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  • Evert Curry posted an update 2 months ago

    Similar difficulties also appear when studying the evolution of double parton distribution functions in doubleparton scattering (DPS) processes [1268]; additional discussion on DPS is given in Sect. 5.2.4. As we go over in the next section, a lot in the existing work is, obviously, devoted to the study of your Higgs and its properties. Let us just highlight here 1 instance where superior handle more than QCD effects is vital, and for which current progress has been considerable. To optimize the sensitivity with the analyses, Higgs-search information are frequently separated into bins using a distinct CTX-0294885 number of jets inside the final state. In unique, for the Higgs coupling measurements and spin research, the H W + W – decay channel is fairly relevant; but within this channel there’s ?a sizable background coming from t t production, which after the tops decay can make a W + W – pair together with two b-quark jets. To reduce this background, events containing jets with transverse momentum above a specific threshold are rejected, i.e., one focuses on the 0-jet bin, which can be also called the jet-veto cross section. This restriction around the cross section enhances the higher-order QCD corrections for the procedure, by terms that contain logarithms on the transversemomentum veto scale (usually about 25?0 GeV) over the Higgs mass. A single should really be careful when estimating the perturbative uncertainty of fixed-order predictions for the jetveto cross section, because the cancellation of distinctive effects can cause artificially little estimations. A reliable process to estimate it was presented in [1269], and also the outcome is that the perturbative uncertainty for the jet-veto cross sec-tion is about 20 , that is comparable for the current statistical experimental uncertainty and larger than the systematic 1. It really is thus desirable to improve these theoretical predictions. There has been many progress, starting with [1270], which showed that the resummation may be performed at NLL accuracy, and its authors jir.2014.0026 also computed the NNLL terms related srep39151 using the jet radius dependence. Subsequently, resummation of those logarithms was performed at NNLL precision [1271?275]. An all-orders factorization formula was also place forward in Refs. [1272,1275] inside the SCET framework; its adequacy, though, has been questioned in Refs. [1271,1274]. In any case, the accuracy for this jet-veto cross section has significantly improved, and there is room to continue improving the understanding of jet-veto cross sections and their uncertainty. Connected to the discussion on the previous paragraph, one particular would also like to have resummed predictions for N -jet processes, by which we mean any procedure with N hard jets. Though there has been important current progress [1276, 1277] concerning the structure of infrared singularities in gauge theories, connecting them to N -jet operators and its evolution in SCET, several multi-jet processes involve socalled nonglobal logarithms [1278]. These are logarithms that arise in observables which can be sensitive to radiation in only a component of the phase space. Generally they seem at the NLL level, and even though several explicit computations of those kinds of terms have already been performed, it is actually not known ways to resum them in general. Their presence, hence, hinders the way to resummation for common N -jet cross sections. 1 might be forced to switch to simpler observables; see, e.