Jet veto resummation with jet rapidity cuts

Abstract

Jet vetoes are widely used in experimental analyses at the LHC to distinguish different hard-interaction processes. Experimental jet selections require a cut on the (pseudo)rapidity of reconstructed jets, |η jet | ≤ η cut . We extend the standard jet-p T (jet-veto) resummation, which implicitly works in the limit η cut → ∞, by incorporating a finite jet rapidity cut. We also consider the case of a step in the required p cut T at an intermediate value of |η| 2.5, which is of experimental relevance to avoid the increased pile-up contamination beyond the reach of the tracking detectors. We identify all relevant parametric regimes, discuss their factorization and resummation as well as the relations between them, and show that the phenomenologically relevant regimes are free of large nonglobal logarithms. The η cut dependence of all resummation ingredients is computed to the same order to which they are currently known for η cut → ∞. Our results pave the way for carrying out the jet-veto resummation including a sharp cut or a step at η cut to the same order as is currently available in the η cut → ∞ limit. The numerical impact of the jet rapidity cut is illustrated for benchmark qq and gg initiated color-singlet processes at NLL +NLO. We find that a rapidity cut at high η cut = 4.5 is safe to use and has little effect on the cross section. A sharp cut at η cut = 2.5 can in some cases lead to a substantial increase in the perturbative uncertainties, which can be mitigated by instead using a step in the veto.

Sleptons without hadrons

“…Extending jet vetoes to the forward region, 2.4 |η| 4.5, is avoided, among other reasons, to help to mitigate the contamination of pile-up activity, including the contribution to low-p T jets that would otherwise never exceed a veto threshold. This avoidance, however, is at the cost of an increased dependence on higher order QCD splittings, and hence an increased theoretical uncertainty [30]. On the other hand, it has recently been demonstrated that rapidity-dependent, jet vetoes, in particular one wherein p Veto T is relaxed for increasing jet pseudorapidity, can reduce this theoretical uncertainty [30], and are already experimentally viable [111].…”

“…This avoidance, however, is at the cost of an increased dependence on higher order QCD splittings, and hence an increased theoretical uncertainty [30]. On the other hand, it has recently been demonstrated that rapidity-dependent, jet vetoes, in particular one wherein p Veto T is relaxed for increasing jet pseudorapidity, can reduce this theoretical uncertainty [30], and are already experimentally viable [111]. Moreover, extending dynamic jet vetoes to the forward region was found to be necessary to ensure a sufficient suppression of SM backgrounds in studies at higher √ s [42].…”

“…Among the several promising lines of such investigations are those that consider the impact of jet vetoes (i.e., the rejection of events featuring jets with a transverse momentum greater than some threshold p Veto T [15- * Electronic address: fuks@lpthe.jussieu.fr † Electronic address: knordstrom@lpthe.jussieu.fr ‡ Electronic address: richard.ruiz@uclouvain.be § Electronic address: sophie.williamson@kit.edu 19]) in measurements of and searches for heavy, colorless SM [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] and beyond the SM [35][36][37][38][39][40][41][42] states. Interestingly, recent studies of multilepton searches for heavy, colorless exotic particles have demonstrated that dynamic jet vetoes can significantly improve discovery potential [41,42].…”

Doubly charged Higgs boson production at hadron colliders

“…An independent study by Ref. [101] shows that this is a reasonable approximation for jet veto windows that extend out to η max ∼ 4.5. For jet vetoes limited to η max 2.5, the computation grows more sensitive to higher order QCD radiation [101].…”

How much joint resummation do we need?

“…While many of these calculations have focussed on the resummation of a single logarithmic series, there has recently been a significant effort to jointly resum multiple logarithms. This includes the joint resummation of logarithms due to threshold production and transverse momentum [30][31][32][33][34][35][36], threshold and small x [37,38], transverse momentum and small x [39], transverse momentum and beam thrust [40,41], jet mass and dijet invariant mass [42,43], two angularities [44,45], jet veto and jet radius [46], jet mass and jet radius [47], jet vetoes and jet rapidity [48,49], and threshold and jet radius [50,51].…”