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Nuclear Physics Seminar

The Nuclear Physics Seminars are held in Room 304 of the Nielsen Physics Building, at 2:25 pm. Please note that the Department of Physics and Astronomy Colloquium follows our seminars at 3:30 pm in room 307 of the Science and Engineering Research Facility (SERF).

Fall 2018 Schedule
Date
Speaker
Title
Host

August 27

Rin Yokoyama
Department of Physics and Astronomy, UTK

Recent measurements at RIKEN and their impact on the production of elements in the universe.

Rin Yokoyama

September 10

Zhengyu (Shu) Xu
Department of Physics and Astronomy, UTK

Experimental studies on the nuclear moments of the intruder 1+ isomer in 34Al.

Zhengyu Xu

September 17

Andrew Steiner
Department of Physics and Astronomy, UTK

Equation of State, Superfluidity and Superconductivity in Dense Nucleonic Matter

Andrew Steiner

September 24

Nathan Brewer
Joint Institute for Nuclear Physics and Applications/Oak Ridge National Laboratory

Search for the heaviest atomic nuclei among the products from reactions of mixed-Cf with a 48Ca beam aka 294 and the real Og

Robert Grzywacz

October 1

Marija Vostinar
Department of Physics and Astronomy, UTK

The puzzle of the unbound 13Be

Marija Vostinar

October 8

Charlie Rasco
Joint Institute for Nuclear Physics and Applications/Oak Ridge National Laboratory

TBA

Robert Grzywacz

October 15

Noah Birge
Department of Physics and Astronomy, UTK

Looking for Beyond the Standard Model Physics in 45Ca beta decay

Noah Birge

October 22

Jaki Noronha-Hostler
Department of Physics and Astronomy, Rutgers, the State University of New Jersey

TBA

Christine Nattrass/Soren Sorensen

October 29

Miguel Madurga
Department of Physics and Astronomy, UTK

TBA

Miguel Madurga

November 5

Wael Elkamhawy
TU Darmstadt

TBA

Lucas Platter

November 12

Andy Castro
Department of Physics and Astronomy, UTK

TBA

Andy Castro

November 19

Nicole Vassh
University of Notre Dame

TBA

Kate Jones

November 26

Evan Adamek
Department of Physics and Astronomy, UTK

TBA

Evan Adamek


Abstracts
August 27
Rin Yokoyama, University of Tennessee

Recent measurements at RIKEN and their impact on the production of elements in the universe.

RI-beam Factory (RIBF) at RIKEN Nishina Center is an exotic heavy-ion research facility in Japan. This facility is able to provide high-intensity beams of various unstable nuclei far from the line of beta stability. At the beginning of this talk, I will give some introduction to the facility and show recent researches going at RIKEN. Then, I will present a recent result from BRIKEN collaboration. BRIKEN is a high-efficiency array of 3He neutron counters designed to measure beta-delayed neutron branching ratios in the decays of very neutron-rich nuclei which is important to understand the production of elements in the universe. We measured beta-delayed one- and two-neutron emission of 86Ga and 87Ga and observed large one-neutron emission probability in 87Ga compared to the two-neutron emission, which was not expected from our shell model calculation. We found that this can be explained well by combining Hauser-Feshbach statistical model to the shell model calculation. This means that there is a strong one-neutron emission occurring even from the two-neutron unbound states in daughter nuclei. The result is the first experimental demonstration that it is important to take the competition between one- and two-neutron emissions into account to predict decay properties of very neutron-rich nuclei which may affect final abundance of elements in the universe.

September 10
Zhengyu (Shu) Xu, University of Tennessee

Experimental studies on the nuclear moments of the intruder 1+ isomer in 34Al.

An experiment has been carried out at GANIL to measure the nuclear moments of the low-lying 1+ isomer in 34Al (N=21) using the beta-NMR technique. Unlike its 4- ground state, of which the wave function is strongly mixed with 0p0h and 2p2h components, the 1+ isomer is proposed to have a dominant 1p1h configuration. Even though the excitation energy of this isomer has been reported recently, its 1p1h nature remains to be verified experimentally. In this presentation, I will present the g factor and quadrupole moment of the isomer newly determined from our recent work. The isomer's 1p1h character can be firmly identified by comparing the experimental g factor with either the effective single-particle g factor, or more complex shell-model calculations. The quadrupole moment, on the other hand, increases roughly by 50% with respect to that of the 32Al ground state (also a 1+state), suggesting an enhanced deformation induced by the 1p1h excitation across N=20. In addition, shell-model calculations of 32-34Al using several different effective interactions are compared with available experimental data in various observables, to gain a deeper insight on the neutron particle-hole excitation in this transitional region.


September 17
Andrew Steiner, University of Tennessee

Equation of State, Superfluidity and Superconductivity in Dense Nucleonic Matter.
Nuclear experiments tightly constrain the properties of the nucleon-nucleon interaction near or below the nuclear saturation density. At higher densities, however, there is considerable uncertainty because high-density matter cannot be generated in the laboratory without also creating high temperatures. Neutron star observations provide constraints on cold and dense matter which cannot be obtained from experiment. We use these observations to determine the equation of state and the nature of nucleonic superfluidity. In particular, X-ray observations of neutron stars provided gravitational wave predictions which were verified late last year. Observations of neutron star cooling are beginning to constrain the neutron-to-proton ratio in dense matter as well as the magnitudes of the neutron superfluid gaps and proton superconducting gaps.


September 24
Nathan Brewer, Joint Institute for Nuclear Physics and Applications/ Oak Ridge National Laboratory

Search for the heaviest atomic nuclei among the products from reactions of mixed-Cf with a 48Ca beam aka 294 and the real Og
The search for new decay chains of oganesson isotopes is presented. The experiment utilized the Dubna Gas Filled Recoil Separator and a highly segmented recoil-decay detection system. The signals from all detectors were analyzed in parallel by digital and analog data acquisition systems. For the first time, a target of mixed californium (51% 249Cf, 13% 250Cf, and 36% 251Cf)recovered from decayed 252Cf sources was produced and irradiated with an intense 48Ca beam. The observation of a new decay chain of 294Og is reported. Time permitting, a demonstration of the data will also be shown.



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