Dimuons from neutrino-nucleus collisions in the semi-inclusive DIS approach

TL;DR

This paper introduces a direct semi-inclusive QCD calculation method for dimuon production in neutrino-nucleus collisions, improving accuracy and reducing uncertainties compared to traditional inclusive charm approaches.

Contribution

It develops a novel semi-inclusive approach for calculating dimuon production, avoiding external acceptance corrections and providing more precise uncertainty estimates.

Findings

Good agreement with experimental data

Reduced uncertainties from decay functions and scale dependence

Differences in effective acceptances of about 10% compared to global fits

Abstract

We present a next-to-leading order perturbative QCD calculation of dimuon production in neutrino-nucleus collisions. This process is typically calculated by assuming it to be proportional to inclusive charm production, which requires an effective acceptance correction to take the experimental cuts on the decay-muon kinematics into account. Here, we instead compute the dimuon production cross section directly as a convolution of semi-inclusive deep inelastic scattering to produce charmed hadrons, and a decay function fitted to $e^+e^-$ data to produce a muon from the charmed hadrons. The presented approach is in a good agreement with available experimental data and will serve as a starting point for higher-order QCD calculations without an external acceptance correction. The uncertainties arising from the decay function and scale dependence are sizeably smaller than those from the nuclear parton distribution functions. We also calculate the effective acceptances within our approach and compare them to those usually used in global fits of parton distribution functions, finding differences of the order of $10\,\%$, depending on the kinematics, perturbative order, and applied parton distributions.