Dimuon production in neutrino-nucleus collisions at next-to-next-to-leading order in perturbative QCD

TL;DR

This paper presents a detailed NNLO perturbative QCD calculation of dimuon production in neutrino-nucleus DIS, addressing previous limitations and improving the understanding of strangeness content in PDFs.

Contribution

It introduces a self-contained NNLO calculation based on SIDIS, addressing previous inclusive approaches and exploring new heavy-quark channels.

Findings

NNLO corrections reduce scale uncertainties at large x

NNLO corrections are negative at small x, easing tension with LHC data

Improved theoretical precision enhances constraints on strange-quark PDFs

Abstract

Charm production in charged-current neutrino-nucleus deep-inelastic scattering (DIS), measured through dimuon final states, remains an important constraint of strangeness in global analyses of parton distribution functions (PDFs). This process has traditionally favored a smaller strange-quark PDF at small momentum fractions $x$ than what the LHC heavy-gauge boson data have indicated. Here, we present a self-contained next-to-next-to-leading-order (NNLO) perturbative QCD calculation of dimuon production in neutrino-nucleus DIS based on semi-inclusive DIS (SIDIS). This process has been previously computed at NNLO through fully inclusive charm production. We discuss the shortcomings of this approach and how they are addressed in the SIDIS picture. We study the perturbative convergence and explore new heavy-quark production channels that become available at NNLO. We find that the NNLO corrections significantly reduce the scale uncertainties at large values of $x$ where the cross sections are enhanced by the NNLO corrections. At small $x$, the NNLO corrections tend to be negative instead, which alleviate the tension between the dimuon and LHC data.