Energy-energy correlation in the back-to-back region at N3LL+NNLO in QCD [Energy-energy correlation in the back-to-back region at N³LL+NNLO in QCD]

We consider the energy-energy correlation (EEC) function in high-energy electron-positron annihilation to hadrons. In the back-to-back (two-jet) region, we perform the all-order resummation of the logarithmically enhanced contributions in QCD perturbation theory up to next-to-next-to-next-to-leading logarithmic (N3LL) accuracy. Away from the back-to-back region, we consistently combine resummed predictions with the known fixed-order results up to next-to-next-to-leading order (NNLO), and we are able to obtain an accurate fit of the O(αS3) remainder function from the numerical QCD computation of the full spectrum. All perturbative terms up to order αS3 are included in our calculation, and a nontrivial cross-check in the back-to-back region is obtained by comparing the soft collinear effective theory analytic calculation against the corresponding numerical QCD computation. In particular, the values of the O(αS3) resummation coefficients have been numerically verified. We regularize the Landau singularity of the QCD coupling within the so-called minimal prescription, and we discuss the reduction of the perturbative scale dependence of distributions at higher orders, as a means to estimate the corresponding residual perturbative uncertainty. Finally, after introducing within a dispersive approach nonperturbative power corrections, we are able to obtain an accurate description of experimental data at the LEP and SLC accelerators.