The PROSPECT-II physics goals*

The Precision Reactor Oscillation and SPECTrum (PROSPECT) experiment consists of a segmented liquid scintillator antineutrino detector located 7m from the highly-enriched High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory that aims to explore short-baseline antineutrino oscillations. Its first phase of data collection, called PROSPECT-I, ran from 2018 to 2019 and resulted in several high- precision analyses, including multiple 235U antineutrino spectrum measurements and eV-scale sterile antineutrino oscillation searches.

The collaboration is now preparing for its second phase, called PROSPECT-II. With an upgraded detector design, PROSPECT-II will allow us to expand beyond the current analyses, with improved sen- sitivity and statistics. In this talk, I will discuss how we expect PROSPECT-II to add to first-generation oscillation and spectrum results. I will also describe new analysis studying how isotopic Inverse Beta Decay (IBD) yield constraints, especially for sub-dominant isotopes, can be improved by systematics- correlated IBD measurements at HEU and LEU reactors, which can be performed in the future with the more robust PROSPECT-II detector.