PIKIMO 18, University of Kentucky, 19 April 2025

Session

Morning contributed talks (chairperson R. Hill)

19 Apr 2025, 10:30

153 (Chemistry Physics (CP) Building )

4. Enhancing Solar Neutrino Sensitivity with Neutron Tagging

Obada Nairat (The Ohio State University)

19/04/2025, 10:30

Solar neutrinos provide crucial insights into the Sun’s fusion processes and neutrino oscillations in matter. However, detecting them requires effective suppression of backgrounds. One of these is spallation backgrounds—beta decays of unstable isotopes produced by cosmic-ray muons— which pose a major challenge above 6 MeV. We show that neutron tagging, made possible by the recent addition of...

5. Non-Gaussianity from explicit $U(1)$-breaking interactions

Taegyu Lee (Indiana University)

19/04/2025, 11:00

We investigate primordial non-Gaussianity (NG) that arises from explicit $U(1)$ symmetry-breaking interactions during inflation, focusing on a nearly massless axial component of a complex scalar field $P$. We compute the resulting NG parameter $f_{\mathrm{NL}}$, allowing the axial field to act as either a curvaton or cold dark matter (CDM). We consider two scenarios in which the interaction...

7. Constraining Cosmological Phase Transitions through Curvature Perturbations

Daven Wei Ren Ho

19/04/2025, 11:30

Cosmological first order phase transitions proceed via the random nucleation and expansion of bubbles throughout space. This inherently stochastic process leads to statistical fluctuations across causally disconnected patches from which super-horizon curvature perturbations emerge. I will discuss how such phase transitions generate scalar perturbations that follow a universal power-law scaling...