• Nuclear, Particle, Astroparticle and Cosmology (NUPAC) Seminars

November 12, 2024 2:00 PM - November 12, 2024 3:00 PM

Host:

Francis-Yan Cyr-Racine

Presenter:

Dr. Yu-Dai Tsai (LANL)

Exploring millicharged particles (particles with small rational or irrational charges) has become a central topic in particle physics and cosmology. Linked to charge quantization, which spurred Dirac Quantization and Grand Unification Theories, the millicharge search is a testing ground for string theory and quantum gravity.

I will give a general introduction to millicharged particles and present a novel approach to leverage them for probing reheating cosmology—a pivotal phase post-inflation, shaping the current Universe's particle composition. Millicharge searches offer insights into reheating scenarios and temperatures. I will also discuss the irreducible cosmic millicharged background and implications on the dark matter observations, the 21-cm absorption spectrums, Big Bang nucleosynthesis (BBN), and CMB measurements.

Finally, the talk delves into dedicated experimental efforts, notably the FORMOSA and SHiP experiments at CERN, neutrino experiments (including MicroBooNE, ArgonCube 2x2, DUNE) at Fermilab, and LANSCE-mQ at LANL, which will help unveil the mysteries in cosmology and fundamental theories.