Beyond the Standard Model with Precision Nucleon Matrix Elements on the Lattice

Precision measurements of nucleons provide constraints on the Standard Model and can discern the signatures predicted for particles beyond the Standard Model (BSM). Knowing the Standard Model inputs to nucleon matrix elements will be necessary to constrain the couplings of dark matter candidates such as the neutralino, to relate the neutron electric dipole moment to the CP-violating theta parameter, or to search for new TeV-scale particles though non-$V-A$ interactions in neutron beta decay. However, these matrix elements derive from the properties of quantum chromodynamics (QCD) at low energies, where perturbative treatments fail. Using lattice gauge theory, we can nonperturbatively calculate the QCD path integral on a supercomputer. In this proceeding, I will discuss a few representative areas in which lattice QCD (LQCD) can contribute to the search for BSM physics, emphasizing suppressed operators in neutron decay, and outline prospects for future development.Comment: 3 pages, 2 figures, talk presented at the 19th Particles and Nuclei International Conference (PANIC 2011), Massachusetts Institute of Technology, Cambridge, MA, USA, July 24-29, 201

Invasion of a littoral cladoceran Sida crystallina into the pelagic zone of Christine Lake, NH and its potential impact on the phytoplankton community

This study evaluated the phytoplankton community and grazing influences of the zooplankton in oligotrophic Christine Lake, NH, by assessing the body size and clearance rates of the three dominant crustaceans: Sida crystallina (0.08 individuals L-1 ), Daphnia dubia (0.11 individuals L-1 ), and Leptodiaptomus sicilis (2.11 individuals L-1 ). Sida crystallina, typically a littoral cladoceran, was abundant throughout the water column in the open water, and contributed approximately 44% of the grazing in the pelagic zone. Phytoplankton abundance was examined to assess the potential impact S. crystallina might have on the phytoplankton in Christine lake. Aphanocapsa, the dominant phytoplankton in Christine Lake (relative abundance 68.54%), is a picocyanobacterium capable of forming colonies in the presence of planktonic grazers. Its ability to out-compete other phytoplankton due to differential grazing pressure suggests the appearance of the strong grazer S. crystallina may have contributed to the dominance of cyanobacteria in this oligotrophic lake

Atmospheric Secondary Particles In Near Earth Space

The Alpha Magnetic Spectrometer detects a large amount of particles below rigidity cutoff. Those high energy particles create questions related to radiation belts and atmospheric neutrinos. To understand the origin of these particles, we use a trajectory tracing program to simulate particle trajectories in realistic geomagnetic field. The complex behaviors and large e^+/e^- are explained here.Comment: 6 pages, 5 figures; Submit to the 8th Asia Pacific Physics Conferenc