This series consists of talks in the areas of Particle Physics, High Energy Physics & Quantum Field Theory.
Two uncertainties define the prevailing attitude toward the LHC: uncertainty about what new physics it may find (if any); together with dissatisfaction with the "technical naturalness" arguments which (when applied to the hierarchy problem) help suggest what it should be looking for. The dissatisfaction arises because of a wide-spread despair about finding a technically natural solution to the cosmological constant problem, despite much effort spent seeking it.
I will discuss cosmological, astrophysical and collider constraints on thermal dark matter with mass in the range 1 MeV to 10 GeV. CMB observations can be evaded if the DM relic density is sufficiently asymmetric, while collider constraints generally require sufficiently light mediators. These light mediators can give rise to significant DM self-interactions, and I will describe bounds on such interactions from dark matter halo shapes.
We propose that the fermionic superpartner of a weak-scale Goldstone boson can be a nat- ural WIMP candidate. The p-wave annihilation of this `Goldstone fermion' into pairs of Gold- stone bosons automatically generates the correct relic abundance, whereas the XENON100 direct detection bounds are evaded due to suppressed couplings to the Standard Model. Further, it is able to avoid indirect detection constraints because the relevant s-wave annihi- lations are small. The interactions of the Goldstone supermultiplet can induce non-standard Higgs decays and novel collider phenomenology.
We show that a baryon asymmetry can be generated by dissipative effects during warm inflation via a supersymmetric two-stage mechanism, where the inflaton is coupled to heavy mediator fields that then decay into light species through B- and CP-violating interactions. In contrast with thermal GUT baryogenesis models, the temperature during inflation is always below the heavy mass threshold, simultaneously suppressing thermal and quantum corrections to the inflaton potential and the production of dangerous GUT relics.
Both Tevatron experiments have recently reported an anomalous forward-backward asymmetry in top-antitop production. Their inclusive results are roughly 3 standard deviations larger than the standard model prediction and may be evidence of new physics that couples to the top quark. In this talk, I will present a weakly-coupled light axigluon model (
In massive gravity the so-far-found black hole solutions on Minkowski space happen to convert horizons into a certain type of singularities. I will discuss whether these singularities can be avoided if space-time is not asymptotically Minkowskian.
In this talk, I will discuss various aspects of UV-complete R-symmetric QFTs. In particular, I will focus on a small set of operators that are well-defined in many such theories, and I will argue that one can use these operators to get a (partial) non-perturbative handle on the deep IR physics, including, possibly, a handle on certain aspects of the emergent symmetries. Throughout, I will highlight applications to particle physics.
The full machinery of supergravity (SUGRA) is required to fully understand many supersymmetric models. For the purpose of understanding phenomenology at colliders and in cosmology, the main concern is to ascertain the effects of SUGRA on the vacuum structure and particle spectrum. Practical calculations often require cumbersome manipulations of component field terms involving the full gravity multiplet. In this talk I will present an alternative gauge fixing for conformal SUGRA which decouples these gravity complications from SUGRA computations.