This series consists of talks in the areas of Particle Physics, High Energy Physics & Quantum Field Theory.
Direct detection experiments are rapidly improving their sensitivity to weak scale Dark Matter. A particular interesting (and minimal) possibility is that the Dark matter interacts with ordinary matter via the exchange of weak bosons: the W, Z, and Higgs. Dark matter with substantial coupling to the Higgs boson is already under significant tension from limits on spin-independent scattering. We comment on the power of spin-dependent scattering as a probe of Z-mediated dark matter, both in a simple effective theory, and in the so-called Singlet-Doublet Model, which we argue is a useful b
One of the most concrete implications of the discovery of the Higgs boson is that, in the absence of physics beyond the standard model, the long term fate of our universe can now be established through precision calculations. Are we in a metastable minimum of the Higgs potential or the true minimum? If we are in a metastable vacuum, what is its lifetime? To answer these questions, we need to understand tunneling in quantum field theory.
Galaxy clusters represent excellent laboratories to search for Axion-Like Particles (ALPs). They contain magnetic fields which can induce quasi-sinusoidal oscillations in the X-ray spectra of AGNs situated in or behind them. Ultra-deep Chandra observations of the Perseus cluster contain over 5 x 105 counts from the central NGC1275 AGN, and represent an extraordinary dataset for ALP searches. In this talk I will describe how we used these to search for spectral irregularities from the AGN.
Cosmic-ray anti-deuterium and anti-helium have long been suggested as probes of dark matter, as their secondary astrophysical production was thought extremely scarce. But how does one actually predict the secondary flux? Anti-nuclei are dominantly produced in pp collisions, where laboratory cross section data is lacking. We make a new attempt at tackling this problem by appealing to a scaling law of nuclear coalescence with the physical volume of the hadronic emission region. The same volume is probed by Hanbury Brown-Twiss (HBT) two-particle correlations.
Primordial black holes (PBHs) can appear from early Universe dynamics. We show that some or all of heavy element abundance from r-process nucleosynthesis can be produced in interactions of tiny primordial black holes with neutron stars (NSs), if PBHs make up a few percent or more of the dark matter. A PBH captured by a NS will eventually consume it. For a rapidly rotating pulsar, the resulting star spin-up will eject significant amount of cold neutron rich material.
Quantum non-demolition measurements performed using qubit-based artificial atoms may enable the next generation of higher mass dark matter axion search experiments. These QND measurements can precisely determine the amplitude of the photon wave sourced by the dark matter axions while placing the back reaction noise into the phase quadrature.
A permanent non-zero electric dipole moment of the free neutron (nEDM) violates CP-symmetry. The search for an nEDM contributes to understanding the Baryon asymmetry,
as well as it has a high discovery potential for Beyond Standard Model physics. The tool of choice to investigate the nEDM are ultracold neutrons (UCN), since they have such low energies that they can be stored in traps and allow observation times of hundreds of seconds.
Any quantum field theory can be thought of as arising from a perturbed UV conformal field theory, suggesting that information about the full RG flow is encoded in the original CFT. I will discuss ongoing work developing new methods for extracting this information to study strongly-coupled IR dynamics. This method uses a UV basis of conformal Casimir eigenstates to construct the Hamiltonian, which is then truncated at some maximum Casimir eigenvalue and diagonalized to approximate the low energy spectrum of the IR theory.
In the framework of the ordinary seesaw model with right-handed neutrinos (and nothing else) we show that the total lepton number violating decay of the Higgs doublet into a right-handed neutrino and a standard model lepton can successfully account for the baryon asymmetry of the Universe. This is possible thanks to thermal effects shortly before the sphalerons decouple.
We derive in the framework of soft collinear effective field theory (SCET) a Lagrangian describing the t-channel exchange of Glauber quarks, which are incorporated through fermionic potential operators in the effective theory. The Wilson line structure of the operators, which is derived from matching calculations and the symmetries of the effective theory, describe additional soft and collinear emissions from a fermionic t-channel exchange in the forward scattering limit to all orders.