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Opportunities and challenges to study solar neutrinos with a Q-Pix pixel readout

M. Á. García-Peris1,*, G. Ruiz1, S. Kubota1,2,3, A. Navrer-Agasson4, G. V. Stenico5, E. Gramellini1, R. Guenette1, J. Asaadi6, J. B. R. Battat7 et al.

V. A. Chirayath6, E. Church8, Z. Djurcic9, A. C. Ezeribe10, J. N. Gainer6, G. Gansle6, K. Keefe6, N. Lane1, C. Mauger11, Y. Mei6, F. M. Newcomer11, D. R. Nygren6, M. Rooks6, P. Sau6, O. Seidel6, S. Söldner-Rembold4, I. Tzoka6, and R. Van Berg11

  • *Contact author: miguel.garciaperis@manchester.ac.uk
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Phys. Rev. D 112, 092009 – Published 17 November, 2025

DOI: https://doi.org/10.1103/xq7l-lv7j

Abstract

The study of solar neutrinos presents significant opportunities in astrophysics, nuclear physics, and particle physics. However, the low-energy nature of these neutrinos introduces considerable challenges to isolate them from background events, requiring detectors with low-energy threshold, high spatial and energy resolutions, and low data rate. We present the study of solar neutrinos with a kiloton-scale liquid argon detector located underground, instrumented with a pixel readout using the Q-Pix technology. We explore the potential of using volume fiducialization, directional topological information, light signal coincidence, and pulse-shape discrimination to enhance solar neutrino sensitivity. We find that discriminating neutrino signals below 5 MeV is very difficult. However, we show that these methods are useful for the detection of solar neutrinos when external backgrounds are sufficiently understood and when the detector is built using low-background techniques. When building a workable background model for this study, we identify γ background from the cavern walls and from capture of α particles in radon decay chains as both critical to solar neutrino sensitivity and significantly underconstrained by existing measurements. Finally, we highlight that the main advantage of the use of Q-Pix for solar neutrino studies lies in its ability to enable the continuous readout of all low-energy events with minimal data rates and manageable storage for further off-line analyses.

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Phys. Rev. D 112, 092009– Published 17 November, 2025
  • Received 24 July 2025
  • Accepted 22 October 2025
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