Impact of isolation and (cid:12)ducial cuts on q T and N-jettiness subtractions

: Kinematic selection cuts and isolation requirements are a necessity in experimental measurements for identifying prompt leptons and photons that originate from the hard-interaction process of interest. We analyze how such cuts a(cid:11)ect the application of the q T and N -jettiness subtraction methods for (cid:12)xed-order calculations. We consider both (cid:12)xed-cone and smooth-cone isolation methods. We (cid:12)nd that kinematic selection and isolation cuts both induce parametrically enhanced power corrections with considerably slower convergence compared to the standard power corrections that are already present in inclusive cross sections without additional cuts. Using analytic arguments at next-to-leading order we derive their general scaling behavior as a function of the subtraction cuto(cid:11). We also study their numerical impact for the case of gluon-fusion Higgs production in the H ! (cid:13)(cid:13) decay mode and for pp ! (cid:13)(cid:13) direct diphoton production. We (cid:12)nd that the relative enhancement of the additional cut-induced power corrections tends to be more severe for q T , where it can reach an order of magnitude or more, depending on the choice of parameters and subtraction cuto(cid:11)s. We discuss how all such cuts can be incorporated without causing additional power corrections by implementing the subtractions di(cid:11)eren-tially rather than through a global slicing method. We also highlight the close relation of this formulation of the subtractions to the projection-to-Born method.