O(αS) corrections, and compares to the gg/q qbar -> bb h channel. The results show gb->hb yields cross sections an order of magnitude larger than bbh production in the relevant kinematic regime, with reduced scale uncertainties at NLO, thereby improving discovery prospects for b-enhanced Higgs bosons. The authors provide numerical predictions for Tevatron and LHC and implement the calculation in MCFM for use in future studies and experimental analyses with b-tagging.

Abstract

Higgs bosons from an extended Higgs sector, such as a two-Higgs-doublet model, can have greatly enhanced coupling to the bottom quark. Producing such a Higgs boson in association with a single high-p_T bottom quark via g b -> h b allows for the suppression of backgrounds. Previous studies have instead used g g,qbar q -> bbar b h as the production mechanism, which is valid only if both b quarks are at high p_T. We calculate g b -> h b at next-to-leading order in QCD, and find that it is an order of magnitude larger than g g,qbar q -> bbar b h at the Fermilab Tevatron and the CERN Large Hadron Collider. This production mechanism improves the prospects for the discovery of a Higgs boson with enhanced coupling to the b quark.

Figures (12)

• Figure 1: Production of the Higgs boson via $b\bar{b}\to h$. There are typically no high-$p_T$ bottom quarks in the final state.
• Figure 2: Associated production of the Higgs boson and a single high-$p_T$ bottom quark.
• Figure 3: Representative diagrams for associated production of the Higgs boson and two high-$p_T$ bottom quarks: (a) $gg\to b\bar{b}h$ (8 diagrams); (b) $q\bar{q}\to b\bar{b}h$ (2 diagrams).
• Figure 4: Virtual correction to $gb\to hb$. External-leg wavefunction renormalization diagrams (not shown) vanish in modern dimensional reduction for massless particles.
• Figure 5: Representative diagrams for subprocesses contributing to the real correction to $gb\to hb$: (a) $gb\to gbh$ (8 diagrams); (b) $q(\bar{q})b\to q(\bar{q})bh$ (2 diagrams); (c) $bb\to bbh$ (8 diagrams); $b\bar{b}\to b\bar{b}h$ (8 diagrams).