Chandrasekhar Hall

A Relation Between Dark Matter and Leptogenesis, and Neutrino Mass in light of current experimental bounds

Nimmala Narendra

IIT-Hyderabad

After the Higgs discovery in 2012, the Standard Model (SM) of particle physics provides the best framework of elementary particles and their interactions in nature. However, there are a plethora of unsolved problems yet exist. Among them, the most interesting are Dark Matter (DM), Baryon asymmetry of the Universe and smallness of the neutrino mass. Over the last decades, cosmology gathered evidences against DM on a galactic scale and larger. In fact, the satellite borne experiments WMAP and Planck, which probe the temperature fluctuations in the cosmic microwave background, precisely measure the relic density of DM to be about 26.8 % of the total energy budget of the Universe. Moreover, these experiments show that the visible matter is about (1/5)th of the DM content of the Universe. Interestingly we never see any antimatter in the present Universe, even though the Universe created with equally matter and antimatter. This problem is currently posed as Baryon asymmetry and is precisely calculated by WMAP and Planck to be n_B /n_γ ≈ 6.6 × 10^−10. Another missing piece of the SM is the non-zero but small masses of neutrinos, which are required by the oscillation experiments, such as SNO, T2K. An attempt is made to solve the above said phenomena simultaneously in a single framework by extending the SM by introducing new particles and/or symmetry, while they are consistent with the current experimental bounds. In my talk, I will discuss two models which explain the above said problems.