Modelling $b\bar b H$ production for the LHC at 13.6 TeV

TL;DR

The paper delivers a comprehensive, high-precision treatment of $b\bar bH$ production at $13.6$ TeV, comparing 5FS and 4FS, and advancing NNLO+PS predictions in both schemes. It introduces third-order transverse-momentum resummation, benchmarks MiNNLO$_{\textrm{PS}}$ against Geneva, and extends NNLO+PS for the 4FS, resolving long-standing scheme tensions. The work also analyzes $b\bar bH$ as a background to di-Higgs searches and investigates light-quark Yukawa contributions, including diphoton final states, to constrain $y_q$ couplings. Together, these results enhance the precision and reliability of bbH predictions for SM and BSM contexts, with direct relevance to Higgs coupling measurements and $HH$ analyses at the LHC.

Abstract

We present new state-of-the-art predictions for Standard Model Higgs boson production in association with a bottom-quark pair ($b\bar bH$). Updated cross sections are computed in accordance with the recommendations of the LHC Higgs Working Group, including the use of the PDF4LHC21 set of parton distribution functions, with a center-of-mass energy of 13.6 TeV. For the total inclusive cross section, we provide matched predictions of the massless five-flavour scheme (5FS) and the massive four-flavour scheme (4FS) at the fixed-order level. We further present recently obtained simulations matched with parton showers in both flavour schemes within the SM, and also discuss them in the context of potential BSM scenarios. In the massless scheme, we compare different NNLO+PS predictions obtained through the MiNNLOPS and GENEVA generators. In addition, the role of 4FS predictions is studied as a background to $HH$ searches, considering both the top-quark and bottom-quark Yukawa contributions to $b\bar bH$ production. Finally, we analyse the sensitivity of the Higgs transverse momentum spectrum to light-quark Yukawa couplings in the diphoton decay channel based on MiNNLOPS simulations.

Figures (14)

• Figure 1: Typical LO Feynman diagrams contributing to $b\bar{b}H$ production in the four-flavour scheme (left, centre) and the five-flavour scheme (right). Incoming particles are shown on the left, and final asymptotic states on the right. The Higgs boson is emitted from bottom quarks through the Yukawa coupling $y_b$.
• Figure 2: Typical one-loop Feynman diagrams for $b\bar{b}H$ production in the four-flavour scheme. The Higgs boson is produced through radiation off internal heavy-quark loops; for the dominant top-quark contribution, the corresponding vertex is governed by the Yukawa coupling $y_t$.
• Figure 3: Higgs transverse momentum spectrum in the 5FS predicted by the analytic resummed prediction at $\text{NNLO+NLO}$ (orange, dashed), $\text{N}^3\text{LL+NNLO}$ (blue, dotted) and $\text{N}^3\text{LL$^{\prime}$+aN}^3\text{LO}$ (green, solid) accuracy.
• Figure 4: Comparison of MiNNLO$_{\textrm{PS}}$ (blue, dashed) and Geneva (brown, dotted) predictions at NNLO+PS level in the 5FS for the transverse momentum distribution of the Higgs boson, where Geneva uses their default cumulant scale choice. The zoomed version on the right shows also the alternative spectrum scale choice of the Geneva generator (red, solid).
• Figure 5: Comparison of the Higgs transverse momentum spectrum predicted by analytic resummed predictions (green, solid) at $\text{N}^3\text{LL+NNLO}$ (left plot) and at $\text{N}^3\text{LL$^{\prime}$+aN}^3\text{LO}$ against the results obtained by the two Monte Carlo generators: MiNNLO$_{\textrm{PS}}$ (blue, dashed) and Geneva with cumulant (brown, dotted) and spectrum (red, solid) scale choices. All predictions are obtained in the 5FS for the $y_b^2$ contribution.