High Energy Physics

I will describe ongoing work with Miguel Paulos, Joao Penedones, Jon Toledo and  Balt van Rees. We are attempting to bootstrap massive quantum field theories. 

We formulate a massive S-matrix bootstrap which we analyze both numerically and analytically. We confront our findings with the conformal theory results of lecture 1. We will derive analytic bounds for the couplings in massive 2d QFTs and observe that the Ising field theory with magnetic field lies precisely at the boundary of these bounds.  We conclude with higher dimensional speculations.   

I will describe ongoing work with Miguel Paulos, Joao Penedones, Jon Toledo and  Balt van Rees. We are attempting to bootstrap massive quantum field theories. 

A massive quantum field theory can be put in a large AdS space, i.e. in a box. Its correlators define, as they approach the boundary, a conformal theory. The bootstrap of the latter can pose strong constraints on the former as we will describe. We will then initiate a presentation of the general and of the peculiar features of S-matrices in two dimensions.

The LHCb detector was designed to be the dedicated heavy-flavor physics experiment at the LHC, and has been the world's premier lab for studying processes where the net quark content changes for several years. These studies permit observing virtual contributions from beyond the SM particles up to very high mass scales, potentially (greatly) exceeding the direct reach of the LHC.  I will summarize the constraints placed on high-mass BSM physics by such studies, and also highlight a few interesting anomalies.  I will also discuss direct searches for low-mass BSM physics, and a selection of novel SM studies.  Finally, future prospects will be presented. 

The BPS spectrum of d=4 N=2 field theories in general contains not only hyper and vector-multipelts but also short multiplets of particles with arbitrarily high spin. These BPS states of higher spin reveal quite a peculiar behavior, so sometimes they are called "wild"

states. In this talk we would try to discuss a small refinement of the asymptotic study (spectral network technique) of tt* equations arising in an effective theory on 2d defects in N=2 4d SYM theory capturing spin information and apply it to study some properties of wild BPS spectra.

The vacuum energy changes when cosmological phase transitions take place, or in environments with high temperatures or chemical potentials.  The propagation of primordial gravity waves is affected through the trace anomaly, and eras where the vacuum energy dominates can lead tofeatures in the gravity wave spectrum.  High density phases of QCD in neutron stars, where the vacuum is rearranged, are also a novel probe:  The mass-radius relationships for neutron stars is sensitive to the equation of state appearing in the Einstein equations, which may depend on new dynamics associated with vacuum energy.  Such observations could potentially rule out large classes of explanations for the smallness of the currently observed cosmological constant.

I will present a new area law in General Relativity. This new area law holds on local analogues of event horizons that have an independent thermodynamic significance due to the Bousso bound. I will also discuss a quantum generalization of this more local notion of thermodynamics.

We compute the scaling dimensions of a large class of disorder operators ("monopoles") in the planar limit of CS-fermion theories.  The lightest such operator is shown to have dimension (2/3) k^{3/2}, where k is the CS level.  The computation is based on recently developed techniques for solving CS-matter at all 't Hooft couplings, and the operator dimensions are obtained by finding complex saddles in the low-temperature phase of the CS-fermion path integral in a monopole background.  We will also discuss the implications of this result to 3D bosonization dualities.

We construct a new model of four-dimensional relativistic strings with integrable dynamics on the worldsheet. In addition to translational modes this model contains a single massless pseudoscalar worldsheet field - the worldsheet axion. The axion couples to a topological density which counts the self-intersection number of a string. The corresponding coupling is fixed by integrability to Q=716π−−−√≈0.37. We argue that this model is a member of a larger family of relativistic non-critical integrable string models. This family includes and extends conventional non-critical strings described by the linear dilaton CFT. Intriguingly, recent lattice data in SU(3) and SU(5) gluodynamics reveals the presence of a massive pseudoscalar axion on the worldsheet of confining flux tubes. The value of the corresponding coupling, as determined from the lattice data, is equal to QL≈0.38±0.04.

Some 5d gauge theories have a 6d N=(1,0) SCFT as their UV completion. Given such 5d gauge theory we desire to determine its 6d UV completion. In this talk, I will present a method to do this for 5d gauge theories that can be engineered in string theory by brane webs. This can then be applied to study compactification of 6d N=(1,0) SCFT's on a torus.