Nuclear Physics Seminar with Supriya Senapati on Exploring Alternative Left-Right Model: 0νββ decay and Leptogenesis

Left-Right (LR) theories are one of the successful beyond Standard Model scenarios to provide a unified explanation to the origin of small neutrino masses and low-energy parity violation. However, conventional LR theory faces stringent constraints due to Flavor Changing Neutral Currents (FCNCs). We have explored an Alternative LR model (ALRM) that avoids FCNC constraints and introduces new physics signatures in 0νββ decay and leptogenesis. We have shown that the new type of vector-scalar diagram contributes significantly in 0νββ decay. When the relevant charged Higgs boson has mass around 200 GeV, the half-life of decaying nucleus is approximately 1026 years for both 76Ge and 136Xe, which falls well within the anticipated sensitivity of future 0νββ experiments. Moreover, this model has the potential to explain the correct baryogengesis, even in the presence of small Dirac CP phase in right-handed neutrino sector and without requiring any more fine-tuning, by invoking the resonant leptognesis.

This lecture was made possible by the William C. Ferguson fund.