Non-perturbative effects and the resummed Higgs transverse momentum distribution at the LHC

TL;DR

This paper addresses how non-perturbative physics affects the resummed Higgs transverse-momentum distribution at the LHC by comparing $b$-space (CSS) and $p_T$-space resummation formalisms.Non-perturbative inputs are parameterized by Gaussian-like functions in $b$-space and by a Gaussian-like function $\tilde{F}^{NP}$ in $p_T$-space, with logarithmic dependences on $Q$ and $\sqrt{s}$; the study uses low-energy hadroproduction data, including Drell-Yan and $\Upsilon$, to constrain these inputs.The authors test several parameterizations (DSW, LY, BLNY) and examine the possible scaling of gluon-initiated contributions by $C_A/C_F$, finding substantial model dependence and sizable uncertainties in the Higgs $p_T$ predictions.They conclude that non-perturbative effects induce an uncertainty band on the Higgs $p_T$ distribution at the LHC that is larger in the $p_T$-space approach than in the $b$-space approach, highlighting the need for improved constraints from gluon-initiated data.

Abstract

We investigate the form of the non-perturbative parameterization in both the impact parameter (b) space and transverse momentum (p_T) space resummation formalisms for the transverse momentum distribution of single massive bosons produced at hadron colliders. We propose to analyse data on Upsilon hadroproduction as a means of studying the non-perturbative contribution in processes with two gluons in the initial state. We also discuss the theoretical errors on the resummed Higgs transverse momentum distribution at the LHC arising from the non-perturbative contribution.

Figures (10)

• Figure 1: Two-parameter fit to E605, R209 and CDF $Z$ data (Run 0) data samples chosen as in BLLY
• Figure 2: Two-parameter fit to E288, E605, R209, CDF and D0 $Z$ (Run I) data samples chosen as described in text.
• Figure 3: Three-parameter fit to E288, E605, R209, CDF and D0 $Z$ (Run I) data samples chosen as described in text. The parallel lines correspond to non-perturbative function of the form (\ref{['rwBLNY']}) with coefficients (\ref{['rwBLNY:param']}) and values of $\sqrt s$ of each experiment analysed. The line marked 'BLNY' corresponds to the BLLY fit of the form (\ref{['BLNY']}) with coefficients (\ref{['BLNYparam']}) at $\sqrt s=38.8$ GeV.
• Figure 4: E605 Drell-Yan (7 GeV$<Q<$8 GeV, 8 GeV$<Q<$9 GeV, 10.5 GeV$<Q<$11.5 GeV bins) and $\Upsilon$ data compared to theoretical predictions using the best three-parameter fit. In order to better compare the shapes of the $p_T$ distribution, the Drell Yan data have been rescaled by the factor of 0.3, 0.6, 2.1 for the 7 GeV$<Q<$8 GeV, 8 GeV$<Q<$9 GeV and 10.5 GeV$<Q<$11.5 GeV bins in $Q$, respectively.
• Figure 5: Drell-Yan (E288, E605, R209), Z production (CDF and D0 Run 1) and E605 Upsilon data together with the three-parameter fits, (\ref{['BLNY']}) and (\ref{['rwBLNY']}) at $\sqrt s=38.8$ GeV, with coefficients (\ref{['BLNYparam']}) and (\ref{['rwBLNY:param']}) modified as discussed in text.