Production of a W boson and two jets with one b-quark tag

TL;DR

Addresses the background problem posed by W boson production with jets containing heavy flavor for searches at the Tevatron and LHC. It delivers a full NLO QCD calculation for W+jet production with one or more b quarks using MCFM, including treatment of bottom-quark mass effects and initial-state b-quark distributions. The results reveal substantial NLO corrections and important distinctions between Tevatron and LHC event compositions, with Wbj generally dominating at the LHC and Wbb remaining a non-negligible background. The study provides cross sections, differential distributions, and uncertainty estimates to inform background modeling for single-top, Higgs, and new-physics searches.

Abstract

The production of a W boson and two jets, at least one of which contains a b quark, is a principal background to single-top production, Higgs production, and signals of new physics at hadron colliders. We present a next-to-leading-order (NLO) calculation of the cross section at the Fermilab Tevatron and the CERN Large Hadron Collider. The NLO cross section differs substantially from that at LO, and we provide a context in which to understand this result.

Figures (10)

• Figure 1: Leading-order processes for the production of a $W$ boson and two jets, at least one of which contains a $b$ quark.
• Figure 2: An alternative way of calculating the process in Fig. \ref{['fig:Wbb']}(b).
• Figure 3: Renormalization- and factorization-scale dependence of the inclusive $Wbj+X$ cross section at LO (dashed) and NLO (solid) at the Tevatron. The cross section is normalized to its value at the reference scale $\mu_0=M_W$.
• Figure 4: Same as Fig. \ref{['fig:mudep_wbj_tev']}, but at the LHC.
• Figure 5: Exclusive NLO differential cross sections at the Tevatron ($\sqrt{s}=1.96$ TeV $p\bar{p}$, $p_T>15$ GeV, $|\eta|<2$, $\Delta R_{jj}>0.7$) for $Wbb$ (blue or black) and $Wbj$ (red or gray), versus the transverse momentum ($p_T$) of the highest-$p_T$ jet. Also shown is the distribution for the NLO process $W(b\bar{b})j$ (magenta or light gray, dot-dashed), in which a jet contains two $b$ quarks. The lower histogram shows the ratio of the NLO and LO cross sections.