Dimension-six triple gluon operator in $\mathrm{Higgs}+\mathrm{jet}$ observables

Recently a lot of progress has been made towards a full classification of new physics effects in Higgs observables by means of effective dimension-six operators. Specifically, Higgs production in association with a high transverse momentum jet has been suggested as a way to discriminate between operators that modify the Higgs-top coupling ($O_t$) and operators that induce an effective Higgs-gluon coupling ($O_g$)—a distinction that is hard to achieve with signal strength measurements alone. With this article we would like to draw attention to another source of new physics in $\mathrm{Higgs}+\mathrm{jet}$ observables: the triple gluon operator $O_{3g}$ (consisting of three factors of the gluon field strength tensor). We compute the distortions of kinematic distributions in $\mathrm{Higgs}+\mathrm{jet}$ production at a 14 TeV LHC due to $O_{3g}$ and compare them with the distortions due to $O_t$ and $O_g$. We find that the transverse momentum distributions alone cannot discriminate between $O_{3g}$ and $O_g$ if the coefficient of the operator $O_t$ treated as an unknown parameter. We further show that the jet rapidity and the difference between the Higgs and jet rapidity are well suited to remove this new degeneracy. Using rough estimates for the expected bounds we find that allowed distortions in kinematic distributions due to $O_g$ are of similar size as those due to $O_{3g}$. We conclude that a full analysis of new physics in $\mathrm{Higgs}+\mathrm{jet}$ observables must take the contributions from $O_{3g}$ into account.

Figure 1

Representative diagrams for $gg\to Hg$ in the SM.

Figure 2

Representative diagrams for $gg\to Hg$ mediated by $O_g$.

Figure 3

Kinematic distributions due to the differential cross sections defined in (7) for $\mathrm{\Lambda }=1\mathrm{TeV}$ and a 14 TeV LHC. A lower $p_T$ cut of 200 GeV was applied in all plots. Note the sign flips introduced to plot on a logarithmic scale and the scaling of $d{\sigma }_g$ and $d{\sigma }_{3g}$! The left column shows event counts for an integrated luminosity of $300{\mathrm{fb}}^{-1}$. The right column shows event ratios normalized to the contribution from $d{\sigma }_{\mathrm{SM}}$. See text for further details.