This series consists of talks in the areas of Particle Physics, High Energy Physics & Quantum Field Theory.
The Enriched Xenon Observatory (EXO) collaboration has observed the two-neutrino double beta decay of 136Xe with EXO-200, a prototype to the full EXO detector in development. This second order process, predicted by the Standard Model, has been observed for several nuclei but not for 136Xe. The observed decay rate provides new input to matrix element calculations and to the search for the more interesting neutrino-less double-beta decay, the most sensitive probe for the existence of Majorana particles and the measurement of the neutrino mass scale.
The simplest technicolor model contains would-be Goldstone bosons to provide masses for the observed W and Z particles, replacing the standard Higgs mechanism. Perhaps surprisingly, it also contains an additional Goldstone boson that is a natural dark matter candidate. A recent lattice simulation has confirmed the symmetry-breaking pattern, explored the mass spectrum of the lightest technihadrons, and established an effective field theory.
The 7 TeV LHC run has the potential to shed light on extensions beyond the Standard Model. I will discuss the prospects for finding new colored particles in an optimistic signature for discovery, heavy flavor jets and missing energy. I will illustrate the use of Simplified Models in guiding the organization of searches and presentation of results. Finally, I will discuss finer jet observables, and their possible applications in understanding Standard Model backgrounds and distinguishing new physics in a jet-rich environment.
We suggest the existence of a fundamental connection between baryonic and dark matter. This is motivated by both the stability of these two types of matter as well as the observed similarity of their present-day densities. A unified genesis of baryonic and dark matter arises naturally in models in which proton stability is ensured by promoting the baryon number to a local symmetry. This is illustrated in a specific class of SUSY models using the Affleck-Dine mechanism.
The hierarchy of the Yukawa couplings is an outstanding problem of the standard model. We present a class of models in which the first and second generation fermions are SUSY partners of pseudo-Nambu-Goldstone bosons that parameterize an E_7/SO(10) Kahler manifold, explaining the small values of these fermion masses relative to those of the third generation. We consider experimental constraints on this scenario, and find that the simplest model with universal gaugino masses is already ruled out by the LHC.
The observed conservation of Baryon and Lepton number may arise because they are gauge symmetries. Models are discussed where Baryon and lepton number are the charges for a spontaneously broken U(1) gauge symmetries. The best of these models is: (1) free of Landau poles that are near the weak scale, (2) has no flavor changing neutral currents at tree level and (3) contains a dark matter candidate.
Recently, several neutrino physics has witnessed an accumulation of anomalous results. In the first part of this talk, we will discuss the tension that the MINOS experiments has seen between oscillations of neutrinos and anti-neutrinos. We will show that, phenomenologically, this tension can be explained if neutrinos are hypothesized to have new interactions mediated by higher-dimensional operators, but we will also show that problems arise when one attempts to embed these operators into renormalizable models.
Unexplained hierarchies and the quest for naturalness have driven model-building efforts in particle physics and cosmology for the past few decades. I will speak about various approaches to problems of 'unnatural'
fine tunings, in the context of supersymmetry, inflation and LHC phenomenology respectively.
It is often assumed that the first evidence for direct dark matter detection will come from experiments probing spin-independent interactions, because of higher sensitivities due to coherence effects. We explore the possibility of models that would be invisible in such experiments, but detectable via spin-dependent interactions. The existence of much larger (or only) spin-dependent tree-level interactions is not sufficient, due to potential spin-independent subdominant or loop-induced interactions.