Iain W. Stewart, Frank J. Tackmann
Bounds on the Higgs mass from the Tevatron and LHC are determined using
exclusive jet bins to maximize sensitivity. Scale variation in exclusive
fixed-order predictions underestimates the perturbative uncertainty for these
cross sections, due to cancellations between the perturbative corrections
leading to large K factors and those that induce logarithmic sensitivity to the
jet-bin boundary. To account for this, we propose that scale variation in the
fixed-order calculations should be used to determine theory uncertainties for
inclusive jet cross sections, whose differences yield exclusive jet cross
sections. This yields a theory correlation matrix for the jet bins such that
the additional uncertainty from large logarithms due to the jet boundary
cancels when neighboring bins are added. This procedure is tested for H + 0, 1
jets, WW + 0 jets, and W + 0, 1, 2 jets, and found to be generally applicable.
For a case where the higher-order resummation of the jet boundary corrections
is known, we show that this procedure yields fixed-order uncertainties which
are theoretically consistent with those obtained in the resummed calculation.
View original:
http://arxiv.org/abs/1107.2117
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