• Anirban Biswas

Articles written in Pramana – Journal of Physics

• Real gauge singlet scalar extension of the Standard Model: A possible candidate for cold dark matter

The simplest extension of Standard Model (SM) is considered in which a real SM gauge singlet scalar with an additional discrete symmetry $Z_{2}$ is introduced to SM. This additional scalar can be a viable candidate of cold dark matter (CDM) since the stability of 𝑆 is achieved by the application of $Z_{2}$ symmetry on 𝑆. Considering 𝑆 as a possible candidate of CDM, Boltzmann’s equation is solved to find the freeze-out temperature and relic density of 𝑆 for Higgs mass 120 GeV in the scalar mass range 5 GeV to 1 TeV. As HHSS coupling $\delta_{2}$ appearing in Lagrangian depends upon the value of scalar mass $m_{S}$ and Higgs mass $m_{h}$, the $m_{S} − \delta_{2}$ parameter space has been constrained by using the Wilkinson microwave anisotropy probe (WMAP) limit on the relic density of DM in the Universe and the results of recent ongoing DM direct search experiments, namely CDMS-II, CoGeNT, DAMA, EDELWEISS-II, XENON-10 and XENON-100. From such analyses, two distinct mass regions are found (a lower and higher mass domain) for such a DM candidate that satisfy both the WMAP limit and the experimental results considered here. The possible differential direct detection rates and annual variation of total detection rates have been estimated for this scalar DM candidate 𝑆 for two detector materials, namely Ge and Xe. Finally, the 𝛾-ray flux has been calculated from the galactic centre due to annihilation of two 130 GeV scalar DM into two monoenergetic 𝛾-rays.

• Exploring a hidden fermionic dark sector

We propose a hidden sector fermion dark matter model which follows a dark $SU(2)_H$ symmetry. Fermions in the dark sector also carry a global $U(1)_H$ charge while the gauge bosons and dark scalar do not have any global $U(1)_H$ charge. The lightest fermion in dark sector can serve as a potential dark matter candidate. We investigate whether the proposed dark matter candidate can explain indirect detection results from galactic centre.

• # Pramana – Journal of Physics

Current Issue
Volume 93 | Issue 6
December 2019

• # Editorial Note on Continuous Article Publication

Posted on July 25, 2019