Feasibility of a directional solar neutrino measurement with the CYGNO/INITIUM experiment

The CYGNO project aims to develop a gaseous high- precision Time Projection Chamber with an optical readout for directional Dark Matter searches and solar neutrino spectroscopy. CYGNO incorporates innovative features, such as the utilization of a He-CF₄ scintillating gas mixture, at atmospheric pressure and room temperature, together with a triple GEM amplification system optically readout by PMTs and sCMOS cameras. By combining the information of the high-granularity camera with the fast sampling of the PMT, it is possible to perform 3D tracking with head-tail capability and particle identification down to O(keV) energy. The ERC project INITIUM, in synergy with CYGNO, aims to develop negative ion drift operations within the CYGNO 3D optical approach. Directional DM detectors, as high precision gaseous TPCs, are not only able to discriminate solar neutrino interacting through Coherent Elastic Neutrino-Nucleus Scattering (CEvS) from a DM signal but even better, to promote neutrino from an inconvenience to a physics case. Directionality can indeed be exploited not only on Nuclear Recoils induced by CEvNES but also on electron recoil generated by the elastic scattering of O(10- 100) keV neutrinos on the target atomic electrons. With a TPC, it is possible to well identify the signal induced by solar neutrino from the Sun by reconstructing the electron recoil initial direction. The angular distribution of these ER will show a peak in the opposite direction of the Sun (produced by neutrinos) over a flat background component. Due to the relatively low gas density, which determines a low multiple scattering, electron direction reconstruction is feasible even at energies as low as a few tens of keV, corresponding to an approximate 60 keV threshold on neutrino energy.  In this talk, we will show the latest results of the CYGNO experiment prototypes and R&Ds, with a particular focus on the overground commissioning of the LIME detector, with a 33x33 cm² readout area, and a drift length of 50 cm. We will illustrate the MC simulation of the sCMOS images, tuned using a dedicated data set, and the comparison between these and real data acquired with LIME exposed to multiple X-ray sources. We will demonstrate the robust data/MC agreement achieved by this, not only in energy linearity and resolution but also on multiple track shape variables. Next, we will demonstrate the capability to reconstruct the initial direction of low-energy electron recoil using simulated data. Finally, we will illustrate the prospects for solar neutrino spectroscopy with a CYGNO 30 m³ detector by illustrating the expected sensitivity to the measurement of neutrino from the solar pp cycle down to O(50) keV neutrino energy obtained within a Bayesian statistical framework.

Zoom: https://dipc-org.zoom.us/j/97170177298
Youtube: https://youtube.com/live/azQ0ReW_BMM