Factorization and resummation for single color-octet scalar production at the LHC

Abstract

Heavy colored scalar particles appear in a variety of new physics (NP) models and could be produced at the Large Hadron Collider (LHC). Knowing the total production cross section is important for searching for these states and establishing bounds on their masses and couplings. Using soft-collinear effective theory, we derive a factorization theorem for the process $pp\to SX$, where $S$ is a color-octet scalar, that is applicable to any NP model provided the dominant production mechanism is gluon-gluon fusion. The factorized result for the inclusive cross section is similar to that for the Standard Model Higgs production, however, differences arise due to color exchange between initial and final states. We provide formulae for the total cross section with large (partonic) threshold logarithms resummed to next-to-leading logarithm (NLL) accuracy. The resulting $K$-factors are similar to those found in Higgs production. We apply our formalism to the Manohar-Wise model and find that the NLL cross section is roughly 2 times (3 times) as large as the leading order cross section for a color-octet scalar of mass of 500 GeV (3 TeV). A similar enhancement should appear in any NP model with color-octet scalars.

Figures (5)

• Figure 1: One-loop renormalization of $O_{S,P}$. Here the curly lines with the straight lines are $n(\overline{n})$-collinear gluons and the only curly lines denote the soft gluons coming from the soft Wilson lines. Double line denotes outgoing color-octet field.
• Figure 2: One loop corrections to the soft function. The dashed line represents the cut. The diagram (a) and its Hermitian conjugate (b) describe the virtual soft gluon radiation and the diagram (c) denotes real soft gluon radiation.
• Figure 3: $K$-factor for the single color-octet production at LHC where $\sqrt{s} = 14$ TeV. The straight (dashed) line denotes NLL evaluation with (without) $\pi^2$-evolution.
• Figure 4: Scale dependences of the $K$-factor.
• Figure 5: The scattering cross sections employing Manohar-Wise Model at the LHC. In the both plots, the straight (dashed) lines denote the results at NLL (LO).