Adding Stroboscopic Muon Information For Reduction of Systematic Uncertainties in DUNE

TL;DR

This paper proposes using precise low-intensity muon momentum measurements, obtained via time-of-flight techniques, to reduce systematic uncertainties in neutrino flux predictions for DUNE, by leveraging stroboscopic analysis of muons and neutrinos.

Contribution

It introduces a novel approach of employing stroboscopic muon measurements and timing techniques to improve flux accuracy in neutrino experiments, especially before the Absorber Hall becomes too hot.

Findings

Muons can be measured precisely using psec timing and time-of-flight methods.

Low-momentum muon spectra can be cross-normalized with high-intensity neutrino data.

The approach can significantly reduce systematic uncertainties in neutrino flux measurements.

Abstract

Muons have a similar latency/energy correlation from pion decay as do the neutrinos, and hence in each time-slice in a stroboscopic analysis measurements of their momentum spectra can reduce systematic uncertainties due to flux. There are, however, unique issues for muons: 1) during standard neutrino data-taking muon measurements in the forward direction must be in formidable high-flux high-radiation environments; 2) because of the very high incident hadron flux in the Absorber Hall, muons must be detected after a thick absorber, imposing a range cutoff at a momentum much above the minimum neutrino momentum of interest; 3) the muon velocity, unlike that of neutrinos, differs from $c$, and so the muon detected time will require correction for the muon flight path, requiring measurement of the muon momentum; 4) multiple scattering is significant for low-momentum muons, and so a `good geometry' is essential for precision muon flux measurements; and 5) developments in psec timing allow muon momenta in the momentum region of interest to be measured precisely by time-of-flight over short distances with photodetectors of a few-psec resolution. Here we advocate that a program of extensive precise low-intensity muon momentum spectrum measurements be carried out early in the LBNF program before the Absorber Hall becomes too hot. The low-momentum muon spectra taken in this experiment would be cross-normalized to the high-intensity neutrino data through the currently planned muon monitors which can operate in both the low and high intensity geometries. While beyond the scope of uniquely muon-related issues, the note includes a proposal for an long-base-line oscillation analysis strategy that exploits stroboscopic information for both neutrinos and muons to reduce systematic uncertainties on the neutrino fluxes and event selection in Far and Near detectors.