This series consists of talks in the areas of Particle Physics, High Energy Physics & Quantum Field Theory.
Light third generation
superpartners are one way to avoid bounds on new physics from the early
LHC. We will review the theory and phenomenology of light stops and highlight a
particular UV model based a partially composite electroweak sector through
We present new results on the performance of jet substructure techniques
and their use in distinguishing the signatures of new boosted massive particles
from the QCD background. Advanced approaches to jet reconstruction using jet
grooming algorithms such as filtering, trimming, and pruning are compared.
Measurements of the jet invariant mass for each jet algorithm are compared both
at the particle level to multiple Monte Carlo event generators and at the
detector level for several configurations of the jet grooming algorithms.
With the discovery of a new Higgs-like particle at the LHC, there is an
unprecedented opportunity to use the Higgs as a probe for physics beyond the
Standard Model. I will discuss a variety of recent ideas to look for new
physics via the Higgs, including measurements of Higgs couplings and associated
indirect observables; searches for Higgs production in association with new
physics; and strategies for probing extended electroweak symmetry breaking
phenomenological Minimal Supersymmetric Standard Model (pMSSM) provides a broad
perspective on supersymmetric phenomenology. We have generated two large sets
of pMSSM models with neutralino and gravitino LSPs, with sparticle masses
extending up to 4 TeV. In this talk, I will discuss the implications of
searches for supersymmetry and the Higgs, with particular attention to
naturalness. In particular, we find that while sparticle spectra with
moderately light stops are still allowed, such stops are difficult to find
The LHC detectors are allowing experimentalists to look
"inside" of jets and study the properties of these. Jet substructure
gives us the tools to study boosted resonances that decay into jets. In
this talk, I will discuss an extension of substructure techniques to beyond the
Standard Model signals where reconstructing resonances may not be optimal, but
these techniques still allow us to pick out these signals from a busy QCD
Precision timepieces are marvels of human ingenuity. Over the past half-a-century, precision time-keeping has been carried out with atomic clocks. I will review a novel and rapidly developing class of atomic clocks, optical lattice clocks. At their projected accuracy level, these would neither lose nor gain a fraction of a second over estimated age of the Universe. In other words, if someone were to build such a clock at the Big Bang and if such a timepiece were to survive the 14 billion years, the clock would be off by no more than a mere second.
A beautiful understanding of the smallness of the neutrino masses may be obtained via the seesaw mechanism, whereby one takes advantage of the key qualitative distinction between the neutrinos and the other fermions: right-handed neutrinos are gauge singlets, and may therefore have large Majorana masses. The standard seesaw mechanism, however, does not address the apparent lack of hierarchy in the neutrino masses compared to the quarks and charged leptons, nor the large leptonic mixing angles compared to the small angles of the CKM matrix.
The IceCube neutrino observatory is the world's largest high-energy neutrino telescope, utilizing the deep Antarctic ice as the Cherenkov detector medium. In December 2010 the last of the observatory's 86 strings of optical detectors was deployed, completing the approximate cubic-kilometer array. With the addition of a low-energy extension, called DeepCore, the observatory has very high neutrino detection efficiency for energies ranging from ~10 GeV to a few EeV. The low-energy threshold establishes the first steps towards precision neutrino measurements in the Antarctic.
Direct dark matter (DM) detection experiments almost always focus on Weakly Interacting Massive Particles (WIMPs), which have a mass in the 1--1000 GeV range. However, what if DM is not a WIMP? In this talk, new direct detection strategies for DM particles with MeV to GeV mass will be presented. In this largely unexplored mass range, DM can scatter with electrons, causing ionization of atoms in a detector target material and leading to single- or few-electron events. I will present the first direct detection limits on DM as light as a few MeV, using XENON10 data.