Bulletin of the American Physical Society
74th Annual Meeting of the Southeastern Section
Volume 52, Number 13
Thursday–Saturday, November 8–10, 2007; Nashville, Tennessee
Session JA: Highlights of Nuclear Physics at Laboratories in the Southeast |
Hide Abstracts |
Chair: David Ernst, Vanderbilt University Room: Scarritt-Bennett Center Laskey Great Hall |
Friday, November 9, 2007 1:30PM - 2:00PM |
JA.00001: Nuclear Physics Program at the Upgraded High Intensity $\gamma$-ray Source (HI$\gamma$S) Invited Speaker: Recent upgrades to the High Intensity $\gamma$-ray Source (HI$\gamma$S) at the Duke Free Electron Laser Laboratory have produced unprecedented $\gamma$ ray intensities with selectable polarization and energy resolution. A newly commissioned 1.2 GeV Booster Injector has enabled the facility to deliver $\gamma$ rays up to 65 MeV with sustained flux. Recently performed benchmark tests of the $\gamma$ ray flux between 2 and 40 MeV will be presented. A broad nuclear physics program is in its initial phase of execution. The planned experiments include cross section measurement of key reactions in nuclear astrophysics, nuclear structure studies, measurements of the Gerasimov-Drell-Hearn (GDH) sum rule integrand for $d$ and $^3$He, and measurement of electromagnetic and spin polarizabilities of nucleons. An overview of the experiment to measure the $^{16}$O($\gamma,\alpha$)$^{12}$C reaction cross section in order to determine the cross section of the inverse reaction at astrophysically relevant energies will be presented. A brief report on nuclear structure studies involving parity assignments and transition strengths will be presented. Lastly, experiments have been designed to improve the presently available data on the proton and the neutron electromagnetic polarizabilities and to provide the first data on the spin polarizabilities of the nucleons. [Preview Abstract] |
Friday, November 9, 2007 2:00PM - 2:30PM |
JA.00002: Beta decay studies around doubly magic 78Ni Invited Speaker: The main motivations to study very neutron rich nuclei in the $^ {78}$Ni region are related to the evolution of nuclear structure and to the path of nucleosynthesis within rapid neutron capture. In particular, neutrons filling g$_{9/2}$ orbital between $^{68}$Ni and $^{78}$Ni affect spin-orbit splitting of proton single-particle states. An increasing beta- delayed neutron emission probabilities are changing the isobaric distributions of nuclei involved in the r-process. The report on the recent results on the decay of most neutron- rich isotopes of copper and gallium [1] will be presented. These proton-induced $^{238}$U fission products were produced and studied at Holifield Radioactive Ion Beam Facility at Oak Ridge using a ``ranging-out'' method [2] for postaccelerated beams purification. In collaboration with Jeff Winger and Sergey Iliushkin, Mississippi State University; Carl Gross and Dan Shapira, ORNL; Carrol Bingham, UTK; Robert Grzywacz, ORNL; Chiara Mazzocchi, Sean Liddick, Steven Padgett, and Mustafa Rajabali, UTK; Jon Batchelder, UNIRIB-ORAU; Edward Zganjar and Andreas Piechaczek, LSU; Christopher Goodin and Joseph Hamilton, Vanderbilt University; and Wojciech Krolas, JIHIR Oak Ridge.\newline [1] J. Winger et al., contr. to INPC, Japan, June 2007\newline [2] C.J. Gross et al., EPJ A 25, s01, 115 (2005) [Preview Abstract] |
Friday, November 9, 2007 2:30PM - 3:00PM |
JA.00003: Collective Phenomena in the Quark-Gluon Plasma produced at RHIC Invited Speaker: Recently, the experimental collaborations based on the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory announced the discovery of an extraordinarily dense and hot state of matter which exhibits properties of a near perfect fluid. While it was expected that at RHIC energies the head-on collisions of gold ions will lead to deconfinement of the quarks and gluons inside them, the quark-gluon plasma (QGP) showed surprising collective properties contrary to the expectations for a gas of free quarks and gluons. The matter ``flows,'' i.e. - responds collectively to variations of pressure across the volume formed by the colliding nuclei, with very small viscosity. Recent measurements on 2-particle and multi-particle correlations reveal that the matter also responds collectively to a fast particle propagating through it. Is it a sound wave, Cherenkov radiation of gluons or some other excitation moving through the QGP? This talk will review the experimental results and the proposed theoretical explanations for the observed collective phenomena. [Preview Abstract] |
Friday, November 9, 2007 3:00PM - 3:30PM |
JA.00004: Precision test of the Standard Model in parity-violating electron--proton scattering Invited Speaker: The Standard Model has been enormously successful at predicting the outcomes of experiments in nuclear and particle physics. The search for new physical phenomena and a fundamental description of nature which goes beyond the Standard Model is driven by two complementary experimental strategies. The first is to build increasingly energetic colliders, such as the Large Hadron Collider (LHC) at CERN, which aim to excite matter into a new form. The second, more subtle approach is to perform precision measurements at moderate energies, where an observed discrepancy with the Standard Model will reveal the signature of these new forms of matter. Here we use precision parity-violating electron scattering measurements on nuclear targets to extract the weak charges of the quarks. The result is found to be in excellent agreement with the predictions of the Standard Model. Combining this result with earlier measurements of the low-energy weak force, most notably data on parity violation in atomic cesium, lifts the relevant energy scale for physics beyond the Standard Model to almost 1 TeV. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700