Conveners
Parallel 1: DM + GW
- Kenji Nishiwaki (Shiv Nadar Institute of Eminence)
Description
DM + GW
In an effective field theory approach, we have considered a minimal extension of Standard Model is extended by a non-renormalizable dimension six operator of the form respecting the symmetries of the Standard Model. Such an operator can affect the dynamics of Higgs field and the electroweak phase transition. Presence of such term modifies the triple Higgs coupling. Constraint on the scale...
We propose a novel and comprehensive particle physics framework that addresses multiple cosmological tensions observed in recent measurements of the Hubble parameter, $S_8$, and Lyman-$\alpha$ forest data. Our model, termed `{SIDR+z_t}' (Self Interacting Dark Radiation with transition redshift), is based on an inelastic dark matter (IDM) scenario coupled with dark radiation, governed by a...
The singlet-doublet vector-like fermion dark matter model has been extensively studied in the literature over the past decade. An important parameter in this model is the singlet-doublet mixing angle ($\sin\theta$). All the previous studies have primarily focused on annihilation and co-annihilation processes for obtaining the correct dark matter relic density, assuming that the singlet and...
The singlet-doublet dark matter model is one of the most studied WIMP scenarios to realize the relic of DM in a large parameter space. In this work, we study the two-step leptogenesis in the singlet-doublet Majorana dark matter model. We extend the Standard Model (SM) by introducing three Majorana singlet fermions ($N_i$), three doublet fermions ($\Psi_i$), and a singlet scalar ($\Phi$), all...
We propose a GeV-scale self-interacting dark matter (SIDM) candidate within a $U(1)_D$ extension of the Standard Model (SM), addressing small-scale structure anomalies in $\Lambda$CDM while predicting an observable contribution to $\Delta N_{\rm eff}$. The model introduces a fermionic DM candidate $\chi$ and a scalar $\phi$, both charged under an unbroken $U(1)_D$ gauge symmetry. The...
