Physics Prospects with MeV Neutrino-Argon Charged Current Interactions using Enhanced Photon Detection in Future LArTPCs

Abstract

We investigate MeV-scale electron neutrino charged current interactions in a liquid argon time projection chamber equipped with an enhanced photon detection system. Using simulations of deposited energy in charge and light calorimetry, we explore the potential for dual calorimetric neutrino energy reconstruction. We found energy reconstruction based on light-only calorimetry has a better resolution than combined charge and light calorimetry when hadrons are produced in these events. Meanwhile, enhanced light detection offers improved nanosecond timing resolution and broad optical coverage, enabling neutron tagging and identification of delayed low-energy gamma emissions. These advancements open new avenues in low-energy neutrino physics in next-generation LArTPCs.

Figures (20)

• Figure 1: Distribution of multiplicity for final state particles from $\nu_{e}$-Ar CC interactions for incoming $\nu_{e}$ with energy in 5 - 50 MeV following a uniform distribution with mono-energetic spacing.
• Figure 2: Top: Distribution of $E_{\text{avail}}$ and true $E_{\nu_{e}}$ for generated $\nu_{e}$-Ar CC interactions for incoming $\nu_{e}$ with energy in 5 - 50 MeV. Bottom: Fraction of hadron production events as a function of true neutrino energy. Most hadron emission events produce only a neutron (green, $\text{N}_{\text{n}}$ = 1), a proton (red, $\text{N}_{\text{p}}$ = 1), or an alpha particle (pink, $\text{N}_{\alpha}$ = 1). The black line shows the fraction of events with a production of any of the three hadrons.
• Figure 3: Deposited energy distribution for charge (top), light (middle), and combined calorimetry (bottom) for 35 MeV $\nu_{e}$-Ar CC events. In the legend, the energy deposited as charge calorimetry at zero, 75 keV, and 500 keV detection thresholds are denoted as ${Q}_{0}$, ${Q}_{75}$, and ${Q}_{500}$. The energy deposited as light calorimetry under a uniform $\overline{\text{LY}}$ of 220 PE/MeV, 100 PE/MeV, and 35 PE/MeV are denoted as ${L}_{220}$, ${L}_{100}$, and ${L}_{35}$.
• Figure 4: Deposited energy in light assuming $\overline{\text{LY}}$ = 220 PE/MeV for 35 MeV $\nu_{e}$-Ar CC events (purple), overlaid with distribution of events with knockout neutrons (green), protons (red), and $\alpha$s (pink).
• Figure 5: Deposited energy distribution for the 35 MeV $\nu_{e}$-Ar CC sample after excluding energy deposits from neutron captures, overlaid with the relevant inclusive energy distribution in Fig. \ref{['fig:DetectedQL']}. Top: total deposited energy. Middle: energy deposited into charge calorimetry ${Q}_{0}$. Bottom: energy deposited into light calorimetry ${L}_{220}$.