| Date | Speaker (link to SPIRES) |
Title (abstract) |
| 7th Sept 2006 (Thu) |
Winfried
Leidemann (Univ. Trento) |
The
LIT method: an Ab-Initio Approach for the Calculation of Reactions in
Light Nuclei The Lorentz integral transform (LIT) method is discussed for inclusive and exclusive electromagnetic reactions. The LIT approach allows the rigorous inclusion of final state interaction for a reaction into the A-body continuum state, however without using an A-body continuum wave function. In fact the LIT method reduces a scattering problem to a bound state like problem thus leading to an enormous simplification. Applications of the LIT will be discussed for the inclusive three-body electrodisintegration and exclusive electromagnetic reactions on 4He. |
| 14th Sept 2006 (Thu) * |
Lisa
Kaufman (Univ. of Massachusetts) |
Parity-violating
Electron Scattering and Strangeness in the Nucleon:
Results from HAPPEX-II Parity violation in elastic electron scattering is sensitive to possible strange quark contributions to the vector structure of the nucleon, and this provides an opportunity to isolate effects of the qq-bar sea. The HAPPEX collaboration in Hall A at Jefferson Lab has measured the parity-violating asymmetry in the scattering of longitudinally-polarized 3 GeV electrons from Hydrogen and Helium cryogenic targets at a scattering angle of 6 degrees and low Q^2. The asymmetry for Hydrogen is sensitive to a linear combination of the strange quark contributions to the electric (G_E^s) and magnetic (G_M^s) form factors of the proton while the Helium asymmetry is senstive only to G_E^s. The combination of the two measurements allows G_E^s and G_M^s to be separately determined. Final results will be presented. |
| 21st Sept 2006 (Thu) |
no seminar
(Chiral Dynamics 2006, Duke) |
|
| 28th Sept 2006 (Thu) |
no seminar |
|
| 5th Oct 2006 (Thu) * |
Dean
Lee (North Carolina State Univ.) |
Cold
Dilute Neutrons -- A New Type of Superfluid? I discuss the superfluid ground state and excitations of spin-1/2 fermions in the unitary limit. The unitary limit describes an interesting bit of universal physics that occurs when the range of the attractive force between particles is negligible and the strength of the interaction is tuned to produce a zero-energy resonance. I discuss relevance to dilute neutron matter, cold atomic Fermi gas experiments, and new theoretical results. |
| 12th Oct 2006 (Thu) |
Giuseppina
Orlandini (Univ. Trento) |
A recent ab
initio method for bound state like problems in few-body systems I will illustrate the main idea of the EIHH method, which couples the theory of effective interaction (EI) to the Hyperspherical Harmonics (HH) formalism. This method allows to obtain accurate bound state solutions of Schroedinger and Schroedinger-like equations. The method is quite general and can be applied to both boson and fermion systems. In the second part of the seminar I will present some applications of the method to nuclear systems with A=4,6,7. In particular I will discuss the results of the first complete four-body calculation of the photonuclear cross section of 4He, with realistic two- and three-body forces. These results have been obtained using the EIHH method within the Lorentz Integral Transform framework. |
| 19th Oct 2006 (Thu) |
Edward
L. Tomusiak (Victoria Univ.) |
Extracting Higher-q Results from
Non-Relativistic Models In the field of few body nuclear physics there exist various methods of performing accurate nuclear calculations within the framework of non-relativistic quantum mechanics. Relativity usually appears in the form of various relativistic corrections applied to components of the theory. These non-relativistic calculations must become increasingly inaccurate as momentum transfers increase. The question then arises as to the possibility of performing the calculations in such a manner as to extend their validity. One measure of the lack of covariance in non-relativistic calculations is frame-dependence of calculated quantities. We show several methods, some intuitive, by which frame dependence can be decreased in the calculation of 3N electromagnetic response functions. These techniques give agreement with data at higher momentum transfers than what would normally be expected. |
| 26th Oct 2006 (Thu) |
no seminar (DNP Fall Meeting, Nashville) |
|
| 2nd Nov 2006 (Thu) * |
Raju
Venugopalan (Brookhaven Natl. Lab) |
From Color
Glass Condensate to Quark Gluon Plasma (via the Glasma) in RHIC's
little Bang The hottest and densest matter on earth, comparable to those that existed 0.000001 seconds after the Big Bang, is being studied at BNL's Relativistic Heavy Ion Collider (RHIC). At RHIC, gluonic matter in the wavefunctions of the colliding Gold nuclei (the Color Glass Condensate) melts in the collision to form a state of matter called the Glasma, which subsequently thermalizes to form a Quark Gluon Plasma. We outline our theoretical understanding of this chronology of events and discuss some of the open questions that remain in our understanding of RHIC's little Bang. |
| 9th Nov 2006 (Thu) |
no seminar (APS meeting SE-section) |
|
| 16th Nov 2006 (Thu) |
no seminar (EFT workshop Bad Honnef) |
|
| 23rd Nov 2006 (Thu) |
no seminar (Thanksgiving) |
|
| 30th
Nov 2006 (Thu) * |
Diane
Markoff (North Carolina Central Univ. and ) |
Fundamental Neutron Physics at
the Oak Ridge Spallation Neutron Source Studies involving the neutron - neutron properties, neutron decay and neutron scattering - provide important tests for the Standard Model of electroweak interactions and for probing physics beyond the Standard Model. In the past decade, advances in technology for the production and transport of low-energy neutron beams, including polarized neutrons, have enabled the development of precision measurements testing fundamental symmetries and the weak interaction. With a new neutron source coming online, the reduction of statistical and systematic limitations holds promise, thereby increasing the precision of measurements and the opportunities to probe new physics in the next generation of experiments. The construction of the Spallation Neutron Source (SNS) at the Oak Ridge National Laboratory was officially completed in May 2006. A high-energy beam of protons hits a mercury target producing neutrons through the spallation process. The neutrons are moderated and slowed to thermal energies and below. When ramped to full power, the SNS will provide the most intense pulsed neutron beams available for scientific research and industrial development. One beam line at the SNS has been designated for fundamental neutron physics research in which proposed experiments include precision measurements of neutron beta-decay parameters, studies of the quark-quark weak interaction and the search for a neutron electric dipole moment. This seminar will include an introduction to the Fundamental Neutron Physics Beamline at the SNS, and to the scientific program proposed for the initial years of operation. |
| 4th Dec 2006 (Mon) special! 2:00pm Cor 104 |
Christoph
Hanhart (FZ Jülich) |
How to
identify hadronic molecules Although studied for many years the nature of the light scalar mesons remains controversial. Here we shall present a method, applicable for s-wave states located close to a threshold, that allows one to quantify the molecular part of a given state. When applied to the $f_0(980)$ a dominance of the molecular component is found. In the second part we show that requirements of field theoretic consistency and chiral symmetry, when applied to the scattering of light pseudo--scalars, naturally lead to the appearance of dynamical poles in the scalar sector. A program is proposed on how to further investigate experimentally the mixing between these dynamical states and possible genuine quark states. Also some thoughts will be given on how to extend the concept to baryons. |
Back to Center
for Nuclear Studies Home Page, Department of Physics
Home Page.
Harald W. Griesshammer,
5th October 2006