Description
Chair: James Maxwell
The observations of supernovae can place strong bounds on the couplings of particles beyond the standard model, with masses all the way up to ~200MeV. We study new scalar particles and show that for masses less than the plasma frequency in the supernova core, they are predominantly produced by resonant mixing with an emergent in-medium degree of freedom known as the longitudinal photon. Unlike...
Heavy neutral leptons (HNLs) are constrained by requirements of Big Bang Nu- cleosynthesis (BBN) as their decays significantly impact the formation of the primordial elements. We propose here a model where the primary decay channel for the HNLs is to an axion-like particle (ALP) and a neutrino. Consequently, HNLs can decay earlier and evade the BBN bound for lower masses, provided the ALPs...
The QCD axion, a favourable candidate for dark matter and a solution to the strong CP problem, can efficiently convert into photons in the presence of high magnetic fields. Neutron stars harbour high magnetic fields ($ \approx 10^{12}$ G) and serve as powerful probes to search for axion-photon conversion via observation of radio emission at the axion frequency $\hbar \omega = m_a c^2$, with...
