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Atomic nuclei play an important role in the evolution of matter in our universe. For many problems in astrophysics, cosmology, and particle physics, the detailed properties of atomic nuclei provide essential inputs to the solutions.
Our group's research focuses on studying nuclei experimentally to probe fundamental questions about our universe. For example, we measure nuclear reactions, decays, and masses in the laboratory to learn about the reactions that power exploding stars or affect their synthesis of chemical elements. Similar experiments can contribute to searches for physics beyond the standard model of particle physics. In some cases we can use these low energy nuclear physics techniques to directly measure the reactions that occur in stars or to directly search for new physics.
Our program at NSCL is currently focused on measuring the beta decays of proton-rich nuclides. With these experiments, we hope to constrain the nuclear structure details that are most influential on the explosive burning of hydrogen on the surfaces of accreting compact stars such as white dwarfs and neutron stars. Additionally, these experiments can allow us to better constrain the effects of isospin-symmetry breaking in nuclei on tests of the unitarity of the Cabibbo-Kobayashi-Maskawa matrix, a cornerstone of the standard model.
Students in our group have opportunities to propose, prepare, execute, analyze, and interpret nuclear -physics experiments at NSCL, to publish the results in leading scientific journals, and to present the results at national and international conferences.
Selected Nuclear Structure and Fundamental Symmetries Publications:
Superallowed 0+ ➛ 0+ β decay of T = 2 20Mg: QEC value and βγ branching, B. E. Glassman, D. Perez-Loureiro, C. Wrede et al., arXiv:1910.12965
25Si β+ decay spectroscopy, L. J. Sun, M. Friedman, T. Budner, D. Perez-Loureiro, E. Pollacco, C. Wrede et al., Phys. Rev. C 103, 014322 (2021)
First Penning trap mass measurement of 36Ca, J. Surbrook et al., Phys. Rev. C 103, 014323 (2021)
Improved limits on Fierz Interference using asymmetry measurements from the UCNA experiment, X. Sun et al. (UCNA Collaboration), Phys. Rev. C 101, 035503 (2020)
Doppler Broadening in 20Mg(β p γ)19Ne Decay, B. E. Glassman, D. Perez-Loureiro, C. Wrede et al., Phys. Rev. C 99, 065801 (2019)
Toward complete spectroscopy using β decay: the example of 32Cl(β γ)32S, E. Aboud, M.B. Bennett, C. Wrede et al., Phys. Rev. C 98, 024309 (2018)
Search for dark matter decay of the free neutron from the UCNA experiment: n ➛ χ + e+e-, X. Sun et al. (UCNA Collaboration), Phys. Rev. C 97, 052501(R) (2018)
New result for the neutron β-asymmetry parameter A0 from UCNA, M. A.-P. Brown et al. (UCNA Collaboration), Phys. Rev. C 97, 035505 (2018)
First direct constraints on Fierz interference in free-neutron β decay, K. Hickerson et al. (UCNA Collaboration), Phys. Rev. C 96, 042501(R) (2017)
Confirmation of the isomeric state in 26P, D. Perez-Loureiro, C. Wrede et al., Phys. Rev. C 96, 014306 (2017)
β-delayed γ decay of 26P: Possible evidence of a proton halo, D. Perez-Loureiro, C. Wrede et al., Phys. Rev. C 93, 064320 (2016)
Isobaric multiplet mass equation in the A = 31, T = 3/2 quartets, M. B. Bennett, C. Wrede et al., Phys. Rev. C, 93, 064310 (2016)
Revalidation of the Isobaric Multiplet Mass Equation for the A=20 Quintet, B. E. Glassman, D. Perez-Loureiro, C. Wrede et al., Phys. Rev. C, 92, 042501(R) (2015)
Decay studies for neutrino physics, A. García et al., Hyperfine Interact. 223, 201 (2014)
Precision measurement of the neutron β-decay asymmetry, M. P. Mendenhall et al. (UCNA Collaboration), Phys. Rev. C 87, 032501(R) (2013)
Electron capture on 116In and implications for nuclear structure related to double-β decay , C. Wrede et al., Phys. Rev. C 87, 031303(R) (2013)
Measurement of the neutron β-asymmetry parameter A0 with ultracold neutrons, B. Plaster et al. (UCNA Collaboration), Phys. Rev. C 86, 055501 (2012)
Precision measurement of the 6He half-life and the weak axial current in nuclei, A. Knecht et al., Phys. Rev. C 86, 035506 (2012)
Precision Measurement of the 6He Half-Life and the Weak Axial Current in Nuclei, A. Knecht et al., Phys. Rev. Lett. 108, 122502 (2012)
Determination of the Axial-Vector Weak Coupling Constant with Ultracold Neutrons, J. Liu et al. (UCNA Collaboration), Phys. Rev. Lett. 105, 181803 (2010)
Toward precise QEC values for the superallowed 0+ ➛ 0+ β decays of T = 2 nuclides: The masses of 20Na, 24Al, 28P, and 32Cl, C. Wrede et al., Phys. Rev. C 81, 055503 (2010)
Nuclear structure relevant to neutrinoless double β decay: The valence protons in 76Ge and 76Se, B. P. Kay et al., Phys. Rev. C 79, 021301(R) (2009)
Nuclear Structure Relevant to Neutrinoless Double β Decay: 76Ge and 76Se, J. P. Schiffer et al., Phys. Rev. Lett. 100, 112501 (2008)
Pair correlations in nuclei involved in neutrinoless double β decay: 76Ge and 76Se, S. J. Freeman et al., Phys. Rev. C 75, 051301(R) (2007)