Nuclear/High Energy Seminar Abstracts
Fall 2009
|
The Majorana experiment is a search for the neutrinoless double-beta decay of germanium-76 using enriched, high-purity germanium as both source and detector. The current half-life limit for this decay is 1.9 x 10^{25} years, making background suppression of paramount importance for upcoming experiments. I will present work on understanding and mitigating backgrounds, particularly those from decays of radioactive isotopes on and near the surfaces of germanium detectors. I will also review some of the physics that motivates neutrinoless double-beta decay searches as well as the design and status of the Majorana experiment. |
|
We shall discuss the various mechanisms potentially at work in hadroproduction of heavy quarkonia at RHIC, Tevatron and LHC energies in the light of computations of higher-order QCD corrections both in the colour-singlet (CS) and colour-octet (CO) channels and the inclusion of the contribution arising from the /s/-channel cut in the CS channel. Besides, we will discuss new observables meant to better discriminate between these different mechanisms, including associated production and correlation measurements. On the other hand, we will show how the kinematics specific to the J/psi production matters for the extraction of Cold Nuclear Matter effects, e.g. the shadowing of the gluon distribution in nuclei. |
|
It has been known for years that inclusive electron scattering to the continuum of complex nuclei (e,ex) shows scaling properties, with several observables condensed into one to represent a large range of data. If such scaling could be seen also with hadrons, through the veil of the strong interaction, we could enlarge the range of nuclear responses to be obtained from the wide variety of hadronic reactions. Essentially all relevant global hadron data have been subjected to analyses similar to those for electrons. Methods to deal with the strong complications have been developed and tested, resulting in some remarkably simple scaling results. This talk will emphasize use of the Bjorken scaling variable xB at values greater than unity, where multinucleon correlations are to be sought. |
|
The Pierre Auger Observatory is a multi-national project for research on ultra-high energy cosmic rays. The Southern Auger Observatory (Auger South) in Mendoza province, Argentina, was completed in 2008 with an instrumented area of 3,000 km**2. Science results form Auger South motivate the completion and extension of the investigations begun there by constructing the Northern Auger Observatory (Auger North), with a much larger acceptance for the extremely rare cosmic ray events above a few times 10**19 eV. Auger North will have an instrumented area of 8,000 square miles (20,000 km**2) in Southeast Colorado, USA. The presentation covers the science of Auger North, the layout and the technical implementation, as well as current R&D efforts underway in Colorado.
|