NEXT ELUSIVES AND INVISIBLESPLUS WEBINAR: “Probing the Neutrino Mass Mechanism with the CMB”

I will present recent work investigating the extent to which the CMB can serve as an indirect probe of neutrino mass models that contain a light neutrino-philic goldstone boson (or bosons). As a specific example I will focus the case where the type-I seesaw mechanism is realized from the spontaneous breaking of a global B-L symmetry, the pseudo goldstone boson here being identified as the majoron. I will show that current observations by Planck allow one to constrain symmetry breaking scales as high as ~ 1 TeV for majoron masses near the ~ eV scale. I will then discuss the current status of the so-called Hubble tension, and show that the present of a light majoron can help ameliorate this outstanding discrepancy.