Joint resummation for Higgs boson production

Abstract

We study the application of the joint resummation formalism to Higgs boson production via gluon-gluon fusion at the CERN LHC, defining inverse transforms by analytic continuation. We work at next-to-leading logarithmic accuracy. We find that at low Q T the resummed Higgs Q T distributions are comparable in the joint and pure-Q T formalisms, with a relatively small influence from threshold enhancement in this range. We find a modest ͑about ten percent͒ decrease in the inclusive cross section, relative to pure threshold resummation.

Evolution of the helicity and transversity. Transverse-momentum-dependent parton distributions

“…(29,30) and Eqs. (36,37) represent the original results of this paper. They allow us to write epxressions for the helicity and transversity TMDs that fulfill TMD evolution equations, Eqs.…”

“…[36,37]). Any change in the prescription should also be combined with a change of the nonperturbative function f NP .…”

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

“…We also emphasize that the logarithms we are resumming are different from those occurring at small p T (p T ≪ m H ), which have received much attention in the literature [27,28,29,30] since the bulk of the inclusive events is in this regime. Here, the resummation has been carried out through NNLL [29], and also a formalism was applied [30] that allows a NLL resummation of the logarithms at low p T jointly with the threshold logarithms present in the inclusive (p T -integrated) Higgs cross section. Finally, we mention that for a very light Higgs and/or at high p T , p T ≫ m H , yet another class of logarithms could become important, arising through "fragmentation" production of the Higgs by a finalstate gluon.…”

“…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.…”

QCD corrections to Higgs physics at the LHC

“…These predictions in fixed-order perturbation theory have been supplemented with the resummation of higher-order corrections due to multiple soft-gluon emission. In the region of small transverse-momentum, q T -resummation has been performed at the NNLL level [23], while joint (threshold and q T ) resummation has been performed at the full NLL level [24].…”