W production at large transverse momentum at the Large Hadron Collider

TL;DR

The paper tackles precise predictions for $W$ production at large transverse momentum in $pp$ collisions at the LHC by computing the complete next-to-leading order (NLO) corrections and the next-to-next-to-leading-order (NNLO) soft-gluon corrections. It analyzes cross sections and scale dependence, finding that NLO corrections substantially increase the cross section but do not reduce scale uncertainty relative to LO, while NNLO soft-gluon corrections are small in magnitude yet significantly reduce scale dependence, enhancing theoretical stability. The work uses the MRST2002 parton densities and assesses how PDF choices and scale variations affect the results, providing more reliable predictions for SM tests, PDF extractions, and new-physics searches. Overall, the study delivers high-precision QCD predictions for inclusive $W$ production at large $Q_T$ crucial for LHC phenomenology.

Abstract

We study the production of W bosons at large transverse momentum in pp collisions at the Large Hadron Collider (LHC). We calculate the complete next-to-leading order (NLO) corrections to the differential cross section. We find that the NLO corrections provide a large increase to the cross section but, surprisingly, do not reduce the scale dependence relative to leading order (LO). We also calculate next-to-next-to-leading-order (NNLO) soft-gluon corrections and find that, although they are small, they significantly reduce the scale dependence thus providing a more stable theoretical prediction.

Figures (7)

• Figure 1: The differential cross section, $d\sigma/dQ_T^2$, for $W$ production in $pp$ collisions at the LHC with $\sqrt{S}=14$ TeV and $\mu=\mu_F=\mu_R=Q_T$. Shown are the LO, NLO, and NNLO-NNNLL results.
• Figure 2: The $K$-factors for the differential cross section, $d\sigma/dQ_T^2$, for $W$ production in $pp$ collisions at the LHC with $\sqrt{S}=14$ TeV and $\mu=\mu_F=\mu_R=Q_T$. Shown are the $K$- factors for NLO/LO and NNLO-NNNLL/NLO. The latter is shown with the same or different parton distribution functions (pdf) for the NLO and NNLO results.
• Figure 3: The differential cross section, $d\sigma/dQ_T^2$, for $W$ production in $pp$ collisions at the LHC with $\sqrt{S}=14$ TeV, $Q_T=50$ GeV, and $\mu=\mu_F=\mu_R$. Shown are the LO, NLO, and NNLO-NNNLL results.
• Figure 4: The differential cross section, $d\sigma/dQ_T^2$, for $W$ production in $pp$ collisions at the LHC with $\sqrt{S}=14$ TeV, $Q_T=80$ GeV, and $\mu=\mu_F=\mu_R$. Shown are the LO, NLO, and NNLO-NNNLL results.
• Figure 5: The differential cross section, $d\sigma/dQ_T^2$, for $W$ production in $pp$ collisions at the LHC with $\sqrt{S}=14$ TeV, $Q_T=150$ GeV, and $\mu=\mu_F=\mu_R$. Shown are the LO, NLO, and NNLO-NNNLL results.