LNS Special Seminars
Monday, June 23, 2008
11AM, Kolker Room 26-414
Joshua G. Rubin (University of Illinois, Urbana-Champaign)
"Unraveling the Quark Helicity Distributions of the Nucleon at HERMES"
The spin-physics community has come to understand that the spin-composition of the nucleon is a surprisingly complex puzzle. One piece of this puzzle, the quark helicity distributions, which describe the contributions of the spins of quarks of particular flavors, have been extracted through semi-inclusive deep-inelastic scattering by the HERMES collaboration. Using observed double-spin asymmetries and the Lund-String Monte Carlo model of the fragmentation process, a five-flavor leading-order extraction has been performed. Along with the published HERMES results, progress toward an improved analysis will be presented: this new analysis will significantly reduce statistical and systematic uncertainties and will explore previously uninvestigated features of the quark polarizations.
Thursday, May 15th
Joseph Steele, University of Colorado
"Constraining the Polarization of the Proton's Glue with the η Meson at PHENIX"
Friday, May 9, 2008
Dr. Markus Klute, Göttingen University
“The Origin of Mass”
For decades particle physicists have been searching for the last missing particle predicted by the Standard Model, the Higgs boson. With the first collisions at the LHC scheduled to begin in only a few months, the hunt for the Higgs boson will soon enter a new phase. Provided that it is not first discovered at the Tevatron, we are confident of our ability to discover the Higgs boson at the LHC if the collider, ATLAS, and CMS perform to their specifications (and assuming that it does in fact exist). The discovery would raise many new questions: Is the new particle really the SM Higgs? How does it couple to the various particle types and to itself? Do more Higgs bosons exist? What is the origin of elementary particle masses?
Friday, February 15, 2008
Michael Mulhearn, Columbia University
"Toward Standard Model Sensitivity: The Higgs Saga at the Tevatron "
The Standard Model predicts a Higgs Boson as the mechanism for spontaneous breakin gof the electroweak gauge symmetry, which produces a massless photon but massive W and Z bosons. The Higgs, which has so far eluded detection, would complete a remarkable list of experiementally confirmed Standard Model predictions. I summarize the search for the Higgs Boson at the D0 experiment, emphasizing recent efforts to reach Standard Model sensitivity. The upgraded Level-1 Calorimeter Trigger at the D0 experiment allows continued data taking at higher instantaneous luminosities, adding crucial additionla data to the search at a faster rate. Meanwhile, advanced analysis techniques are used to extract maximal sensitivity from the available data. I close with a review of Fermilab's prospects for taking the prize: a Higgs discovery.
Friday, February 22nd
Ellit Lipeles, University of Califormia, San Diego
"The Search for the Higgs and Diboson Production at the Energy Frontier"
At the core of the standard model of particle physics is the mechanism of electroweak symmetry breaking. The key ingredient of this mechanism, the Higgs boson, has yet to be seen. I present a search for the Higgs decay to the WW final state and measurements diboson production which is sensitive to the electroweak symmetry breaking predictions for the couplings between gauge bosons.
Friday, February 29th
Dmitri Tsybychev, SUNY at Stony Brook
"Looking for new physics in the Bs-meson system"
Friday, March 7th
Andrea Pocar, Stanford University
"EXO and Borexino: ultra-low background experiments for neutrino physics"