Neutrino phenomenology in the modular S3 seesaw model

We have studied neutrino phenomenology in the supersymmetric type-I seesaw model endowed with the <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msub><a:mi mathvariant="normal">Γ</a:mi><a:mn>2</a:mn></a:msub><a:mo>≃</a:mo><a:msub><a:mi>S</a:mi><a:mn>3</a:mn></a:msub></a:math> modular symmetry. We have identified different realizations of the <d:math xmlns:d="http://www.w3.org/1998/Math/MathML" display="inline"><d:msub><d:mi>S</d:mi><d:mn>3</d:mn></d:msub></d:math> modular symmetry, referred to as models A, B, C, and D. The four models are compatible with neutrino mass being inverted ordering (IO). Moreover, models A, B, and D can also accommodate normal ordering (NO) neutrino masses. We identify parameter space for each model compatible with neutrino oscillation at the <f:math xmlns:f="http://www.w3.org/1998/Math/MathML" display="inline"><f:mrow><f:mn>2</f:mn><f:mtext>−</f:mtext><f:mi>σ</f:mi></f:mrow></f:math> level. We then proceed to study the neutrino phenomenology of each model. We find that the lightest neutrino mass can be as light as 0.64 meV in the case of NO in model A and 50 meV in the case of IO in model D. The smallest effective electron neutrino mass attainable in our analysis is 8.8 meV in the case of NO (model A) and 50 meV for IO (model D). Finally, we note that the effective Majorana mass can be as small as 0.33 meV in the case of NO (model A) and 22 meV for IO (model D). Published by the American Physical Society 2024