Methods to Determine Neutrino Flux at Low Energies:Investigation of the Low $\nu$ Method

TL;DR

This paper explores extending the low-$ u$ method for neutrino flux determination to very low energies, below 1 GeV, by adjusting $ u_{cut}$ values, enabling accurate flux measurements in the quasielastic and resonance regions.

Contribution

It demonstrates that the low-$ u$ method can be adapted for low-energy neutrino flux measurements using smaller $ u_{cut}$ thresholds in active detectors.

Findings

The method is feasible down to 0.7 GeV neutrino energies.

Using $ u_{cut}$ of 0.25 and 0.50 GeV extends the method to low energies.

Application in detectors like MINERvA is possible at these low energies.

Abstract

We investigate the "low-$\nu$" method (developed by the CCFR/NUTEV collaborations) to determine the neutrino flux in a wide band neutrino beam at very low energies, a region of interest to neutrino oscillations experiments. Events with low hadronic final state energy $\nu<\nu_{cut}$ (of 1, 2 and 5 GeV) were used by the MINOS collaboration to determine the neutrino flux in their measurements of neutrino ($\nu_\mu$) and antineutrino ($\nub_\mu$) total cross sections. The lowest $\nu_\mu$ energy for which the method was used in MINOS is 3.5 GeV, and the lowest $\nub_\mu$ energy is 6 GeV. At these energies, the cross sections are dominated by inelastic processes. We investigate the application of the method to determine the neutrino flux for $\nu_\mu$, $\nub_\mu$ energies as low as 0.7 GeV where the cross sections are dominated by quasielastic scattering and $\Delta$(1232) resonance production. We find that the method can be extended to low energies by using $\nu_{cut}$ values of 0.25 and 0.50 GeV, which is feasible in fully active neutrino detectors such as MINERvA.