Higgs pair production at next-to-next-to-leading logarithmic accuracy at the LHC (1505.07122v2)

Abstract: We perform the threshold resummation for Higgs pair production in the dominant gluon fusion channel to next-to-next-to-leading logarithmic (NNLL) accuracy. The calculation includes the matching to the next-to-next-to-leading order (NNLO) cross section obtained in the heavy top-quark limit, and results in an increase of the inclusive cross section up to 7% at the LHC with centre-of-mass energy Ecm=14TeV, for the choice of factorization and renormalization scales $\mu_F=\mu_R=Q$, being Q the invariant mass of the Higgs pair system. After the resummation is implemented, we estimate the theoretical uncertainty from the perturbative expansion to be reduced to about +-5.5%, plus ~10% from finite top-mass effects. The resummed cross section turns out to be rather independent of the value chosen for the central factorization and renormalization scales in the usual range (Q/2,Q).

Higgs Pair Production at NNLL Accuracy at the LHC

This paper presents a sophisticated calculation of Higgs pair production via gluon fusion at the Large Hadron Collider (LHC), achieved through threshold resummation up to next-to-next-to-leading logarithmic (NNLL) accuracy. The authors apply the resummation in conjunction with matching to the next-to-next-to-leading order (NNLO) cross-section, within the framework of the large top-quark mass approximation. They provide significant insight into the calculation of perturbative corrections, addressing the peculiarities of soft-gluon and virtual effects which dominate these higher-order corrections.

Key Numerical Results and Observations

The enhancement in the inclusive cross-section, upon employing NNLL resummation, reaches up to 7% at the LHC with a center-of-mass energy of $E_{cm} = 14 \, \text{TeV}$. Notably, the resummed cross-section exhibits a marked reduction in theoretical uncertainty due to perturbative expansion, which is quantified around ±5.5%. This reduction in uncertainty underscores the importance of NNLL resummation in providing more precise theoretical predictions compared to fixed-order calculations. Additionally, the paper reveals that the resummed cross-section is relatively insensitive to variations in the factorization and renormalization scales within the customary range, which is an important trait for enhancing prediction reliability.

Methodology and Exceptional Claims

The methodology hinges on leveraging soft-gluon emission resummation for improved precision. The computation incorporates a careful matching to NNLO results, ensuring consistency in predictions and better accounting of uncalculated higher-order terms through resummed logarithmic expansions. The paper claims that the NNLL results have reduced scale dependence and portray a more stable overlap in uncertainty bands, specifically between NNLL and NLL corrections, compared to NNLO vs. NLO bands. This development is particularly pertinent for Higgs boson pair production identification and measurement, enhancing the LHC's ability to distinguish between the Standard Model Higgs and potential new physics.

Implications and Future Directions

This research drives forward the understanding of Higgs pair production, chiefly elucidating the trilinear coupling's role via the dominant gluon fusion channel. By accomplishing more accurate Higgs pair production predictions, the paper aids in the reconstruction of the Higgs potential, pivotal for analyzing electroweak symmetry breaking. Such theoretical advancements are poised to complement experimental efforts in high-luminosity LHC runs, potentially unveiling new physics scenarios. Future directions should focus on integrating finite top-mass effects, as the uncertainty from these currently exceeds perturbative expansion uncertainties. Greater precision in the perturbative series could also be pursued through higher precision PDF sets or by encompassing N$^3$LL renormalization factors.

In sum, this paper signifies a substantial step toward improved theoretical precision in Higgs pair production processes at the LHC, thus bolstering the foundational understanding required for novel physics discoveries.