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Organized by: Prof. Lu Lu

Events During the Week of April 29th through May 6th, 2018

Monday, April 30th, 2018

No events scheduled

Tuesday, May 1st, 2018

No events scheduled

Wednesday, May 2nd, 2018

No events scheduled

Thursday, May 3rd, 2018

Fission and the formation of the r-process rare-earth abundance peak in neutron star mergers
Time: 2:30 pm
Place: 5280 Chamberlin Hall
Speaker: Nicole Vassh, University of Notre Dame
Abstract: The recent observations of the GW170817 electromagnetic counterpart
suggest lanthanides were produced in this neutron star merger event.
However many questions regarding heavy element production in mergers
remain: can such events account for all the r-process lanthanide material
observed in the galaxy? are precious metals such as gold produced in
sufficient amounts? are actinides produced? where within the merger
environment does nucleosynthesis occur and under what specific conditions?
Such questions can only be answered with careful studies of the nuclear
physics uncertainties affecting r-process calculations. Here I will
discuss recent extended calculations of beta-delayed fission and their
implications for r-process nucleosynthesis. The influence of fission
fragment distributions will also be addressed with a particular emphasis
on the unknown origin of the r-process rare-earth peak at A~164. Since the
rare-earth peak is formed as the r-process path begins to draw closer to
stability, the rare-earth nuclei contributing to peak formation will soon
be within reach of nuclear physics experiments performed at, for example,
the CPT at CARIBU and the upcoming FRIB. Here I will present the latest
results for the masses found to produce the rare-earth peak in a low
entropy accretion disk wind scenario and compare directly with recent mass
measurements from the CPT at CARIBU. Such collaborative efforts between
theory and experiment could soon be in a position to make definitive
statements regarding the mechanism of rare-earth peak formation and thus
the astrophysical site of the r process.
Host: Baha Balantekin
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Friday, May 4th, 2018

No events scheduled