Scalar and Pseudoscalar Higgs Boson Plus One Jet Production at the LHC and Tevatron

TL;DR

The paper computes Higgs plus one-jet production for the SM and MSSM (h^0, H^0, A^0) at the LHC and Tevatron, including both top and bottom quark loops with full mass dependence and comparing to the Heavy Quark Effective Theory (HQET). It analyzes three partonic channels ($gg\to g\Phi$, $qg\to q\Phi$, $q\bar{q}\to g\Phi$) and provides a detailed treatment of HQET and small-mass limits to map the validity domain. Numerical results show that bottom-quark effects become crucial at large $\tan\beta$, especially for $A^0$, while interference between top and bottom loops significantly affects cross sections for $h^0$; HQET remains accurate mainly in regions where the bottom contribution is negligible. The study emphasizes the necessity of full-mass calculations for reliable predictions across MSSM parameter space and collider energies, guiding the interpretation of jet-associated Higgs signals. Overall, it delineates the parameter regions where HQET-based NLO results are applicable and where complete mass-dependent computations are required.

Abstract

The production of the Standard Model (SM) Higgs boson (H) in association with a jet is compared with that of the lightest scalar Higgs boson (h^0) and the pseudoscalar Higgs boson (A^0) of the Minimal Supersymmetric Model (MSSM) at both the CERN Large Hadron Collider (LHC) and the Fermilab Tevatron. We include both top and bottom quark loops to lowest order in QCD and investigate the limits of zero quark mass and infinite quark mass.

Figures (7)

• Figure 1: Sample Higgs plus one jet diagrams. Figures 1a,b are the $gg$ diagrams, 1c is the $qg$ channel, and 1d is the $q\bar{q}$ channel. All quarks contribute to the loops. The crossed and charge conjugate diagrams are not shown. There are a total of $12$$gg$ diagrams and $2$ for each of the $qg$ and $q\bar{q}$ sub-processes.
• Figure 2: The squared matrix elements, $|\mathcal{M}|^2$, evaluated at $\hat{s} = 4m_\Phi^2$ and $\hat{u}=\hat{t}$ for the three different channels, ($gg$, $qg$, $q\bar{q}$), normalized to the squared matrix elements in the HQET for scalar and pseudoscalar (with $g_A = 1$) Higgs plus jet production. We include only the top quark loops. The solid line is the scalar, whereas the dashed line is the pseudoscalar.
• Figure 3: Transverse momentum distributions for the SM Higgs boson plus one jet production at the LHC with $M_{H}=120$ GeV /c$^2$ for the different channels. The curves labeled 'Top' ('Bot') include ${\it only}$ the top (bottom) quark loops.
• Figure 4: Transverse momentum distributions for the SM Higgs ($H$) plus one jet and for a pseudoscalar ($A^0$) plus one jet in the full theory with only the top-quark loops included and in the HQET at the LHC for $M_{\Phi}=120$ GeV /c$^2$. We assume $g_A=1$.
• Figure 5: The transverse momentum distributions for the MSSM pseudoscalar Higgs boson for $\tan\beta=30,40,50$ and $M_{A^{0}} = 120$ GeV /c$^2$ at the Tevatron including the top and bottom quark loops. The top, middle, and bottom lines in the top graph are the curves for $\tan\beta = 50,40,30$ respectively. Below is the fraction of the process that comes from each of the different channels. The curves at $p_t = 250$ GeV /c from top to bottom are the $qg$, $gg$, and $q\bar{q}$ channels respectively.