Dr. Christian's work is centered around using direct nuclear reactions as a tool for studying both nuclear astrophysics and nuclear structure. On the astrophysics side, Dr. Christian, his group, and their collaborators use nucleon transfer reactions to indirectly constrain the rates of key reactions driving nucleosynthesis in explosive stellar environments, such as novae, supernovae, and X-ray bursts. Ultimately, this work strives to answer "big picture" questions such as "Where do the chemical elements come from?" and "What are the processes driving stellar evolution and stellar explosions?". On the structure side, the focus of Dr. Christian's group is on using nucleon transfer reactions to populate and study excited states in "exotic" nuclei - or nuclei with extreme neutron-to-proton ratios, far away from stability. These nuclei display a varity of fasciniting phenomena, such as neutron "halos", or extended matter radii, as well as exotic decay modes including "dineutron emission", or the emission of correlated neutron pairs.
S. Ota, G. Christian, G. Lotay, W.N. Catford, E.A. Bennett, S. Dede, D.T. Doherty, S. Hallam, J. Hooker, C. Hunt, H. Jayatissa, A. Matta, M. Moukaddam, G.V. Rogachev, A. Saastamoinen, J.A. Tostevin, S. Upadhyayula, and R. Wilkinson. “Decay properties of 22Ne+α resonances and their impact on s-process nucleosynthesis.” Physics Letters B, 802, 135256, Mar 2020.
G. Lotay, P. J. Woods, M. Moukaddam, M. Aliotta, G. Christian, B. Davids, T. Davinson, D. T. Doherty, D. Howell, V. Margerin, and C. Ruiz. “High-resolution radioactive beam study of the 26Al(d,p) reaction and measurements of single-particle spectroscopic factors.” The European Physical Journal A, 56(1), Jan 2020.
D. Connolly, P. D. O'Malley, C. Akers, A. A. Chen, G. Christian, B. Davids, L. Erikson, J. Fallis, B. R. Fulton, U. Greife, U. Hager, D. A. Hutcheon, S. Ilyushkin, A. M. Laird, A. Mahl, and C. Ruiz. “Direct measurement of resonance strengths in S34(α,γ)Ar38 at astrophysically relevant energies using the DRAGON recoil separator.” Phys. Rev. C, 97(3), 035801, Mar 2018. Should be considered "leftover postdoc work". No significant work was done on this paper while I was at TAMU.
G. Christian, G. Lotay, C. Ruiz, C. Akers, D. S. Burke, W. N. Catford, A. A. Chen, D. Connolly, B. Davids, J. Fallis, U. Hager, D. Hutcheon, A. Mahl, A. Rojas, and X. Sun. “Direct measurement of astrophysically important resonances in K38(p,γ)Ca39.” Phys. Rev. C, 97(2), 025802, Feb 2018. A significant portion of the data analysis and manuscript writing were performed while I was at TAMU, and TAMU affiliation is listed on the paper. This paper was also selected for an editor's highlight in the Physics journal.