Conveners
Theoretical Developments & Extra Dimensions
- Keith Dienes (University of Arizona)
The notion of stringy naturalness-- that an observable $O_2$ is more natural than $O_1$ if more (phenomenologically acceptable) vacua solutions lead to
$O_2$ rather than $O_1$-- is examined within the context of the Standard Model (SM) and various SUSY extensions: CMSSM/mSUGRA, high-scale SUSY and radiatively-driven natural SUSY (RNS). Rather general arguments from string theory suggest a...
In this talk, I will briefly introduce the scenario of asymptotically safe quantum gravity as a UV complete description of nature. In particular, I will focus on the enhanced predictive power coming along with the existence of an interacting UV fixed point of quantum gravity and matter. This allows to predict the IR values of some standard-model couplings, and might even give rise to a...
In this talk we make a case for considering alternatives to the Bunch-Davies vacuum state for quantizing inflaton perturbations. The choice of vacuum state of a (free) quantum field theory in a generic (spatially flat) Friedmann-Robertson-Walker spacetime is unavoidably ambiguous, with two physically viable vacua potentially behaving drastically differently at small momentum. We consider a...
We propose an on-shell viewpoint of the effective field theories (EFT), which treats effective operators as local on-shell amplitudes. As building blocks of an effective theory, both the operator basis and the amplitude basis should contain the same amount of information. In this talk, I will briefly introduce two benefits this viewpoint bring to us. First, we can translate some obvious...
We point out that the states required by the Lattice Weak Gravity Conjecture, along with certain genericity conditions, imply the existence of non-vanishing kinetic mixing between massless Abelian gauge groups in the low-energy effective theory. We begin with an estimate using a lattice of states satisfying the WGC up to some coefficients of order unity. We refine our estimate by considering a...
We analyze signals arising from production and subsequent decay of Kaluza-Klein (KK) gravitons in the extended warped extra dimensional models at the LHC. In these models, the extra dimensional bulk is divided into two regions: (i) from the Planck/UV brane to an O(10 TeV) middle brane, and (ii) from the middle brane to an O(TeV) IR brane. The standard model (SM) fermions and Higgs only...
The extended warped model predicts two 4-jet signals produced by KK graviton decay: (1) KK graviton decay to two radions, which each dominantly decay to two (SM gluon) jets, and (2) KK graviton decay to KK gluon and (SM gluon) jet, followed by KK gluon to radion and (SM gluon) jet, followed by radion to two jets. We analyze two parts of the model's parameter space at 14 TeV HL-LHC...
If large enough extra dimensions exist, the fundamental gravity scale may be as low as a few TeV to allow for the production of microscopic black holes in collisions of high energy particles. Cosmic neutrinos may reach the energy up to tens of EeV, which translates to the center of mass energy of more than 100TeV in neutrino-nucleon scattering, rendering the next generation of neutrino...
