Transverse-momentum resummation and the spectrum of the Higgs boson at the LHC

Abstract

We consider the transverse-momentum (q T ) distribution of generic high-mass systems (lepton pairs, vector bosons, Higgs particles, ....) produced in hadron collisions. At small q T , we concentrate on the all-order resummation of the logarithmicallyenhanced contributions in QCD perturbation theory. We elaborate on the b-space resummation formalism and introduce some novel features: the large logarithmic contributions are systematically exponentiated in a process-independent form and, after integration over q T , they are constrained by perturbative unitarity to give a vanishing contribution to the total cross section. At intermediate and large q T , resummation is consistently combined with fixed-order perturbative results, to obtain predictions with uniform theoretical accuracy over the entire range of transverse momenta. The formalism is applied to Standard Model Higgs boson production at LHC energies. We combine the most advanced perturbative information available at present for this process: resummation up to next-to-next-to-leading logarithmic accuracy and fixed-order perturbation theory up to next-to-leading order. The results show a high stability with respect to perturbative QCD uncertainties.

Higgs boson production at the LHC: Transverse-momentum resummation and rapidity dependence

“…To this purpose, we use the general (process-independent) strategy and the formalism described in detail in Ref. [44]. The only difference with respect to Ref.…”

“…The only difference with respect to Ref. [44] is that the resummation is now performed at fixed values of the rapidity y, rather than after integration over the rapidity phase space. In the following we briefly recall the main steps of the resummation formalism, and we point out explicitly the differences with respect to Ref.…”

“…In the following we briefly recall the main steps of the resummation formalism, and we point out explicitly the differences with respect to Ref. [44].…”

“…[44], we can straightforwardly obtain the functions H (N 1 ,N 2 ) and G (N 1 ,N 2 ) from the functions H N and G N . Roughly speaking, we simply have…”

Threshold resummation for high-transverse-momentum Higgs production at the LHC

“…Unless otherwise stated, we fix the the factorization and renormalization scales to µ 2 F = µ 2 R = p 2 T +m 2 H . The considered p T spectrum starts above p T = 80 GeV where the effects of small transverse momentum logarithms treated in [27,28,29,30] are less important.…”