Speaker: Zhen Liu
Title: The Hunt for Gluonic ALPs
Room: 3024
Zoom: https://zoom.us/j/186024391
Host: Da Liu
Abstract:
Axion coupling to gluons is the defining property that connects it to the Strong CP puzzle. People have recently started to consider heavier axions, often dubbed Axion-Like-Particles (ALPs), as a generic EFT for pseudo-scalars. However, the effects have mostly been focused on other couplings as they are much easier to calculate and observe. In this talk, I will describe the attempt to consider Strong-CP solving heavy axions that beneficially are more stable potential against Planck suppressed perturbations. The axion mass and potential receive reinforcement from a mirror sector. Then, I will describe a class of searches motivated by this consideration and the generic considerations for gluonic ALPs. The searches for such gluonic heavy axions are challenging due to the typical large QCD background. New search ideas, projections, and results at the LHC, FASER/FPF, DUNE, and ArgoNeuT will be presented.
Description:
Cinco de Mayo
Description:
Mother's Day
User:
High-Energy Seminars
Time:
1:30pm - 3:00pm
Description:
Speaker: David Curtin
Title: Complex Dark Matter Dynamics
Room: 3024
Zoom: https://zoom.us/j/186024391
Host: Da Liu
Abstract:
I will discuss the theoretical motivation and possible signatures of atomic dark matter and similar complex dark sectors. These are theoretically motivated by solutions to the hierarchy problem that relate the dark sector to the SM by a discrete symmetry, like the Twin Higgs, and lead to a large variety of potentially striking signatures on cosmological and astrophysical scales. Mirror stars shining in dark photons are a generic prediction, but they may be observable in telscope surveys if a small kinetic mixing between the dark and visible photon is present, which enables these exotic objects to capture and excite SM matter in their cores. Mirror Neutron stars can be detected at LIGO, microlensing experiments can search for dark disks, and electron recoil direct detection experiments are sensitive to atomic dark matter and its dark plasma effects near the Earth due to capture. While significant recent progress has been made to understand these signatures, tying them together requires a robust understanding of complex dark matter dynamics on cosmological and galactic scale. To this end, I will give a preview of our current research program to obtain precision cosmological bounds on atomic dark matter, and use full magneto-hydrodynamical N-body simulations to include their effects on the evolution of our Milky Way.
User:
High-Energy Seminars
Time:
1:30pm - 3:00pm
Description:
Speaker: Gustavo Marques Tavares
Title: Precision early universe cosmology from gravitational waves
Room: 3024
Zoom: https://zoom.us/j/186024391
Host: Luty
Abstract: Gravitational waves have opened a new window into the early universe. Due to their small interactions, gravitational waves can travel effectively freely to us, carrying information from early stages of the universe, when temperatures and densities were much larger than what can be achieved in laboratories. In this talk, I will first show that for gravitational wave sources that only operate during a small finite time, the low frequency spectral shape of the waves is fixed by causality and, hence, independent of details of the source. Furthermore, their spectral shape encodes information about the equation of state of the universe, and also about the presence of free-streaming radiation. This makes gravitational waves a powerful tool to study early universe cosmology. In the second part of the talk, I will explore a number of motivated scenarios beyond the standard model that could be tested with future gravitational wave instruments, if we detect a sufficiently strong stochastic gravitational wave signal.
User:
High-Energy Seminars
Time:
1:00pm - 2:00pm
Send Reminder:
Yes - 0 days 4 hour 0 minutes before start
Description:
TEST EVENT - main repeating event
User:
High-Energy Seminars
Time:
1:30pm - 3:00pm
Description:
Speaker: Raymond Co
Title: Gravitational Wave Probes of Axion Rotations Responsible for Dark Matter and Baryon Asymmetry
Room: 3024
Zoom: https://zoom.us/j/186024391
Host: Da Liu
Abstract:
We established a paradigm where the (QCD) axion’s novel cosmological evolution, a rotation in the field space, gives rise to dark matter and the baryon asymmetry. The axion rotations also provide a natural origin for a kination era, where the total energy density is dominated by the kinetic term of the axion field, preceded by an early era of matter domination. We investigate the effects of this cosmological scenario on the spectrum of possible primordial gravitational waves from inflation or cosmic strings and find that the spectrum features a triangular peak. As a result, future gravitational wave observations can probe the viable parameter space of kination, including regions that produce axion dark matter by the kinetic misalignment mechanism or the baryon asymmetry by axiogenesis. Lastly, the axion rotation may also source the cosmic perturbations with an observable amount of non-Gaussianity.
