$N$-jettiness subtractions provide a general approach for performing fully-differential next-to-next-to-leading order (NNLO) calculations. Since they are based on the physical resolution variable $N$-jettiness, $mathcal{T}_N$, subleading power corrections in $tau=mathcal{T}_N/Q$, with $Q$ a hard interaction scale, can also be systematically computed. We study the structure of power corrections for $0$-jettiness, $mathcal{T}_0$, for the $ggto H$ process. Using the soft-collinear effective theory we analytically compute the leading power corrections $alpha_s tau lntau$ and $alpha_s^2 tau ln^3tau$ (finding partial agreement with a previous result in the literature), and perform a detailed numerical study of the power corrections in the $gg$, $gq$, and $qbar q$ channels. This includes a numerical extraction of the $alpha_stau$ and $alpha_s^2 tau ln^2tau$ corrections, and a study of the dependence on the $mathcal{T}_0$ definition. Including such power suppressed logarithms significantly reduces the size of missing power corrections, and hence improves the numerical efficiency of the subtraction method. Having a more detailed understanding of the power corrections for both $qbar q$ and $gg$ initiated processes also provides insight into their universality, and hence their behavior in more complicated processes where they have not yet been analytically calculated.
تحميل البحث