Strong thermal SO(10)-inspired leptogenesis in the light of recent results from long-baseline neutrino experiments

Abstract

We confront recent experimental results on neutrino mixing parameters with the requirements from strong thermal SO(10)-inspired leptogenesis, where the asymmetry is produced from next-to-lightest right-handed neutrinos N2 independently of the initial conditions. There is a nice agreement with latest global analyses supporting sin δ < 0 and normal ordering at ∼ 95% C.L. On the other hand, the more stringent experimental lower bound on the atmospheric mixing angle starts to corner strong thermal SO(10)-inspired leptogenesis. Prompted and encouraged by this rapid experimental advance, we obtain a precise determination of the allowed region in the plane δ versus θ23. We confirm that for the benchmark case α2 ≡ mD2/mcharm = 5 , where mD2 is the intermediate neutrino Dirac mass setting the N2 mass, and initial pre-existing asymmetry N B −  L p,i  = 10− 3, the bulk of solutions lies in the first octant. Though most of the solutions are found outside the 95% C.L. experimental region, there is still a big allowed fraction that does not require a too fine-tuned choice of the Majorana phases so that the neutrinoless double beta decay effective neutrino mass allowed range is still mee ≃ [10, 30] meV. We also show how the constraints depend on N B −  L p,i and α2. In particular, we show that the current best fit, (θ23, δ) ≃ (47°, −130°), can be reproduced for N B −  L p,i  = 10− 3 and α2 = 6. Such large values for α2 have been recently obtained in a few realistic fits within SO(10)-inspired models. Finally, we also obtain that current neutrino data rule out N B −  L p,i  ≳ 0.1 for α2 ≲ 4.7.

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