N-jettiness subtractions for gg → H at subleading power

Abstract

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, T[subscript N], subleading power corrections in τ=T[subscript N]/Q, with Q a hard interaction scale, can also be systematically computed. We study the structure of power corrections for 0-jettiness, T[subscript 0], for the gg→H process. Using the soft-collinear effective theory we analytically compute the leading power corrections α[subscript s]τlnτ and α[subscript s][superscript 2]τln][superscript 3]τ (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 q[¯ over q] channels. This includes a numerical extraction of the α[subscript s]τ and α[subscript s][superscript 2]τln[superscript 2]τ corrections, and a study of the dependence on the T[subscript 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 q[¯ over 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.