学术报告: Cosmological Lithium Problems
报告人 :Prof. Carlos A. Bertulani
(Department of Physics and Astronomy, Texas A&M University-Commerce, USA)
时间 :1月11日上午10 :00, 地点 : 田家炳楼南205
Abstract : Big Bang nucleosynthesis (BBN) theory predicts the abundances of the light elements D, 3He, 4He, and 7Li produced in the early universe. The primordial abundances of D and 4He inferred from observational data are in reasonable good agreement with predictions. However, BBN theory overestimates the primordial 7Li abundance by about a factor of three. This is the so-called “cosmological lithium problem.” A second lithium puzzle exists in connection to the 6Li/7Li abundance ratio. Solutions of these problems using conventional astrophysics and nuclear physics have not been successful over the past few decades, probably indicating the presence of new physics during the BBN epoch. I will discuss recent work on the cosmological lithium problems.
As a famous expert living in the pecan forest of the northern corner in Dallas, Prof. Bertulani has a broad interest in Nuclear physics and astrophysics.He has worked on reactions with nuclei far from the stability: halo nuclei, effective field theories, three-body systems, mean-field models, statistical theory of nuclear reactions, radiative capture reactions, fusion, direct reactions, neutron stars, relativistic heavy ion reactions. Though his works mainly focus on the nuclear nutshell, his ambition--not limited to it—lets out on the Big Bang phenomena. Since he got his PhD at University of Bonn, Germany, June 1987, Thesis: Summa Cum Laude, he has authored more than 260 papers including those published in Nature, Science, Phys. Rev. Lett, Phys. Rept, and written or edited more than 11 textbooks or novel books. He is active in academic communions in the world including Asia China in recent years with his colleagues being touched by his inexhaustible diligence, humorous wisdom, and high productivity. A few of his latest publications can be witnessed:
1. Test of the Brink-Axel Hypothesis for the Pygmy Dipole Resonance, D. Martin, P. von Neumann-Cosel, A. Tamii, N. Aoi, S. Bassauer, C. A. Bertulani, et al., Phys. Rev. Lett. 119, 182503 (2017).
2. On the determination of the 7Be(n,alpha)4He reaction cross section at Big Bang Nucleosynthesis energies, L. Lamia, C. Spitaleri, C. A. Bertulani, S.Q. Hou, M. La Cognata, R.G. Pizzone, S.Romano, M.L. Sergi, A. Tumino, Astrophys. J. 850, 175 (2017).
3. Peeling off neutron skins from neutron-rich nuclei: Constraints on the symmetry energy from neutron-removal cross sections, T. Aumann, C.A. Bertulani, F. Schindler, S. Typel, Phys. Rev. Lett., accepted (2017).
4. Quasi-free (p,2p) reactions on oxygen isotopes: Observation of isospin independence of the reduced single-particle strength, Leyla Atar, S. Paschalis, C. Barbieri, C.A. Bertulani, et al., Phys. Rev. Lett., accepted.
5. Non-extensive Statistics Solution to the Cosmological Lithium Problem, S.Q. Hou, J.J. He, A. Parikh, D. Kahl, C.A. Bertulani, T. Kajino, G.J. Mathews and G. Zhao, Astrop. J 834, 165 (2017).
This paper is cited as a Research Highlight by the American Astronomical Society.
6. Electric dipole polarizability of 48Ca and implications for the neutron skin, J. Birkhan, M.
Miorelli, S. Bacca, S. Bassauer, C.A. Bertulani, et al., Phys. Rev. Lett. 118, 252501 (2017).
7. Four neutrons together momentarily, C.A. Bertulani and V. Zelevinsky, Nature 17884 (2016).
8. Relativistic Coulomb excitation within Time Dependent Superfluid Local Density
Approximation, I. Stetcu, C. Bertulani, A. Bulgac, P. Magierski, and K.J. Roche, Phys. Rev. Lett. 114, 012701 (2015).