We use the theory of YFS resummation to compute the size of the expected resummed soft radiative threshold effects in precision studies of heavy particle production at the LHC, where accuracies of 1% are desired in some processes. We find that the soft QED threshold effects are at the level of 0.3% whereas the soft QCD threshold effects enter at the level of 20% and hence both must be controlled to be on the conservative side to achieve such goals.

We present a fully analytic calculation of the Higgs boson transverse momentum and rapidity distributions, for nonzero Higgs p ⊥ , at next-to-leading order in the infinite-top-mass approximation. We separate the cross section into a part that contains the dominant soft, virtual, collinear, and small-p ⊥ -enhanced contributions, and the remainder, which is organized by the contributions due to different parton helicities. We use this cross section to investigate analytically the small-p ⊥ limit and compare with the expectation from the resummation of large logarithms of the type ln m H /p ⊥ . We also compute numerically the cross section at moderate p ⊥ where a fixed-order calculation is reliable. We find a K-factor that varies from ≈ 1.6 − 1.8, and a reduction in the scale dependence, as compared to leading order. Our analysis suggests that the contribution of current parton distributions to the total uncertainty on this cross section at the LHC is probably less than that due to uncalculated higher orders.

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