A5091148061- Particle physics theoretical and experimental studies
- Dark Matter and Cosmic Phenomena
- Cosmology and Gravitation Theories
- Galaxies: Formation, Evolution, Phenomena
- Particle Detector Development and Performance
- Neutrino Physics Research
- Computational Physics and Python Applications
- Physics of Superconductivity and Magnetism
- Magnetic properties of thin films
- Advanced Condensed Matter Physics
- Black Holes and Theoretical Physics
Chungnam National University
2024
Indian Association for the Cultivation of Science
2020-2023
Sogang University
2022
Non-observation of any dark matter signature at various direct detection experiments over the last decade keeps indicating that immensely popular WIMP paradigm may not be actual theory particle matter. Non-thermal produced through freeze-in is an attractive proposal, naturally explaining null results by virtue its feeble couplings with Standard Model (SM) particles. We consider a minimal extension SM two gauge singlet fields namely, 2-odd fermion χ and pseudo scalar ̃ϕ, where former has...
We estimate the big bang nucleosynthesis (BBN) constraint on majoron in mass range between 1 MeV to 10 GeV which dominantly decays into standard model neutrinos. When Majoron lifetime is shorter than sec, injected neutrinos mainly heat up background plasma, alters relation photon temperature and neutrino temperature. For a longer most of directly contribute protons-to-neutrons conversion. In both cases, deuterium helium abundances are enhanced, while from stronger that helium. <a:math...
Abstract In secluded dark sector scenario, the connection between visible and can be established through a portal coupling its presence opens up possibility of non-adiabatic evolution sector. To study sector, we have considered U(1) L μ – τ ⊗ X extension standard model (SM). Here is charged only under gauge symmetry whereas SM fields are singlet this symmetry. Due to tree-level kinetic mixing bosons, evolves non-adiabatically thermal equilibrium governed by coupling. Depending on values (ϵ),...
New light species can contribute to the number of effective relativistic degrees freedom (Neff) at Cosmic Microwave Background (CMB) which is precisely measured by Planck. In this work, we consider an MeV scale thermally decoupled non-minimal dark sector and study imprint dynamics on measurement Neff time CMB formation. We have predicted allowed region model parameter space in constraints arising from measurements both matter relic density It turns out that impact significant case a...
Abstract The lack of information before Big Bang Neucleosynthesis (BBN) allow us to assume the presence a new species ϕ whose energy density redshifts as -4+ n where > 0 and is scale factor. This non-standard cosmological setup facilitates larger portal coupling ( ϵ ) between dark visible sectors even when two are not in thermal equilibrium. Here, we have considered U(1) L μ -L τ ⊗ X gauge extension Standard Model (SM) studied different phases evolution thermally decoupled sector such...
Received 21 March 2014DOI:https://doi.org/10.1103/PhysRevLett.112.139903© 2014 American Physical Society
A bstract Exponential suppression or commonly known as the Boltzmann in number density of dark matter is key ingredient for creating chemical imbalance prior to usual thermal freeze-out. degenerate/quasi-degenerate sector can experience a different exponential analogous radioactive decay law leading delayed freeze-out mechanism co-decaying matter. In this work, we study dynamics multicomponent from thermally decoupled degenerate hidden U(1) X extension Standard Model. We compute relic...
We investigate the dark matter (DM) phenomenology of axion-like particles (ALP) along with ALP interpretation muon $(g-2)$ in a minimal extension Standard Model (SM). Here we have considered flavor dependent couplings SM leptons to study allowed region parameter space from measurement, taking into account all possible one and two loop diagrams. found that certain can act as DM, satisfying constraint other experimental bounds. From our relic density calculation, infer DM candidate mass range...
The lack of information before Big Bang Neucleosynthesis (BBN) allow us to assume the presence a new species $ϕ$ whose energy density redshifts as $a^{-(4+n)}$ where $n>0$ and $a$ is scale factor. This non-standard cosmological setup facilitates larger portal coupling $(ε)$ between dark visible sectors even when two are not in thermal equilibrium. Here, we have considered $U(1)_{L_μ-L_τ}\otimes U(1)_X$ gauge extension Standard Model (SM) studied different phases evolution thermally...
The well-known Boltzmann suppression is the key ingredient to create chemical imbalance for thermal dark matter. In a degenerate/quasi-degenerate sector can also be generated from different mechanism which analogous radioactive decay law, known as co-decaying this work, we have studied dynamics of multicomponent thermally decoupled degenerate in hidden $U(1)_X$ extension Standard Model. We compute relic density and temperature ($T^\prime$) evolution by considering all possible...