Dimuon production in DIS with charm-mass effects

TL;DR

The paper develops a SIDIS-based approach to dimuon production in neutrino-nucleus DIS within the SACOT-$\chi$ GM-VFNS, incorporating full charm-mass effects by computing semi-inclusive charmed-hadron production and applying an energy-dependent decay function for muons. It finds dynamical charm-mass corrections of up to $20\%$ at small $Q^2$, with results approaching the slow-rescaling baseline at large $Q^2$, and demonstrates consistency with modern nPDFs and data. This framework provides a systematically improvable alternative to the inclusive charm method, with planned NNLO extensions and relevance for global PDF analyses.

Abstract

Dimuon production in neutrino-nucleus collisions, an important constraint of strangeness in global parton distribution function analyses, is typically calculated by assuming it to be proportional to inclusive charm production. This approach breaks down beyond fixed-flavor leading-order calculations. In our previous work, we introduced an alternative approach based on semi-inclusive charmed-hadron production to compute dimuon production directly. We now present an extension to this work, where we compute the semi-inclusive hadron production in the SACOT-$χ$ general-mass variable-flavor number scheme to take all charm-mass effects consistently into account. The results are in line with our expectations, with the dynamical charm-mass effects modifying our previous approximative calculation by up to $20 \, \%$ at small values of $Q^2$.

Figures (1)

• Figure 1: Comparison of mass schemes with the EPPS21 nPDF at NLO with $\mu^2=Q^2+m_c^2$ in neutrino (top row) and antineutrino (bottom row) scattering. The uncertainty band depicts the envelope of all 17 scale combinations. The theoretical calculations and experimental NuTeV data are normalized to the central SR curve.