Table of Links
Acknowledgements
1 Introduction to thesis
1.1 History and Evidence
1.2 Facts on dark matter
1.3 Candidates to dark matter
1.4 Dark matter detection
1.5 Outline of the thesis
2 Dark matter through ALP portal and 2.1 Introduction
2.2 Model
2.3 Existing constraints on ALP parameter space
2.4 Dark matter analysis
2.5 Summary
3 A two component dark matter model in a generic 𝑈(1)𝑋 extension of SM and 3.1 Introduction
3.2 Model
3.3 Theoretical and experimental constraints
3.4 Phenomenology of dark matter
3.5 Relic density dependence on 𝑈(1)𝑋 charge 𝑥𝐻
3.6 Summary
4 A pseudo-scalar dark matter case in 𝑈(1)𝑋 extension of SM and 4.1 Introduction
4.2 Model
4.3 Theoretical and experimental constraints
4.4 Dark Matter analysis
4.5 Summary
5 Summary
Appendices
A Standard model
B Friedmann equations
C Type I seasaw mechanism
D Feynman diagrams in two-component DM model
Bibliography
2.5 Summary
We have analyzed heavy neutrino DM candidates in a minimal extension of SM, which features three RHNs and one ALP. This model is well motivated, as it not only accounts for DM but also explains neutrino oscillations. Hence, ALP-mediated RHN DM is interesting from both the model-building and phenomenological perspectives. We have considered the lightest RHN as DM, which is odd under Z2 symmetry, and identified the region of parameters where DM predictions are in agreement with DM relic abundance. In addition, this model also quite naturally explains the null results of LUX and XENON1T due to the pseudoscalar nature of interactions with quarks. We have highlighted the importance of complementary searches, for instance, via indirect detection with single and di-photons. Although the current limits from Fermi-LAT lie above the predicted signals for our choice of parameter space, future sensitivities of Fermi-LAT might offer promising prospects to probe both the low and high DM mass regions.
Author:
(1) Shivam Gola, The Institute of Mathematical Sciences, Chennai.
