Solar neutrinos provide crucial insights into the Sun’s fusion processes and neutrino oscillations in matter. However, detecting them requires effective suppression of backgrounds. One of these is spallation backgrounds—beta decays of unstable isotopes produced by cosmic-ray muons— which pose a major challenge above 6 MeV. We show that neutron tagging, made possible by the recent addition of...
We investigate primordial non-Gaussianity (NG) that arises from explicit $U(1)$ symmetry-breaking interactions during inflation, focusing on a nearly massless axial component of a complex scalar field $P$. We compute the resulting NG parameter $f_{\mathrm{NL}}$, allowing the axial field to act as either a curvaton or cold dark matter (CDM). We consider two scenarios in which the interaction...
