The advent of quantum computation presents the opportunity to solve questions in high energy theory which are inaccessible to classical computation such as real-time evolution and the equation of state at finite density. In order to take advantage of this new resource, a number of theoretical and computational hurdles will need to be addressed.  In this talk, I will discuss the state of the art research being performed in HEP and outstanding questions that require our attention going forward, focusing on digitization of lattice gauge theories and extracting physical results that demonstrate practical quantum advantage.

The ~4σ discrepancy between the experiment and the data-driven theory prediction of the anomalous magnetic moment of the muon is one of the crucial benchmarks to verify the correctness of the standard model. On the lattice QCD side, the Budapest-Marseille-Wuppertal collaboration (BMWc) has a precise full calculation that favors the experimental prediction. Various independent lattice QCD calculations have been done to verify their findings, especially on well-defined ``window quantities'' which suffer fewer lattice artifacts. I will present our lattice calculation of the leading order (LO) hadronic vacuum polarization (HVP) contribution to the muon anomalous magnetic moment for the connected light and strange quarks in the widely used window t0 = 0.4 fm, t1 = 1.0 fm, ∆ = 0.15 fm, and also in the short distance region. We use the overlap fermions on 4 physical-point ensembles. Two 2+1 flavor RBC/UKQCD ensembles use the domain wall fermion (DWF) and Iwasaki gauge actions at a = 0.084 and 0.114 fm, and two 2+1+1 flavor MILC ensembles use the highly improved staggered quark (HISQ) and Symanzik gauge actions at a = 0.088 and 0.121 fm. They have incorporated infinite volume corrections from 3 additional DWF ensembles at L = 4.8, 6.4, and 9.6 fm and physical pion mass. Eventually, our results on the connected light and strange quarks in the widely used window agree with the BMWc findings and other most recent lattice calculations which deviate from the data-driven theory prediction.

Dark matter self interactions can leave distinctive signatures on the properties of satellite galaxies around Milky Way-like hosts. By analyzing a number of Milky Way dwarf galaxies, we were able to place new constraints on models of self-interacting dark matter which interact via a Yukawa potential. The results push the theory into a parameter space with a very specific prediction: self-interactions within satellite galaxies can be either very large (so large that new dynamical effects become important), or very small (so small that such models are usually thought of as collisionless), but not intermediate. Specifically, if self-interactions are large, some dwarfs of the Milky Way must be undergoing a process of gravothermal collapse, and this process has a number of distinct observational predictions which can be searched for in current and upcoming data.

I will present a classification of all unitary, rational conformal field theories with two primaries, central charge c < 25, and arbitrary Wronskian index. These are shown to be either certain level-1 WZW models or cosets of meromorphic theories by such models. By leveraging the existing classification of  meromorphic CFTs of central charge c ≤ 24, all the relevant cosets are enumerated and their characters computed. This leads to 123 theories, most of which are new. It will be emphasised that this is a classification of RCFTs and not just consistent characters. Work in collaboration with Brandon Rayhaun.

This is a joint Theory Seminar/Strings Seminar

It has long been known that smooth crossovers between “Higgs” regimes and “confining” regimes are possible in some gauge theories with fundamental representation matter, leading to a notion of Higgs/confinement “complementarity”.  But the validity, or otherwise, of such complementarity can be subtle, especially in massless phases with Goldstone bosons.  This talk will examine the presence or absence of Higgs/confinement phase transitions, when there are no distinguishing local order parameters, in both instructive models and in dense QCD.

Abstract: The Deep Underground Neutrino Experiment (DUNE) will be the leading next-generation particle project in the US.  It aims to measure CP violation in the neutrino sector and determine the mass ordering of neutrinos.  These measurements are straightforward conceptually but challenging practically.  One outstanding issue is the modeling of GeV neutrino-nucleus interaction.  With a lack of a proper theoretical framework, it is not only difficult to simulate neutrino events in the detector accurately but also difficult to assess its impact on the physics measurements.  I will discuss our attempts at understanding how cross-section uncertainties impact oscillation measurements and new physics searches.

String Theory modifies general relativity with Chern-Simons terms.  In this talk we show how this theory naturally encodes a graviaxion dark matter particle, baryogenesis during cosmic inflation, and leaves imprints on gravitational wave signals in compact binary systems.

After introducing the Taylor expansion method for lattice QCD calculations at non-vanishing baryon chemical potential, I will scrutinize the limitations of the method arising from the presence of Yang-Lee edge singularities in the QCD phase diagram. I will discuss a newly introduced resummation scheme for the Taylor expansion to overcome this limitation and show the efficacy of this scheme using a simple solvable model. I will present some results from realistic lattice QCD calculations utilizing this resummation scheme. I will conclude by introducing a generalized version of the scheme that can resum the recently proposed multi-parameter Taylor expansion.