Research Interests

My one true love is non-perturbative physics, and as such my research interests span a wide range of topics within particle theory, including thermal field theory, false vacuum decay + phase transitions, QCD + collider phenomenology, and baryogenesis.


Non-perturbative Methods for False Vacuum Decay [arXiv:2104.10687]

with Thomas Konstandin, Robert McGehee, and Hitoshi Murayama

Abstract: We propose a simple non-perturbative formalism for false vacuum decay using functional methods. We introduce the quasi-stationary effective action, a bounce action that non-perturbatively incorporates radiative corrections and is robust to strong couplings. The quasi-stationary effective action obeys an exact flow equation in a modified functional renormalization group with a motivated regulator functional. We demonstrate the use of this formalism in a simple toy model and compare our result with that obtained in perturbation theory.

Asymmetric Matters from a Dark First-Order Phase Transition [arXiv:1911.12342]

with Thomas Konstandin, Robert McGehee, and Hitoshi Murayama

Abstract: We introduce a model for matters-genesis in which both the baryonic and dark matter asymmetries originate from a first-order phase transition in a dark sector with an SU(3)×SU(2)×U(1) gauge group and minimal matter content. In the simplest scenario, we predict that dark matter is a dark neutron with mass either mn=1.33 GeV or mn=1.58 GeV. Alternatively, dark matter may be comprised of equal numbers of dark protons and pions. This model, in either scenario, is highly discoverable through both dark matter direct detection and dark photon search experiments. The strong dark matter self interactions may ameliorate small-scale structure problems, while the strongly first-order phase transition may be confirmed at future gravitational wave observatories.

Baryogenesis From a Dark First-Order Phase Transition [arXiv:1910.08068]

with Thomas Konstandin, Robert McGehee, Hitoshi Murayama, and Géraldine Servant

Abstract: We present a very minimal model for baryogenesis by a dark first-order phase transition. It employs a new dark SU(2)D gauge group with two doublet Higgs bosons, two lepton doublets, and two singlets. The singlets act as a neutrino portal that transfer the generated asymmetry to the Standard Model. The model predicts exotic decays of the Higgs and Z bosons, ΔNeff = 0.09-0.13, and stochastic gravitational waves, all detectable by future experiments.

Photon Isolation and Jet Substucture [arXiv:1805.11622]

with Jesse Thaler

Abstract: We introduce soft drop isolation, a new photon isolation criterion inspired by jet substructure techniques. Soft drop isolation is collinear safe and is equivalent to Frixione isolation at leading non-trivial order in the small R limit. However, soft drop isolation has the interesting feature of being democratic, meaning that photons can be treated equivalently to hadrons for initial jet clustering. Taking advantage of this democratic property, we define an isolated photon subjet: a photon that is not isolated from its parent jet but is isolated within its parent subjet after soft drop declustering. The kinematics of this isolated photon subjet can be used to expose the QED splitting function, in which a quark radiates a photon, and we verify this behavior using both a parton shower generator and a perturbative calculation in the collinear limit.